OPINION OF THE COURT
ALITO, Circuit Judge.The Commissioner of the Pennsylvania Department of Corrections (hereinafter “the Commonwealth”) appeals from a District Court order granting the petition for a writ of habeas corpus that was filed by Ronald Rompilla, a Pennsylvania prisoner who was sentenced to death. The District Court ordered that Rompilla be released unless he is either resentenced to life imprisonment or a new penalty phase trial is held. Rompilla cross-appeals from the denial of his petition insofar as it challenged his conviction. We conclude that the Pennsylvania Supreme Court’s decision regarding Rompilla’s sentencing proceeding was not contrary to and did not involve an unreasonable application of clearly established Supreme Court precedent, and therefore we reverse the decision of the District Court with respect to Rompilla’s sentence. We affirm the decision of the District Court with respect to his conviction. By separate order, however, we have granted Rompilla’s application to file a successive petition for a writ of habeas corpus so that he will be able to assert his claim that, under Atkins v. Virginia, 536 U.S. 304, 122 S.Ct. 2242, 153 L.Ed.2d 335 (2002), he may not be executed because of mental retardation.
*236I.
In 1988, Rompilla was tried for the murder of James Scanlon. Scanlon’s body was found lying in a pool of blood in his bar, the Cozy Corner Café in Allentown, Pennsylvania. Scanlon had been stabbed repeatedly and set on fire. There were no eyewitnesses to the killing, but the Commonwealth introduced substantial circumstantial evidence of Rompilla’s guilt. In its opinion on direct appeal, the state supreme court summarized the prosecution’s evidence as follows:
Appellant was seen in the Cozy Corner Café on January 14, 1988, from approximately 1:00 a.m. to 2:00 a.m. During that time, he was observed going to the bathroom approximately ten times. A subsequent police investigation determined that the window in the men’s bathroom was used as the point of entry into the bar after it had closed.
When questioned by an investigating detective from the Allentown Police Department, Appellant stated that he had been in the Cozy Corner Café on the night of the murder and left between 2:00 a.m. and 2:30 a.m. because he had no money. He stated that he had only $2:00 to buy breakfast at a local diner. A cab driver testified that he picked up Appellant at the diner and drove him to two different hotels where Appellant was unable to rent a room. The driver then took Appellant to the George Washington Motor Lodge where he was able to rent a room. Appellant paid the cab fare of $9.10.
Appellant rented a room for two nights at the George Washington Motor Lodge. In doing so, he paid $121.00 in cash and flashed a large amount of cash to the desk clerks. Appellant also used a false name when he checked in.
The police secured a search warrant ■for Appellant’s motel room and seized several items, including Appellant’s sneakers. These sneakers matched a footprint in blood that was discovered near the victim’s body. In addition, the blood found on the sneakers matched the victim’s blood type.
The Commonwealth also presented other circumstantial evidence that linked Appellant with the robbery and murder of James Scanlon. First, Mr. Scanlon’s wallet was found by a groundskeeper in the bushes, six to eight feet outside the room that Appellant had rented at the George Washington Motor Lodge. Second, Appellant’s fingerprint was found on one of the two knives used to commit the murder. Finally, there were numerous inconsistencies between what Appellant had told the police concerning his activities on January 14 and 15, 1988, and the testimony of other witnesses.
Commonwealth v. Rompilla, 539 Pa. 499, 653 A.2d 626, 629 (1995). The jury found Rompilla guilty of first degree murder and other related offenses.
At the penalty phase of the trial, the prosecution attempted to establish three aggravating factors: (1) that Rompilla committed the murder while perpetrating a felony, 42 Pa.C.S. § 9711(d)(6), namely, the burglary and robbery of the bar; (2) that he committed the murder by means of torture, 42 Pa.C.S. § 9711(d)(8); and (3) that he had a significant history of felony convictions involving the use or threat of violence to the person, 42 Pa.C.S. § 9711(d)(9). To establish torture, the Commonwealth called Dr. Isidore Mihalak-is, a forensic pathologist, who testified to the multiple wounds inflicted on Scanlon *237and opined that Scanlon was conscious and alive when many of those wounds were inflicted. App. 698-707. Based on the nature of the wounds, Dr. Mihalakis also opined that Scanlon’s killer had deliberately attempted to inflict pain before Scanlon died. Id. at 707-08. To show the defendant’s prior history of violent felonies, the Commonwealth proved that he had been convicted in 1976 of rape, burglary, and theft. App. 651-52. Commonwealth v. Rompilla, 250 Pa.Super. 139, 378 A.2d 865 (1977). The testimony of the rape victim, which was read into the record, showed that Rompilla had burglarized a bar after closing and had raped the bar owner and slashed her with a knife. App. 662-696.
The defense presented the testimony of five members of the Rompilla family. Rompilla’s older brother, Nicholas, and his wife, Darlene, testified that Rompilla had lived in their home with their children for the three and one-half months before the killing. Nicholas testified that he and the defendant had grown up together, that the defendant had worked for him as a house painter before his arrest, and that the defendant had also helped out around the house. App. 738-41. Nicholas said that he had visited his brother frequently in prison and that they had a good relationship. Id. at 739. Nicholas added that he did not think that his brother had killed Scanlon, whom he had known for about 10 or 11 years, and that his heart went out to the Scanlon family. Id. at 740. He concluded his testimony by asking the jury to have mercy on his brother. Id. at 741.
Darlene Scanlon testified that her children were “very attached” to the defendant and that he “was very good in our house.” App. 734-35. Darlene said that he helped out in the home and that “he was a good family member” who felt “strongly about family” and “respected the family very well.” Id. at 735. While the defendant was in prison, Darlene testified, he frequently -wrote to her and spoke about “[fjamily, his son, his wife, his brothers and sisters.” Id. She stated that the defendant’s relationship with his son was good. Id. at 736. Like her husband, Darlene testified that she had known Scanlon, that she did not believe that the defendant had killed him, and that she felt for the Scanlon family “[v]ery, very much.” Id. Weeping, she concluded her testimony by telling the jury: ‘We go to bed crying, we wake up crying, it’s been very hard on my children.... [W]e want Ron alive even if it’s in jail, we want him alive.” Id.
Another brother, Bobby, also took the stand. Bobby testified that during the time when the defendant was out of prison they had an “[ejxcellent relationship” and were “[vjery close.” App. 745. Before then, according to Bobby, he had visited the defendant in prison and the defendant had written him letters in which he expressed great concern for his son and other family members. Id.
The defendant’s sister, Sandra Whitby, testified that she had grown up with the defendant. App. 754. Crying, she said that she loved him very much and that she thought that he was a “good person.” Id. at 755. Asked what things were important for the defendant, she answered: “Family, his son, his wife, things my children were doing, my brothers.” Id. She testified that she was praying for the Scanlon family and for her brother’s life. Id. at 756. She added: “[WJe’re not God, and we can’t take people’s lives (crying) ... I love my brother. Taking one life is never going to replace another life.” Id.
Finally, Aaron Rompilla, the defendant’s 14-year old son testified. He said that after his father’s release from prison they had regular visits, which he enjoyed, that his father was proud of him, that he loved his father, and that he would visit him if he was sentenced to prison. Id. at 757-59. He said that he did not think it would be *238“right” to sentence his father to death, and when he was asked whether there was anything else he wanted to tell the jury, he simply cried. Id. at 759.
In her closing argument, defense counsel made an impassioned plea for Rompil-la’s life. Her closing appears to have had three major themes. First, she repeatedly stressed that, although the jury had found the defendant guilty, they must have had at least some lingering doubt about what had happened, and therefore they should not sentence him to death, which “is final, irreversible.” Id. Second, she reminded the jury of the good qualities mentioned by Rompilla’s family members. She argued that Rompilla was “more than this act that you have found him to have committed,” id. at 769, and she emphasized the love of Rompilla’s family members. Id. at 773. She particularly asked the jury to keep in mind the defendant’s 14 year old son, who had come to court to ask the jury “not to kill his father.” Id. Third, she pled for mercy and warned the jury: “I tell you this from the bottom of my heart, if you order death, it will take a part of your life away. Don’t stain your hands and your souls with this man’s blood, don’t do it please.” Id. at 772.
After deliberating, the jury unanimously found all three of the aggravating circumstances alleged by the prosecution, and the jury stated that one or more members found two mitigating factors under the “catchall” provision of 42 Pa.C.S. § 9711(e)(8), i.e., “Rompilla’s son being present and testifying” and the possibility of rehabilitation. The jury found that the aggravating circumstances outweighed the mitigating factors and sentenced Rompilla to death.
The Pennsylvania Supreme Court affirmed the conviction and sentence. Commonwealth v. Rompilla, 539 Pa. 499, 653 A.2d 626 (1995) (hereinafter “Rompilla-1 ” )1 In December 1995, Rompilla filed a petition under the Pennsylvania Posh-Conviction Relief Act (“PCRA”). After an evi-dentiary hearing, the PCRA denied the petition, and the Pennsylvania Supreme Court affirmed. Commonwealth v. Rom-pilla, 554 Pa. 378, 721 A.2d 786 (1998) (hereinafter “Rompilla-2”).
Rompilla then filed a petition for a writ of habeas corpus pursuant to 28 U.S.C. § 2254 in the United States District Court for the Eastern District of Pennsylvania. Rompilla’s petition raised 11 claims. Rompilla v. Horn, No. Civ.A.99-737, 2000 WL 964750 (E.D.Pa. July 11, 2000).2 The District Court denied relief as to'the guilt phase but granted relief as to the penalty *239phase based on its conclusion that counsel had been ineffective in failing to investigate and present mitigating evidence. Id. at *14. The District Court thus ordered that a writ of habeas corpus would be granted unless the Commonwealth conducted a new sentencing hearing or resen-tenced Rompilla to life imprisonment. Id. at *21. The Commonwealth appealed, and Rompilla cross-appealed. Three questions are presented on appeal: (1) whether Rompilla’s trial counsel was constitutionally ineffective during the penalty phase; (2) whether the trial court committed constitutional error in giving an accomplice liability instruction; and (3) whether the trial court erred in failing to instruct the jury that “life imprisonment” under Pennsylvania law meant life without the possibility of parole.3
II.
Because the District Court did not conduct an evidentiary hearing, our review of that Court’s decision is plenary. Duncan v. Morton, 256 F.3d 189, 196 (3d Cir.), cert. denied, 534 U.S. 919, 122 S.Ct. 269, 151 L.Ed.2d 197 (2001). However, our review of the decision of the Pennsylvania Supreme Court is circumscribed by the Anti-terrorism and Effective Death Penalty Act of 1996 (“AEDPA”). See Hartey v. Vaughn, 186 F.3d 367, 371 (3d Cir.1999). Under AEDPA, a federal court may not grant habeas relief on any claim adjudicated on the merits in state court unless the adjudication
(1) resulted in a decision that was contrary to, or involved an unreasonable application of, clearly established Federal law, as determined by the Supreme Court of the United States; or
(2) resulted in a decision that was based on an unreasonable determination of the facts in light of the evi*240dence presented in the State court proceeding.
28 U.S.C. § 2254(d). Under the “contrary to” clause of § 2254(d)(1), relief may be ordered if the state court arrived at “a conclusion opposite to that reached by [the Supreme] Court on a question of law” or if the state court decided “a case differently than [the Supreme] Court has on a set of materially indistinguishable facts.” Williams v. Taylor, 529 U.S. 362, 412-13, 120 S.Ct. 1495, 146 L.Ed.2d 389 (2000). Under the “unreasonable application” clause of § 2254(d)(1), relief may be awarded if the state court identified the correct governing legal principle from Supreme Court decisions but unreasonably applied that principle to the facts of the case, id., or was “unreasonable in refusing to extend the governing legal principle to a context in which the principle should have controlled,” Ramdass v. Angelone, 530 U.S. 156, 166, 120 S.Ct. 2113, 147 L.Ed.2d 125 (2000). Relief may not be granted under the “unreasonable application” clause merely because the federal court “concludes in its independent judgment that the relevant state-court decision applied clearly established federal law erroneously or incorrectly. Rather, that application must also be unreasonable.” Williams, 529 U.S. at 411, 120 S.Ct. 1495. See also Bell v. Cone, 535 U.S. 685, 122 S.Ct. 1843, 1850, 152 L.Ed.2d 914 (2002) (“The focus ... is on whether the state court’s application of clearly established federal law is objectively unreasonable, and we stressed in Williams that an unreasonable application is different from an incorrect one.”). Furthermore, a federal court “must presume that the factual findings of both state trial and appellate courts are correct.” Everett v. Beard, 290 F.3d 500, 508 (3d Cir.2002) (citing 28 U.S.C. § 2254(e)(1)). This presumption may be rebutted only by clear and convincing evidence. 28 U.S.C. § 2254(e)(1).
III.
Rompilla claims that his trial attorneys were ineffective at the penalty phase. First, Rompilla alleges that his attorneys were derelict in failing to obtain school, hospital, court, and prison records that reveal a number of IQ test results in the mentally retarded range, low achievement scores, placement in special education classes, childhood neglect, problems with alcohol, and an alcoholic mother. Second, he faults his attorneys for failing to provide such records to the psychologist and the two psychiatrists whom they retained to examine him and for allegedly failing to communicate adequately with these experts. Third, he alleges that his attorneys were negligent in interviewing members of his family. He criticizes trial counsel because they did not interview two sisters who did not testify at the penalty phase, and because they did not ask sufficiently specific questions when they interviewed other family members. Fourth, Rompilla charges that his attorneys were derelict in failing to investigate the possible effects on Rompilla of childhood trauma and alcoholism.
A.
Rompilla was represented by two public defenders, Frederick- Charles, who was then the Chief Public Defender for Lehigh County, and Maria Dantos, a full-time assistant public defender. App. 1055-56, 1059. Both testified at length at the PCRA hearing. For present purposes, two aspects of these attorneys’ preparation for the penalty phase are most pertinent: first, their efforts to obtain information about Rompilla’s childhood and schooling and, second, their communications with the three mental health professionals whom they consulted.
*241Both Charles and Dantos explained that the defense had questioned Rompilla and numerous members of his family about his childhood, schooling, and background and had asked for any information that might be helpful at sentencing. According to their testimony, however, neither Rompilla himself nor any family member even hinted at the problems on which Rompilla’s ineffective assistance claim is based. Dan-tos testified that she had developed a good relationship of trust with Rompilla, that she felt that she had gotten to know him, and that she had a lot of discussions with Rompilla “about who he was and his life.” App. 1073, 1163. When she asked Rompil-la about school, Dantos recounted, he told her “[t]hat there was nothing unusual about it.” Id. at 1197. Dantos also said that she specifically asked Rompilla about drinking and that he responded that he sometimes drank but “could handle it” and was not an alcoholic. Id. at 100-01. On the night of the killing, Rompilla told her, he had consumed three or four beers over the course of the entire evening. Id. at 1101.
Charles added that Rompilla had responded to questions about his background by saying that nothing was wrong:
“Is there anything that happened? What was it like growing up? Is there anything you can tell us that could help us?” And he said, “No, there was nothing wrong.” He was very, very, smooth about it. It wasn’t that he was reluctant to talk about anything. He said, “Your conversations about the possibility of the death penalty bore me.” ...
There was no indicator from anything he told us that would send us searching for ... any kind of records. He said everything was fine. He had a normal childhood. There was nothing there....
... I remember [Dantos] specifically going one by one and talking to him. ‘Is there anything you can tell me? Tell me about yourself. Tell by about your background.’ She was, you know, meticulous to cover points.
App. 1303. Both Dantos and Charles said that nothing in their discussions with Rom-pilla ever suggested that he was mentally retarded, id. at 1181, 1393, and Charles elaborated that Rompilla did not have difficulty in understanding what was said to him or in expressing his feelings. Id. at 1393.
Dantos and Charles also testified that members of Rompilla’s family provided no hint that Rompilla had mental problems, had suffered child abuse, or was an alcoholic. Dantos stated that she spoke with three of Rompilla’s siblings, his sister-in-law Darlene Rompilla, and his ex-wife and that she had formed a “very close” relationship with the family. App. 1092, 1065. She said that they had discussed the importance of mitigation evidence but that no one had provided any useful information about Rompilla’s background. She testified that she had “spent hours with these family members,” that they had “discussed the family dynamics and what [Rompilla’s] family relationship was with his parents,” and that there was no indication “that there was any sort of abuse within the family.” Id. at 1097 Likewise, she stated that “there was nothing exceptional presented to [her] about drinking within the family.” Id. Charles added that although the family members said that they did not know Rompilla well because he had spent so many years behind bars, the family was a “constant source of information.” Id. at 1303,1384.
Charles was questioned repeatedly and extensively by Rompilla’s attorneys about the failure of the defense to look for *242school, prison, and medical records, and Charles explained his strategy as follows:
I would investigate by asking- my client, “how was your childhood? Were there any problems that you suffered? Any kind of abuse? [I]s there anything that sticks out? Don’t think whether it’s important or not. You just tell us, and then we’ll determine whether or not we can use it.” Investigate it that way. Would I send somebody to the person’s elementary school to talk to the teacher to see if they remember him from 25 years or 40 years before. No. I didn’t have those resources in the office.... I had two investigators and 2,000 cases.... I will talk to the client, talk to the family, and see if anything developed from there.
Id. at 1293-94. If these inquiries provided any hint that records would be helpful, he added, he would go anywhere to get the records. Id. at 1307.
With respect to the development of mitigation evidence regarding Rompilla’s mental condition, Charles said that he had sent Rompilla to “the best forensic psychiatrist around here, to [another] tremendous psychiatrist and a fabulous forensic psychologist” and that he relied on them to detect any mental problems that might be useful to the defense and to request that the defense provide them with any records that they might need. App. 1307-08. He elaborated that when he sent Rompilla to the psychologist, he expected the psyeholo-
gist to administer “a Reitan battery test to determine if there was any brain damage,” 4 a personality test such as “the Minnesota Multiphasic Personality Inventory (“MMPI”)”,5 a Rorschach test,6 and an IQ test. Id. at 1323. He stated that he also expected that the results of this testing would be available to the psychiatrists. Id. If the mental health professionals needed any records or other information, he said, he expected them to ask for them, and he would have tried to provide whatever they sought. Id. He said that he also thought that the mental health professionals would interview Rompilla and that they would detect whether Rompilla’s denial of anything unusual in his background seemed suspicious. Id. at 1308-09.
All three of the mental health professionals to whom Rompilla had been sent by the defense testified at the PCRA hearing either in person or by deposition. All three stated that they had examined Rom-pilla and had found nothing useful to the defense, but as Rompilla now stresses, all three also testified that, if they had been provided with Rompilla’s school and other records, they would have done additional testing.
Dr. Gerald Cooke, an experienced clinical and forensic psychologist, no longer possessed records regarding his examination of Rompilla other than the letter that he had sent to the public defender’s office after completing the examination, but he was able to state with “99 percent” certain*243ty what he would have done in a case of that type. App. at 1797. In a death penalty case, he testified that one of the questions in his mind would have been whether the defendant “showed any mental illness, emotional disturbance, or other sorts of problems that might be a psychological mitigating circumstance.” App. at 1808. He would have administered an MMPI, “an Incomplete Sentence Blank,7 the Rorschach inkblot technique, and two or three subtests of the verbal subscale of the Wex-ler Adult Intelligence WAIS Revised.”8 Id. at 1797. Dr. Cooke testified that he knew that the IQ test that he would have administered to Rompilla had not produced a score in the mentally retarded range because, in that event, he would have given further tests. Id. at 1810. He explained that he had not prepared a report regarding his examination because it was his practice to discuss the results of an examination orally with the referring attorney and to leave it to the attorney to decide whether he should prepare a report. Id. at 1816. He interpreted the letter that he wrote in this case to mean that he “didn’t have anything that [he] felt could be helpful.” Id.
Dr. Robert Sadoff, an experienced board-certified forensic psychiatrist, also had no records about Rompilla but testified that in a case of that type he would have examined the defendant for competency to stand trial, criminal responsibility, and mitigating circumstances. App. 1841, 1859. He would have questioned and observed the defendant and would have requested psychological testing if he thought it was necessary. Id. From the letter that he sent to the Public Defender’s Office, he said, it was fair to infer that he had found no mitigating evidence. Id. at 1859.
A second psychiatrist, Paul K. Gross, also testified that he had examined Rom-pilla prior to his trial at the request of the Public Defender’s office to determine his mental status at the time but was not asked to look for mitigating factors. App. 1504, 1506, 1549. Dr. Gross stated that Rompilla “denied any abuse as a child, by either parent.” Id. at 1517. According to Dr. Gross, Rompilla said that he had “a good relationship with his father” and a “fairly normal childhood except for the fact that he didn’t like school, which he left in the ninth grade.” Id. at 1517. Dr. Gross’s conclusion at the time was that, although there was some evidence of antisocial behavior, “[t]here was no other evidence for underlying psychiatric or mental disorder.” Id. at 1540. He added that he did not see anything in the materials shown to him by Rompilla’s attorneys at the PCRA hearing that would have changed his opinion. Id. at 1539-40. Dr. Gross also reported that although Rompilla denied it, there was a possibility that he could become violent while under the influence of alcohol.
In the PCRA proceedings, Rompilla presented testimony of three family members: two sisters, Barbara Harris and Randi Rompilla, who testified that they were not interviewed before sentencing, and Nicholas Rompilla, who had testified at the sentencing hearing. These family members stated, among other things, that their parents were alcoholics; that their mother drank while pregnant with Rompilla; that their father was physically abusive to the children and their mother; that Rompilla *244was locked in an outdoor dog pen; and that Rompilla was told he was stupid and would not amount to anything and was a very nervous child who kept everything inside. Nicholas testified that during the pre-sentencing interview he was asked only about the three months prior to the offense and was not asked about Rompil-la’s childhood. App. 1462-63, 1467-71, 1477-78.
Rompilla also presented evidence from two psychologists, Carol L. Armstrong and Barry Crown, both of whom had evaluated and tested Rompilla after he was convicted and sentenced. These psychologists’ evaluations included neuropsychological testing, review of Rompilla’s school, medical, and prison records, and review of post-sentencing declarations by Barbara Harris, Darlene Rompilla, and Nicholas Rom-pilla. The psychologists stated that the low IQ and achievement test results documented in Rompilla’s school records, his medical history, and his abusive background were all “red flags” indicating that further objective evaluation was necessary. App. at 1692,1739,1743.
Drs. Armstrong and Crown opined that Rompilla suffers from organic brain damage, an extreme mental disturbance significantly impairing several of his cognitive functions. They expressed the view that Rompilla’s problems relate back to his childhood and were likely caused by fetal alcohol syndrome, and they concluded that Rompilla’s capacity to appreciate the criminality of his conduct or to conform his conduct to the law was substantially impaired at the time of the offense. See Rompilla Br. at 58-61.
B.
In evaluating Rompilla’s ineffective assistance of counsel claim, the PCRA court noted that Strickland v. Washington, 466 U.S. 668, 104 S.Ct. 2052, 80 L.Ed.2d 674 (1984), requires proof of deficient performance and prejudice. App. 2027. The court then observed that Pennsylvania cases employ a three-pronged test:
First, a defendant must demonstrate that his claim is of arguable merit. In the event this threshold requirement is satisfied, a defendant must show that counsel had no reasonable basis for the act or omission in question. Finally a defendant must establish that but for counsel’s act or omission, the outcome of the proceedings would have been different.
App. 2028 (quoting Commonwealth v. Buehl, 540 Pa. 493, 658 A.2d 771 (1995)).
Applying this standard, the PCRA court concluded that Rompilla satisfied the first prong because he was “entitled to have relevant information of mental infirmity” presented to the jury, but the court held that the second prong was not met because “counsel had a reasonable basis for proceeding as they did during the penalty phase.” App. 2028. The court made the following findings:
Drs. Cooke and Sadoff, are “recognized experts in the field of psychiatry and psychology.”
“These experts administered tests, evaluated Mr. Rompilla, and reported back to defense counsel.”
They found “no organic brain damage” and “nothing that could be used in mitigation.”
They diagnosed Rompilla as a “sociopath,” and this evidence “would not have been of benefit to Mr. Rompilla’s case.”
The defense attorneys provided Drs. Cooke and Sadoff “with whatever they asked for,” and Drs. Cooke and Sadoff did not request the records later unearthed by PCRA counsel.
*245Trial counsel “also obtained an evaluation by Dr. Paul Gross, a well respected Lehigh Valley psychiatrist,” and Dr. Gross “found nothing that would have been beneficial in the penalty phase.”
Rompilla did not provide trial counsel with “any indication of mental problems or alcoholic blackouts” or anything else that was “particularly useful.”
Trial counsel “spoke with members of the family in a detailed manner,” and the family did not -reveal the family background information adduced in the PCRA proceeding.
The family members’ testimony at the PCRA hearing was not credible insofar as it “attempted to contradict what defense counsel indicated was asked of them during numerous communications prior to trial.”
App. 2028-2029.
Based on these findings, the PCRA concluded:
“Given the fact that [the] three health care professionals [retained by trial counsel], all of whom were experienced forensic experts, had provided opinions ..., and none of them asked for more information, it was hardly unreasonable or ineffective for defense counsel to have relied upon their opinions.”
Trial counsel was not ineffective in questioning family members because family members were questioned “in a detailed manner,” and contrary testimony at the PCRA hearing was rejected.
•
“Defense counsel was reasonable in believing that the only avenue available to them was to ask the jury to show mercy upon Mr. Rompilla.” “Under the circumstances of this case, this strategy was not only an appropriate one, but the only one reasonably available to counsel.”
On appeal, the Pennsylvania Supreme Court also held that Rompilla’s ineffective assistance claim lacked merit. The Court agreed with the PCRA court “that trial counsel was effective with respect to their investigation and presentation of mitigating evidence.” Rompillar-2,- 721 A.2d at 790. Noting that “trial counsel employed three experts to evaluate Appellant” and that “the experts found nothing helpful to Appellant’s case,” the Court added: “[W]e agree with the PCRA court that under the facts of this case, counsel reasonably relied upon their discussion with Appellant and upon their experts to determine the records needed to evaluate his mental health and other potential mitigating circumstances.” Id.
In the habeas proceeding, the District Court not only disagreed with the decisions of the PCRA court and the state supreme court on the ineffective assistance issue, but the District Court found that those decisions were unreasonable. Rom-pilla, 2000 WL 964750, at *14. However, the Court stated that its decision was “a very close call ... because trial counsel performed so admirably according to my review of the record” and further commented that its review of the record revealed that “trial counsel were intelligent, diligent and devoted to their task of representing [Rompilla].” Id. at *8, *12.
The District Court found two omissions in the opinions of the PCRA court and the state supreme court. First, the District Court stated, the prior opinions lacked “an in depth analysis of what the duty to investigate consists of in a case of this nature.” Id. at *8. In particular, the District Court faulted the state courts for failing to “include a reference to the ABA Standards for Criminal Justice.” Id. Second, the District Court found the state court opinions deficient for failing to discuss alcoholism. *246Id. at *8. Observing that it appeared that trial counsel “thought they could rely on the experts to determine [Rompilla’s] general mental ability or capacity,” the Court opined: “[I]t seems to me on balance that [trial counsel] were obliged to go a bit farther to fulfill their duty to investigate.” Id. at *9, *12. Concluding that trial counsel’s performance at the penalty phase had been inadequate and that Rompilla had been prejudiced, the Court held that Rom-pilla was entitled to habeas relief with respect to his sentence. Id. at *14.
IV.
Strickland is the Supreme Court precedent governing ineffective assistance of counsel claims, Williams, 529 U.S. at 391, 120 S.Ct. 1495, and in order to show ineffective assistance under Strickland, a defendant must demonstrate (1) that counsel’s “representation fell below an objective standard of reasonableness,” Strickland, 466 U.S. at 688, 104 S.Ct. 2052; and (2) that “there is a reasonable probability that, but for counsel’s unprofessional errors, the result of the proceeding would have been different.” Id. at 694, 104 S.Ct. 2052. “Judicial scrutiny of a counsel’s performance must be highly deferential,” and “every effort [must] be made to eliminate the distorting effects of hindsight, to reconstruct the circumstances of counsel’s challenged conduct, and to evaluate the conduct from counsel’s perspective at the time.” Id. at 689, 104 S.Ct. 2052. “There is a ‘strong presumption’ that counsel’s performance was reasonable.” Jermyn v. Horn, 266 F.3d 257, 282 (3d Cir.2001). Thus, “a defendant must overcome the presumption that, under the circumstances, the challenged action might be considered sound trial strategy.” Bell, 122 S.Ct. at 1852 (quotations omitted).
“The test for ineffectiveness is not whether counsel could have done more; perfection is not required. Nor is the test whether the best criminal defense attorneys might have done more. Instead the test is ... whether what [counsel] did was within the ‘wide range of reasonable professional assistance.’ ” Waters v. Thomas, 46 F.3d 1506, 1518 (11th Cir.1995) (en banc) (quoting Strickland, 466 U.S. at 689, 104 S.Ct. 2052). Ultimately, the issue is not what conduct is “prudent or appropriate, but only what is constitutionally compelled,” Burger v. Kemp, 483 U.S. 776, 794, 107 S.Ct. 3114, 97 L.Ed.2d 638 (1987) (quoting United States v. Cronic, 466 U.S. 648, 665 n. 38, 104 S.Ct. 2039, 80 L.Ed.2d 657 (1984)), and the Sixth Amendment “simply ... ensure[s] that criminal defendants receive a fair trial,” Strickland, 466 U.S. at 689, 104 S.Ct. 2052. See also Kokoraleis v. Gilmore, 131 F.3d 692, 696 (7th Cir.1997) (“The sixth amendment does not guarantee success or entitle defendants to the best available counsel or the most prudent strategies.... [T]he Constitution is satisfied when the lawyer chooses a professionally competent strategy that secures for the accused the benefit of an adversarial trial.”)
V.
In this appeal, the Commonwealth contends that the state courts reasonably applied the Strickland ineffective assistance standard to the facts of this case. According to the Commonwealth, the District Court erred by essentially considering the ineffective assistance issue as if it were conducting a de novo review — that is, by making its own independent application of the Strickland test to the facts rather than considei-ing only whether the state supreme court’s application of that test was reasonable. Rompilla of course disagrees, but he also goes further and argues that we need not reach the unreasonable appli*247cation issue at all for two reasons: first, because the Pennsylvania Supreme Court did not render a “decision” within the meaning of 28 U.S.C. § 2254(d)(1), and, second, because the state supreme court’s decision is “contrary to” Strickland. We discuss each of these arguments below.
A.
Rompilla argues that the Pennsylvania Supreme Court did not render a “decision” on his Sixth Amendment claim because “[t]he Pennsylvania Court’s opinion lacks any real Sixth Amendment analysis.” Rom-pilla Br. at 98. Rompilla criticizes the state supreme court for applying the three-pronged test set out in its own eases rather than the two-pronged Strickland test. Id. He contends that the relationship between the three-part Pennsylvania formulation and the Strickland test is “not clear,” and he faults that state supreme court for supposedly failing to address either prong of the Strickland test. Id. at 98-99. He asserts that the state supreme court mistakenly thought that his federal claim was that trial counsel did not conduct any investigation at all, whereas his actual claim was that trial counsel did not conduct a sufficiently “thorough” investigation. Id. at 100. Finally, he criticizes the state supreme court for failing “to render a.‘decision’ at all on critical aspects of this claim,” viz., the prejudice prong of Strickland and his arguments regarding alcoholism and intoxication. Id.
In order to address these arguments, we must first explain the critical difference under the habeas statute between, on the one hand, the failure of a state court to adjudicate a federal claim on the merits (something that may occur if the state court misconstrues the federal claim) and, on the other, the failure of a state court to hand down an opinion that discusses every argument, sub-argument, and legal authority offered by the habeas petitioner. For purposes of the habeas statute, a failure to decide affects the standard of review; a failure to discuss (either at all or to the satisfaction of the habeas petitioner or the federal court) is irrelevant.
Under the habeas statute, as previously noted, if a claim was “adjudicated on the merits” in a state court proceeding, relief may not be granted “unless the adjur dication of the claim ... resulted in a decision that was contrary to, or involved an unreasonable application of, clearly established Federal law.” 28 U.S.C. § 2254(d)(l)(emphasis added). An “adjudication on the merits” “has a well settled meaning: a decision finally resolving the parties’ claims, with res judicata effect, that is based on the substance of the claim advanced, rather than on a procedural, or other, ground.” Sellan v. Kuhlman, 261 F.3d 303, 311 (2d Cir.2001). See also Neal v. Puckett, 286 F.3d 230, 235 (5th Cir.2002) (“adjudication ‘on the merits’ is a term of art that refers to whether a court’s disposition of the case was substantive as opposed to procedural”), cert. denied, 537 U.S. 1104, 123 S.Ct. 963, 154 L.Ed.2d 772 (2003).
In Chadwick v. Janecka, 312 F.3d 597, 605-07 (3d Cir.2002), cert. denied, — U.S. —, 123 S.Ct. 1914, 155 L.Ed.2d 828 (2003), we discussed this issue in detail and reviewed both pertinent Supreme Court precedent and our own prior decisions in Everett v. Beard, 290 F.3d 500, 507-08 (3d Cir.2002), cert. denied, 537 U.S. 1107, 123 S.Ct. 877, 154 L.Ed.2d 777 (2003); Appel v. Horn, 250 F.3d 203, 210 (3d Cir.2001); and Hameen v. Delaware, 212 F.3d 226, 248 (3d Cir.2000). We noted that under Weeks v. Angelone, 528 U.S. 225, 237, 120 S.Ct. 727, 145 L.Ed.2d 727 (2000), a state court may render an adjudication or decision on the merits of a federal claim by rejecting the claim without any discussion whatsoev*248er. Chadwick, 312 F.3d at 606. We explained that if an examination of a state court opinion reveals that the state court did not decide a federal claim on the merits, the deferential standards of review set out in § 2254(d)(1) do not apply. Id. at 605-07. But if the state court decided the claim, the § 2254(d)(1) standards govern— regardless of the length, comprehensiveness, or quality of the state court’s discussion. Id. See also Sellan, 261 F.3d at 312 (a state court adjudicates a claim on the merits when it “(1) disposes of the claim ‘on the merits,’ and (2) reduces its disposition to judgment .... [e]ven if the state court does not explicitly refer to ... relevant federal case law.”); Bell v. Jarvis, 236 F.3d 149,160 (4th Cir.2000) (en banc) (section 2254(d) “does not require that a state court cite to federal law in order for a federal court to determine whether the state court decision is an objectively reasonable one.”), cert. denied sub nom., Bell v. Beck, 534 U.S. 830, 122 S.Ct. 74, 151 L.Ed.2d 39 (2001); Aycox v. Lytle, 196 F.3d 1174,1177 (10th Cir.1999) (“The focus is on the state court’s decision or resolution of the case.”); Wright v. Secretary for Dep’t of Corrections, 278 F.3d 1245, 1255 (11th Cir.2002) (section 2254(d)(1) “focuses on the result, not on the reasoning that led to the result”) cert. denied, 538 U.S. 906, 123 S.Ct. 1511, 155 L.Ed.2d 225 (2003).
Here, it is abundantly clear that the state supreme court adjudicated Rompilla’s Sixth Amendment claim on the merits. Although the state supreme court referred to its own three-pronged ineffective assistance test rather than the two-pronged Strickland test, the Pennsylvania Supreme Court has explicitly held that the state standard is “the same” as Strickland’ s and that Pennsylvania law does not provide “any greater or lesser protection” than the Sixth Amendment. Commonwealth v. Pierce, 515 Pa. 153, 527 A.2d 973, 976-77 (1987). As we put it in Werts v. Vaughn, 228 F.3d 178, 203 (3d Cir.2000) cert. denied, 532 U.S. 980, 121 S.Ct. 1621, 149 L.Ed.2d 483 (2001), the Pennsylvania Supreme Court has “opined that the Pennsylvania standard judging ineffectiveness claims [is] identical to the ineffectiveness standard enunciated by the United States Supreme Court in Strickland. ” Since the brief filed in the state supreme court on Rompilla’s behalf in the PCRA appeal left no doubt that the ineffectiveness claim asserted was based on federal law, it is perfectly clear that the state supreme court adjudicated that federal claim on the merits but simply chose to address the claim within the framework of its own, familiar three-part test, which it regards as “the same” as Strickland.
Moreover, it is apparent that this essentially stylistic choice on the part of the state supreme court had no effect on its decision. The state supreme court held that the second prong of the state formulation- — requiring a showing that “counsel had no reasonable basis for the act or omission in question,” Rompilla-2, 721 A.2d at 789 — had not been met because Rompilla’s trial “counsel acted reasonably” “with respect to their investigation and presentation of mitigation evidence.” Id. at 790. The second prong of the state formulation is substantively indistinguishable from the first prong of Strickland— which requires a showing that counsel’s “representation fell below an objective standard of reasonableness”. Strickland, 466 U.S. at 688, 104 S.Ct. 2052. Rompilla argues that the significance of the first Pennsylvania prong is unclear9 and that *249the third Pennsylvania prong differs from Strickland’s prejudice prong,10 Rompilla Br. at 98-99, but because the state supreme court held that Rompilla failed the second state prong, which is indistinguishable from the first Strickland prong, these arguments are entirely beside the point.
Rompilla’s remaining arguments on the question whether the state supreme rendered an “adjudication” or “decision” on the merits of his federal ineffectiveness claim require little additional discussion. There is plainly no merit to Rompilla’s argument that the state supreme court mistakenly thought that his Sixth Amendment claim was that counsel failed to conduct any investigation at all regarding the matters at issue and did not appreciate that his claim was that counsel did not conduct a sufficiently thorough investigation. Although the state supreme court did use the phrase “failed to investigate,” 721 A.2d at 790, it seems clear that this was simply a shorthand way of referring to the claim. The court’s discussion of the various steps that counsel took and its conclusion that counsel acted “reasonably” make it clear that the court did not think that any investigation at all would suffice but instead understood that the extent of the investigation had to be “reasonabl[e].”
What we have said about the relationship between the Pennsylvania formulation of the test for ineffective assistance and the Strickland formulation is sufficient to dispose of Rompilla’s criticism of the state supreme court for failing to discuss Strickland in so many words. Rompilla’s criticism of the state supreme court for failing to decide whether the prejudice prong of Strickland was satisfied is further flawed because, in light of the state supreme court’s holding that counsel’s performance was reasonable, the court had no need to address the issue of prejudice. See Strickland, 466 U.S. at 697, 104 S.Ct. 2052 (“[Tjhere is no reason for a court deciding an ineffective assistance claim to ... address both components of the inquiry if the defendant makes an insufficient showing on one.”); Sistrunk v. Vaughn, 96 F.3d 666, 673 n. 8 (3d Cir.1996) (if counsel’s performance is objectively reasonable, there is no need to decide prejudice).
Finally, Rompilla’s complaint that the state supreme court “failed to discuss any aspect” of his arguments regarding evidence of alcoholism and intoxication goes to the style of the state court’s opinion, not the question whether the state court rendered an adjudication on the merits. There are many different theories about how judicial opinions should be written. While some opinions make a point of specifically addressing every argument and every significant legal authority offered by counsel, others favor brevity and comment on only those points that the court finds most important. Because the state supreme court in this case rendered an “adjudication on the merits” of Rompilla’s Sixth Amendment claim, Rompilla’s criticisms of the state court’s opinion cannot *250free him from the restrictive standards of review set out in 28 U.S.C. § 2254(d)(1).
B.
There is similarly no merit in Rompilla’s contention that the decision of the state supreme court was “contrary to” Strickland because it did not “identify and apply actual Sixth Amendment standards.” Rompilla Br. at 101. A decision is “contrary to” a Supreme Court holding if the state court “contradicts the governing law set forth in [the Supreme Court’s] cases” or if it “confronts a set of facts that are materially indistinguishable from a decision of th[e Supreme] Court and nevertheless arrives at a [different] result.” Williams, 529 U.S. at 405-06, 120 S.Ct. 1495.
In this case, the critical standard applied by the state supreme court — whether trial counsel had a “reasonable basis for the act[s] or omission[s] in question” — did not contradict Strickland but rather, as we have explained, was entirely consistent with Strickland. In Werts v. Vaughn, 228 F.3d at 202-04, as noted, we compared Pennsylvania’s ineffective-assistance test with the test enunciated in Strickland, and we found that a state court decision that applied the Pennsylvania test did not apply a rule of law that contradicted Strickland and was thus not “contrary to” established Supreme Court precedent. Id. at 204. In the instant case, the state court applied the same state test. Accordingly, here, as in Werts, the state court’s application of that test does not mean that its decision is “contrary to” established Supreme Court precedent.
Rompilla also argues that the state court decision is contrary to Strickland because counsel’s failure to obtain records, without knowing the contents of the records, “cannot be deemed a reasonable strategy/tactic, as a matter of Sixth Amendment law, ” and because “Sixth Amendment law does not condition [the] obligation [to obtain records] in any way on counsel’s duties with regard to expert evaluations.” Rom-pilla Br. at 106, 108 (emphasis in original). Rompilla is essentially challenging the manner in which the state court applied the law to the facts, and thus this argument must be analyzed under the “unreasonable application” clause of § 2254(d)(1). See Williams, 529 U.S. at 406, 120 S.Ct. 1495 (a “run-of-the-mill state court decision” that is “in accord with ... Strickland as to the legal prerequisites for establishing an ineffective-assistance claim ... may be contrary to the federal court’s conception of how Strickland ought to be applied in that particular case” but is not contrary to Strickland itself). For these reasons, we reject Rompilla’s arguments under the “contrary to” clause of § 2254(d)(1).
VI.
We now turn to the ‘unreasonable application’ clause of § 2254(d)(1). To obtain relief under this clause, Rompilla
must do more than show that he would have satisfied Strickland’s test if his claim were being analyzed in the first instance, because under § 2254(d)(1), it is not enough to convince a federal habeas court that, in its independent judgment, the state-court decision applied Strickland incorrectly. Rather, he must show that the [state court] applied Strickland to the facts of his case in an objectively unreasonable manner.
Bell, 122 S.Ct. at 1852 (citation omitted). In other words, Rompilla must demonstrate that “the state court decision, evaluated objectively and on the merits, resulted in an outcome that cannot reasonably be justified under Strickland. ” Werts, 228 F.3d at 204.
*251We hold that the Pennsylvania Supreme Court’s conclusion that trial counsel acted reasonably and rendered effective assistance was not an unreasonable application of Strickland. The findings of the PCRA court and uncontradicted testimony at the PCRA hearing establish that trial counsel conducted an extensive investigation for mitigating evidence. According to their testimony, trial counsel got to know Rompilla well during the course of their representation and established a good relationship with him. Rompilla was questioned about his background but provided no useful information or leads. Trial counsel also spoke to three of Rompilla’s siblings, as well as a sister-in-law and Rompilla’s ex-wife. Family members were questioned “in a detailed manner,” but they did not allude to any of the new evidence adduced at the PCRA proceeding.
Trial counsel retained three well-qualified mental health experts to examine Rompilla. Dr. Cooke, a psychologist, testified that in a case of this type he would have looked for mitigating evidence and would have performed a battery of tests, including an IQ test. Based on his letter to the Public Defender’s office, he concluded that Rompilla’s IQ test must not have shown mental retardation and that his evaluation must not have revealed any abnormalities that would have been useful in showing mitigation. Dr. Sadoff, a.psychiatrist, interviewed Rompilla and evaluated him for the presence of mitigating factors, but Dr. Sadoff inferred that he also found nothing useful. A second psychiatrist, Dr. Gross, was also retained but similarly found nothing useful. In view of this record, we cannot say that the Pennsylvania Supreme Court unreasonably applied Strickland in concluding that trial counsel’s investigation regarding mitigating evidence relating to Rompilla’s family background and mental condition did not fall below the Sixth Amendment floor.
Rompilla criticizes many aspécts of trial counsel’s performance at the penalty phase, but we see no ground for relief under the habeas statute. Rompilla faults his trial attorneys for failing to interview two sisters who testified at the PCRA hearing — Barbara Harris, the oldest of Rompilla’s siblings, and Randi Rompilla, the second youngest. But trial counsel did interview three other siblings, including two who were a few years older than Rom-pilla (Nicholas Rompilla and Sandra Whit-by) and one Robert Rompilla, who was younger. At least some of the siblings who were interviewed must have been aware of the lurid conditions in the family home that were portrayed at the PCRA hearing, but they never mentioned anything about these matters to trial counsel despite being interviewed “in a detailed manner.” It was thus not constitutionally ineffective for trial counsel to fail to anticipate that interviewing Barbara Harris or Randi Rompilla would have yielded important new information about the family home.
Rompilla also criticizes his trial attorneys for allegedly failing to ask sufficiently specific questions when interviewing family members and for allegedly failing to ask Nicholas Rompilla about any time period other than the three and one-half months just before the murder. This argument is defeated by findings of fact made by the state courts. The PCRA found that trial counsel “spoke with members of the family in a detailed manner.” App. 2028. The PCRA court also rejected Nicholas Rom-pilla’s testimony insofar as it contradicted “what defense counsel indicated was asked ... during numerous conversations prior to trial.” Id. at 2030. Testimony at the PCRA hearing supports these findings. See, e.g., id. at 1303 (“I remember [Dantos] *252specifically going one by one and talking to him. ‘Is there anything you can tell me? Tell me about yourself. Tell by about your background.’ She was, you know, meticulous to cover points.”). The state courts’ findings must be presumed to be correct, and Rompilla has not rebutted that presumption “by clear and convincing evidence.” 28 U.S.C. § 2254(e)(1). We accordingly reject Rompilla’s argument regarding the interviewing of family members.
Rompilla contends that trial counsel should have sought out school, medical, police, and prison records, but this argument also falls short of meeting the AED-PA standard’. With the benefit of hindsight, we know that these records contain useful information about Rompilla’s childhood home environment, his mental problems, and his problems with alcohol, but trial counsel had grounds for believing that if there was any mitigating evidence of this sort to be found, at least a hint of its availability would be disclosed in the interviews with Rompilla and his family members or in the testing and evaluations performed by the three mental health experts whom they retained.
Charles, the lead trial attorney who had the final say on every issue in the case, App. 1258, explained why these records were not sought out. He testified that he would have done whatever was needed to get records if there had been any indication from the interviews or from the information provided by the mental health experts that such records would be helpful. Id. at 1307. But since these interviews and evaluations suggested that Rompilla’s home environment, schooling, and mental condition were not promising avenues of investigation in the search for mitigating evidence, he did not think that obtaining those records would have represented a sound allocation of his office’s resources. Id. at 1293-94.
This explanation provides a reasonable basis for counsel’s decision not to seek the records. Defense counsel was permitted to rely on statements made by their client in deciding on the extent of the investigation that should be conducted in particular areas. See Strickland, 466 U.S. at 691, 104 S.Ct. 2052 (“The reasonableness of counsel’s actions may be determined or substantially influenced by the defendant’s own statements or actions.”); id. (“[W]hen a defendant has given counsel reason to believe that pursuing certain investigations would be fruitless or even harmful, counsel’s failure to pursue those investigations may not later be challenged as unreasonable.”). As noted counsel’s interviews with Rompilla himself and with family members provided no indication of Rompilla’s abusive childhood or mental problems. See Thomas, 144 F.3d at 515 (“if the client and his family and friends throw the lawyer off the scent ... by denying the existence of psychological problems that might have provided an alternative theory of mitigation, the lawyer cannot be faulted for failing to go down the path thus closed off’). “The right to counsel does not require that a criminal defense attorney leave no stone unturned and no witness unpursued. [Although] it does require a reasoned judgment as to the amount of investigation the particular circumstances of a given case require[,][a]n attorney need not fully investigate every potential avenue if he or she has reasonable grounds for not doing so.” Berryman v. Morton, 100 F.3d 1089, 1101 (3d Cir.1996). See also Thomas v. Gilmore, 144 F.3d 513, 515 (7th Cir.1998) (“A reasonable investigation is not ... the investigation that the best criminal defense lawyer in the world, blessed not only with unlimited time and resources but also with the inestimable benefit of hindsight, would *253conduct.”) cert. denied, 525 U.S. 1123, 119 S.Ct. 907, 142 L.Ed.2d 905 (1999).
It was likewise not unreasonable for trial counsel to rely on its mental health experts to detect whether there was any basis for further pursuit of mitigating evidence relating to their client’s mental condition. Trial counsel retained no fewer than three highly qualified experts. Dr. Cooke and Dr. Sadoff looked for any evidence that could be used as mitigation but found none. A battery of tests was performed but yielded no indication of mental retardation or anything else that would have been useful for mitigation. Although all three of the experts testified that the records that PCRA counsel subsequently obtained would have caused them to do further investigation, none of the experts asked for records or suggested that any further testing be done.
In view of these circumstances, it was not unreasonable for the state courts to conclude that trial counsel did not fall below the constitutionally mandated level of representation by failing to search out the records at issue and by failing to provide those records to their mental health experts. This was not a case where counsel knew of the defendant’s mental health or other problems and failed to inform or provide the experts with the information. See Caro v. Calderon, 165 F.3d 1223, 1228 (9th Cir.1999) (“A lawyer who knows of but does not inform his expert witnesses about ... essential pieces of information going to the heart of the case for mitigation does not function as ‘counsel’ under the Sixth Amendment.”) cert. denied, sub nom, Woodford v. Caro, 527 U.S. 1049, 119 S.Ct. 2414, 144 L.Ed.2d 811 (1999). Despite counsel’s attempts to find out otherwise, counsel had no knowledge of Rompil-la’s problems and/or childhood abuse.11
In Card v. Dugger, 911 F.2d 1494 (11th Cir.1990), the court addressed an argument very similar to Rompilla’s argument regarding trial counsel’s failure to provide records to their mental health experts. In Card, a capital case, the mental health expert spoke to members of the defendant’s family and was provided copies of pre-trial reports indicating that the defendant was competent to stand trial. Id. at 1512. The expert testified at the sentencing hearing that the defendant suffered from a sociopathic personality disorder and that his abusive childhood was consistent with the development of the disorder. Id. at 1508. The defendant claimed that *254counsel was ineffective in failing to provide the expert with various school, incarceration, army, and medical records and information from family members. Id. at 1512. This information, the defendant argued, would have enabled the expert to diagnose the defendant as suffering from organic brain damage and schizophrenia, rather than merely a sociopathic personality. Id. at 1512-13. The Eleventh Circuit rejected this argument observing that
[t]here is no indication that the experts felt incapable of basing their conclusions on the information they obtained through their own testing and examinations. Nor is there any reason that, after receiving the experts’ reports, counsel was obligated to track down every record that might possibly relate to [the defendant’s] mental health and could affect a diagnosis.
Id. at 1512.
We find this reasoning persuasive. As in Card, there was no indication in the present case that Drs. Cooke, Sadoff, and Gross “felt incapable of basing their conclusions on the information they obtained through their own testing and examinations.” Card, 911 F.2d at 1512. Thus, it was not unreasonable for counsel to rely on the expertise and experience of the mental health professionals in determining the need for any records. Such deference to the legitimate role of experts is well within the wide range of reasonable professional assistance.
Furthermore, it was permissible for Charles to consider his office’s limited investigative resources in determining the extent of the investigation that should be conducted with respect to Rompilla’s childhood, family, and mental condition. See McWee v. Weldon, 283 F.3d 179, 188 (4th Cir.2002) (“the reasonableness of an investigation ... must be considered in light of the scarcity of counsel’s time and resources in preparing for a sentencing hearing”), cert. denied, 537 U.S. 893, 123 S.Ct. 162, 154 L.Ed.2d 158 (2002); Mahaffey v. Page, 151 F.3d 671, 685 (7th Cir.) (“A ‘reasonable investigation’ does not mandate a ‘scorch-the-earth strategy,’ a requirement that would fail to consider the limited time and resources that defense lawyers have in preparing for a sentencing hearing.”) (citations omitted), vacated in part on other grounds, 162 F.3d 481 (7th Cir.1998); Rogers v. Zant, 13 F.3d 384, 387 (11th Cir.1994) (the focus on whether a decision not to conduct a particular investigation was reasonable “reflects the reality that lawyers do not enjoy the benefit of endless time, energy or financial resources”).
Rompilla argues that his trial attorneys were deficient because they did not provide adequate information or instructions to Drs. Cooke, Sadoff, and Gross. Rompil-la maintains that his attorneys should have instructed Dr. Cooke to test for brain damage, but Charles testified that he relied on the experts to do whatever testing was appropriate. App. 1307-08. Dr. Cooke was aware of the need for mitigating evidence. He testified that in a capital case he would have looked for indications of “any mental illness, emotional disturbance, or other sorts of problems that might be a psychological mitigating circumstance,” and he performed the battery of tests that he felt was called for. Id. at 1808-09. He stated that if the results of some of those tests had provided a reason to do a “neu-ropsyche test,” he would have done so. Id. at 1809. Thus, Rompilla is in effect faulting his trial attorneys for failing to instruct an expert to do a test that the expert apparently did not think was warranted under the circumstances. This argument demands much more than the Sixth Amendment requires.
*255Rompilla criticizes his trial attorneys for allegedly failing to educate Dr. Sadoff about the meaning of mitigating evidence. Based on a snippet of Dr. Sadoffs testimony, Rompilla suggests that Dr. Sadoff thought that “mitigating evidence was limited to evidence about the offense itself,” Rompilla Br. at 87 (citing App. 1874), whereas under the law, “mitigation is anything that ‘might serve as a basis for a sentence less than death’ and need ‘not relate specifically to [the defendant’s] culpability for the crime he committed.’ ” Rompilla Br. at 88 (quoting Skipper v. South Carolina, 476 U.S. 1, 4-5, 106 S.Ct. 1669, 90 L.Ed.2d, 1 (1986)) (emphasis and brackets in original). There are at least three weaknesses in this argument.
First, in light of Dr. Sadoffs background — which included extensive experience relating to the criminal justice system (see App. 1876-1892) — it is far from clear that trial counsel had a constitutional obligation to brief him on the meaning of exculpatory evidence.12 Second, it also is not clear that Rompilla’s argument accurately represents what Dr. Sadoff said. Asked by Rompilla’s PCRA attorney whether he thought that evidence was mitigating only “if it relates to the defendant’s state of mind at the time of the commission of the offense,” Dr. Sadoff answered: “It relates to that and the kind of person he is .... ” App. 1874. (emphasis added). He continued that in the past he had not “used irrelevant material that had nothing to do with the crime itself as a mitigating factor. It had to be something that would have impacted on [the defendant’s] state of mind at the time.” Id. Thus, Dr. Sadoff did not say that he thought that mitigating evidence had to be evidence “about the offense.” Rompilla Br. at 87 (emphasis in original removed). Rather, he said that the mitigating evidence that he had used in the past was evidence of something that had an impact on the defendant’s mind at the time. App. at 1874. It is not apparent that mental health evidence is likely to be persuasive for mitigation purposes if it cannot have had any impact on a murderer’s mind at the time of offense.
Third and most important, even assuming for the sake of argument that Dr. Sadoffs understanding of the range of mental health evidence that can be mitigating was unduly narrow, we see absolutely no reason to believe that Dr. Sa-doffs understanding contributed in any way to his failure to detect the conditions that Rompilla now claims. Rompilla argues that he “suffers from organic brain damage, including damage to the frontal lobes and parietal area” and that these impairments, among other things, prevent him from “adequately controlling] and guid[ing] his behavior,” “emotions,” and “impulses.” Rompilla Br. at 58. He argues that these conditions “substantially impair[] his capacity to appreciate criminality of conduct or conform conduct to the requirements of law.” Id. at 96. Accordingly, these impairments surely would have “impacted” his mind at the time of the Scanlon murder and thus fall squarely *256within the scope of the sort of mitigating evidence to which Dr. Sadoff referred.
Rompilla argues that his trial attorneys were ineffective because they did not ask Dr. Gross to look for mitigating evidence. Rompilla Br. at 65 (citing App. 1535-36, 1545). However, Drs. Cooke and Sadoff did look specifically for mitigating evidence, and the scope of Dr. Gross’s evaluation encompassed at least some mitigating evidence. He stated: “I was looking to see if he knew what he was doing, whether he was suffering from any kind of psychiatric disorder, whether he may have been intoxicated, exactly what his emotions and cognitive processes were.” App. 1506. In light of what Drs. Cooke and Sadoff were asked to do and in fact did, trial counsel’s instructions to Dr. Gross do not show that trial counsel were ineffective.
Finally, Rompilla argues that trial counsel were ineffective in failing to do further investigation relating to Rompilla’s alcohol use. Rompilla never explains exactly what alcohol-related mitigation argument he believes his trial attorneys should have made, but he refers to information suggesting that there is a history of alcohol-abuse in the Rompilla family, that he is an alcoholic, that his alcoholism was caused by his traumatic childhood, that he suffers from alcohol-induced blackouts, and that he was intoxicated on the night of the murder. While these elements can be woven into an attractive mitigation argument, most of the elements are based on information in the records that trial counsel was not, for the reasons we have explained, constitutionally obligated to obtain. This includes evidence of drinking in the Rompilla family, Rompilla’s abusive childhood home, blackouts, and Rompilla’s alcoholism.
The only alcohol-related mitigation argument that trial counsel could have made without obtaining the previously discussed records — namely, that Rompilla was so intoxicated at the time of the Scanlon murder that his judgment was impaired— would not have been particularly compelling. Moreover, while evidence to support this argument was available,13 the argument would have to have been made without the support of testimony from Rompil-la, who did not take the stand at either phase of the trial and denied intoxication or alcohol problems. We cannot say that it was objectively unreasonable for trial counsel not to put on such a defense.
Finally, Rompilla argues that the Supreme Court’s recent decision in Wiggins v. Smith, — U.S. —, 123 S.Ct. 2527, 156 L.Ed.2d 471 (2003), shows that his trial attorneys conducted an unreasonably abbreviated investigation of potential mitigating factors, but there is a sharp contrast between the conduct of the attorneys in Wiggins and those in this case. In Wiggins, the trial attorneys claimed that they made a tactical decision not to present mitigating evidence but instead to pursue the alternative strategy of attempting to prove that someone other than the defendant actually killed the victim. Id. at 2533. Accordingly, they made little effort to investigate the defendant’s background although they had reason to believe that such an investigation would have been fruitful.
The Supreme Court found that defense counsel’s investigation of their client’s background was based entirely on the pre-sentence investigation report (PSI) and documents from the Baltimore City Department of Social Services (DSS). Id. at 2540. Although funds were available for *257the preparation of a social history of the defendant, counsel did not commission such a report. Id. at 2536. But even the limited documents that counsel reviewed contained information that should have alerted counsel that an expanded investigation into their client’s background was likely to yield mitigation evidence. The PSI reported that the defendant had spent most of his childhood in foster care and quoted the defendant as describing his background as “disgusting.” Id. at 2536. The DSS records disclosed that the defendant’s “mother was a chronic alcoholic; Wiggins was shuttled from foster home to foster home and displayed some emotional difficulties while there; he had frequent, lengthy absences from school; and, on at least one occasion, his mother left him and his siblings alone for days without food.” Id. at 2537.
Wiggins’s trial counsel nevertheless failed to follow these leads. Counsel moved for bifurcation of the penalty phase trial so that they could first attempt to show that them client did not kill the victim by his own hand and then, if that defense was rejected, offer evidence in mitigation. Id. at 2532. When bifurcation was denied, defense counsel made a brief reference in her penalty phase opening to the defendant’s “difficult life” but “introduced no evidence of [his] life history.” Id. And although counsel proffered some evidence that would have been introduced if the bifurcation had been allowed, no evidence of the defendant’s life history or family background was included. Id. After the defendant was sentenced to death, new counsel commissioned the preparation of a social history. Id. at 2532. A social worker interviewed Wiggins and family members, obtained additional documents, and compiled evidence of severe physical and sexual abuse by Wiggins’s mother. Id. at 2532, 2542.
Faced with these facts, the Supreme Court held that it was objectively unreasonable for counsel not to conduct a further investigation for mitigating evidence regarding Wiggins’s background. Id. at 2541. The Court stated that “any reasonably competent attorney” would have realized that it was necessary to follow the leads in the PSI and DSS documents before making a choice among potential defenses. Id. at 2537. The Court stressed that “counsel uncovered no evidence in their investigation to suggest that ... further investigation would have been fruitless.” Id. The Court also.emphasized that Strickland does not require counsel to investigate every conceivable line of mitigating evidence no matter how unlikely the effort would be to assist the defendant at sentencing. Id. Instead, the Court reiterated that “[a] decision not to investigate ... ‘must be directly assessed for reasonableness in all the circumstances.’ ” Id. (quoting Strickland, 466 U.S. at 691, 104 S.Ct. 2052).
There are critical differences between the conduct of Wiggins’s and Rompilla’s trial attorneys. Wiggins’s attorneys were presented with leads that “any reasonably competent attorney” would have realized were promising. Rompilla’s attorneys had no comparable leads. Wiggins described his childhood as “disgusting”; Rompilla insisted that his was “normal.” In Wiggins, postconviction interviews with Wiggins himself and with members of his family produced evidence of severe abuse. 123 S.Ct. at 2542. In the present case, Rom-pilla’s attorneys interviewed their client and numerous family members in detail before the penalty proceeding but discovered no mitigating evidence. Wiggins’s attorneys “uncovered no evidence in their investigation to suggest that ... further investigation would have been fruitless.” Id. at 2537. Rompilla’s trial attorneys had a body of evidence that suggested that a *258further investigation into Rompilla’s family background would not have been productive. Not only did Rompilla’s attorneys probe their client for mitigating evidence, but they interviewed numerous members of his family, including siblings who bracketed him in age. At least one of these siblings, Nicholas Rompilla, later revealed that he knew about the conditions in the home on which Rompilla now relies, but he never provided that information to trial counsel, and although he now claims that trial counsel never asked him about any period of time other than the months immediately preceding the murder, the PCRA court found that this testimony was not believable.
In short, the attorneys in Wiggins did little to investigate their client’s background although they possessed information that should have prompted them to do so. Rompilla’s attorneys conducted a much greater investigation, but their interviews with their client and his family provided a reasonable basis for concluding that additional investigation would not have represented a wise allocation of limited resources. In our view, Wiggins is critically different from the present case.
Rompilla asserts that Dr. Gross’s report “explicitly recommend[ed] that counsel investigate alcoholism,” Rompilla Br. at 66, but this is not exactly what Dr. Gross wrote. Dr. Gross said that “[t]he possibility does remain ... that Mr. Rompilla while under the influence of alcohol, can become prone to violent behavior although he himself strongly denies this.” Dr. Gross added: “My recommendation is that this area should be further evaluated before any definitive conclusions are drawn.” (emphasis added). Thus, Dr. Gross did not say that further evaluation was likely to produce evidence that Rom-pilla becomes violent when drunk, only that this was a “possibility.” Nor did he recommend further evaluation as a promising strategy for the defense. Instead, he merely said that “no definitive conclusions” should be drawn about this possibility unless there was a further evaluation. And finally, it should be noted that he referred to a further “evaluation” (a term that suggests a psychiatric examination), not an “investigation.” Rompilla’s brief repeatedly uses the term “investigate” in an apparent attempt to suggest that Dr. Gross recommended that trial counsel search for evidence such as the records discussed above. The use of this term obscures the fact that trial counsel did precisely what Dr. Gross recommended: they had Rom-pilla “evaluated” further, i.e., examined by another psychiatrist, Dr. Sadoff.
In conclusion, it appears to us that Rom-pilla is now arguing that his trial counsel were constitutionally derelict in failing to take all the steps that might have been pursued by the most resourceful defense attorneys with bountiful investigative support. But while we may hope for the day when every criminal defendant receives that level of representation, that is more than the Sixth Amendment demands. See Strickland, 466 U.S. at 689, 104 S.Ct. 2052 (“the purpose of the effective assistance guarantee of the Sixth Amendment is not to improve the quality of legal representation, although that is a goal of considerable importance to the legal system”); Burger, 483 U.S. at 794, 107 S.Ct. 3114 (“The record at the habeas corpus hearing does suggest that [counsel] could well have made a more thorough investigation than he did. Nevertheless, in considering claims of ineffective assistance of counsel, ‘[w]e address not what is prudent or appropriate, but only what is constitutionally compelled.’ ”) (quoting Cronic, 466 U.S. at 665 n. 38, 104 S.Ct. 2039) (alteration in original). The Sixth Amendment is satisfied when “counsel’s conduct falls within the wide range of reasonable professional assistance,” thereby “ensuring] that crimi*259nal defendants receive a fair trial.” Strickland, 466 U.S. at 689, 104 S.Ct. 2052.14 See also Waters, 46 F.3d at 1512 (“The test has nothing to do with what the best lawyers would have done. Nor is the test even what most good lawyers would have done.... We are not interested in grading lawyers’ performances; we are interested in whether the adversarial process at trial, in fact, worked adequately.”) (quoting White v. Singletary, 972 F.2d 1218, 1220-21 (11th Cir.1992)). Here, the state court’s determination that counsel acted reasonably was not “contrary to” or an “unreasonable application” of Strickland.
VII.
Rompilla advances three claims related to the trial court’s response to the jury’s questions about accomplice liability. First, Rompilla argues that his federal constitutional right to due process was violated because the court instructed the jury on accomplice liability without providing “notice or fair warning that he might be subjected to liability as an accomplice.” Rom-pilla Br. at 14. Second, he contends that his federal constitutional right to due process was abridged because the accomplice-liability comments did not state that “accomplice liability must be proven beyond a reasonable doubt and that conviction for murder, even based on accomplice liability, required proof of a specific intent to kill.” Id. at 20. Third, he maintains that his rights under the Sixth, Eighth, and Fourteenth Amendments were violated because the trial judge’s remarks prevented the jury “from considering and giving exculpatory and mitigating effect to evidence that someone other than Rompilla was the killer.” Id. at 22 (emphasis in original removed).
A.
Under 28 U.S.C. § 2254(b)(1), a state prisoner’s application for a writ of *260habeas corpus “shall not be granted unless it appears that ... the applicant has exhausted the remedies available in the courts of the State” or the case falls within one of two exceptions to the exhaustion requirement, i.e., “there is an absence of available State corrective process” or “circumstances exist that render such process ineffective to protect the rights of the applicant.” Moreover, under 28 U.S.C. § 2254(b)(3), a state may not be deemed to have waived exhaustion or be estopped from relying on exhaustion “unless the State, through counsel, expressly waives the requirement.” In order to exhaust state remedies, a habeas petitioner must present the petitioner’s federal claim in the state courts. See Keller v. Larkins, 251 F.3d 408, 413 (3d Cir.2001). It is not enough for a petitioner to advance a similar state-law claim. Duncan v. Henry, 513 U.S. 364, 366, 115 S.Ct. 887, 130 L.Ed.2d 865 (1995). Rather, a petitioner must “present a federal claim’s factual and legal substance to the state courts in a manner that puts them on notice that a federal claim is being asserted.” McCandless v. Vaughn, 172 F.3d 255, 261 (3d Cir.1999).
Three sections of Rompilla’s brief on direct appeal to the state supreme court raised claims concerning the accomplice liability instruction. First, Rompilla argued that the judge erred in giving the instruction because the defense had no prior notice that this theory of liability was in the case and because the judge refused a defense request that “the jury be specifically instructed that under an accomplice theory every element must be proven beyond a reasonable doubt.” Appellant’s Br. at 11, Commomvealth v. Rompilla, Supreme Court of Pennsylvania, Philadelphia District, No. 53 Capital Appeal Docket (hereinafter “Rompilla Direct Appeal Br.”). Although this section of Rompilla’s brief did refer to the requirement of proof beyond a reasonable doubt — something demanded by both the federal Constitution and Pennsylvania law15 — the brief made no reference to the federal Constitution and did not cite any federal authorities. Second, Rompilla argued that the judge erred in refusing to poll the jury as to whether the guilty verdict was based on the theory of accomplice liability. Rompil-la Direct Appeal Br. at 15-17. This contention was based exclusively on state law. Third, Rompilla repeated the argument that the trial judge erred in refusing to give the requested defense instruction to the effect that conviction as an accomplice required proof beyond a reasonable doubt. Id. at 17-18. Only state authorities grounded on state law were cited.
Based on our examination of Rompilla’s brief to the Pennsylvania Supreme Court, it is not clear that Rompilla properly presented any federal constitutional claim to that court.16 Moreover, even if Rompilla’s brief to the state supreme court is read as having raised the federal claim that the trial judge erred in refusing to give the requested instruction on the requirement of proof beyond a reasonable doubt, it seems clear that the remaining federal constitutional claims advanced by Rompilla in this appeal were not presented to the state supreme court. Rompilla’s argument in the state supreme court concerning the lack of prior notice was based solely on state authorities, and the argument that Rompilla has made to us that the trial *261judge’s instruction effectively prevented the jury from considering exculpatory and mitigating evidence was never made, either as a state- or federal-law claim, in Rompilla’s direct appeal brief.
In view of these deficiencies, if Rompilla could still return to the state courts and present the federal constitutional claims that he has made here, we would probably be obligated to regard those claims as unexhausted. It is clear, however, that Rompilla can no longer raise those claims in state court, 42 Pa. Cons.Stat. Ann. § 9545(b), and therefore it appears that those claims are exhausted but are probably procedurally defaulted. See Fahy v. Horn, 240 F.3d 239, 245 (3d Cir.2001). The Commonwealth has not raised the defense of procedural default, but we have the discretion to do so in appropriate circumstances. See Sweger v. Chesney, 294 F.3d 506, 520 (3d Cir.2002) cert. denied, — U.S. —, 123 S.Ct. 1902, 155 L.Ed.2d 830 (2003). Nevertheless, we do not rely on the doctrine of procedural default in deciding this appeal. Assuming for the sake of argument that our consideration of those claims on the merits is not barred, we find that the claims do not provide a basis for habeas relief.
B.
When language in jury instructions is challenged, the language in question “must be considered in the context of the instructions as a whole and the trial record.” Estelle v. McGuire, 502 U.S. 62, 72, 112 S.Ct. 475, 116 L.Ed.2d 385 (1991). We then consider “ ‘whether there is a reasonable likelihood that the jury has applied the challenged instructions in a way’ that violates the Constitution.” Smith v. Horn, 120 F.3d 400, 411 (3d Cir.1997) (quoting McGuire, 502 U.S. at 72, 112 S.Ct. 475.) Under these standards, the trial judge’s comments about accomplice liability did not violate Rompilla’s constitutional rights.
1.
Since there were no eyewitnesses to the killing, the Commonwealth’s case was based almost entirely on the previously noted circumstantial evidence. See Rompilla-1, 653 A.2d at 629. The defense argued that someone other than Rompilla was the actual assailant.
During jury deliberations in the guilt phase, the jury asked:
If Defendant was an accomplice to the Charge of Criminal Homicide, can he be charged with Murder in the First Degree?
App. at 585. In response, the trial judge began by informing the jury that the Commonwealth had not proceeded on the theory that Rompilla was liable for the murder as an accomplice and that no instruction on accomplice liability had been given. The judge stated:
Well, preliminarily, let me say this. If you recall, the Court, in [its] Charge, at no time referred to any theory of accomplice in this case. It is not the Commonwealth’s theory in this case that the Defendant was an accomplice. I’m not quite sure what prompted the question. If it arose because of something that was argued by Counsel in the closing speeches, if you recall, I indicated that you are to give — and you should be guided by each Lawyer’s arguments to the extent they’re supported by the evidence and in so far as they aid you in applying your own reason and common sense. However, you are not required to accept the arguments of either Lawyer. It is for you alone — you and you alone to decide this case based on the evidence as it was presented from this witness stand and in accordance *262with the instruction which the Court gave you. Now, again, as I say, I’m not quite sure what prompted the question, but you did ask the question, and I assume you want an answer, is that correct?
Id. at 585-86 (emphasis added). The jury foreman nodded in the affirmative, and the trial court then attempted to explain when an accomplice could be held liable for a crime committed by another. Id. at 586-87. The court concluded, however, with the following comments:
I can only say this to you, that you should determine this case based on the Charge of the Court as it had given you originally. There was no evidence in this case with regard to the question as posed but a simple clear answer to the question is yes, you could be charged with, and you could be convicted of Murder in the First Degree if, indeed, you’re an accomplice, but it requires other proof or findings on your part that were not a part of this case nor were they made a part of this case, all right.
Id. at 587-88 (emphasis added).
On direct appeal, the state supreme court did not decide whether the trial judge’s comments about accomplice liability were flawed but instead held that any error was cured by the judge’s admonition to the jury that it should not consider that theory of liability. Id.17 The District Court — presented with arguments notably different from those advanced in the state supreme court — went beyond the state supreme court in holding that the judge’s explanation of accomplice liability was incomplete, but the District Court agreed with the state supreme court that any flaw was cured by the trial court’s admonition that the theory of accomplice liability was not before the jury in this case. Rompilla, 2000 WL 964750, at *14. Similarly, we conclude that, even assuming arguendo that the challenged comments were constitutionally flawed, there is no basis for ha-beas relief. The state supreme court’s decision that any defect in the challenged comments was cured by the judge’s admonition that the jury was not to consider the theory of accomplice liability did not “involve an unreasonable application of Federal law,” 28 U.S.C. § 2254(d)(1), namely, the rule that jury instructions do not violate the Constitution unless there is a reasonable probability that they were applied in a way that abridged constitutional rights. Moreover, even under a standard of plenary review, we would find no constitutional violation.
Here, the clear thrust of the trial court’s response to the jury’s question was that the Commonwealth was not relying on the theory that Rompilla was liable as an accomplice and that the jury should not consider that theory as a possible basis for conviction. As noted, when the judge first responded to the jury’s question, the judge began by reminding the jury that the court’s instructions “at no time referred to any theory of accomplice in this case. It is not the Commonwealth’s theory in this case that the Defendant was an accomplice.” App. 585-86. In addition, the judge told that jury that they were required to decide the case “in accordance *263with the instruction which the Court gave you.” Id. Since “the instruction which the Court gave [the jury]” “at no time referred to any theory of accomplice in this case,” id. at 585-86, the judge’s comments meant that the jury was to decide the case without relying on the theory of accomplice liability. The judge’s final statements regarding accomplice liability made exactly the same point. The judge stated: “I' can only say this to you, that you should determine this case based on the Charge of the Court as it had given you originally.” Id. at 587. Jurors are presumed to follow the court’s instructions. Richardson v. Marsh, 481 U.S. 200, 211, 107 S.Ct. 1702, 95 L.Ed.2d 176 (1987). In view of the instructions given here, it is not reasonably likely that the jury interpreted the judge’s comments to mean anything other than that they were not to consider accomplice liability as a possible ground for conviction.
Once the meaning of the judge’s comments is understood, it is apparent that there is no merit in Rompilla’s argument that his right to due process was violated because he did receive prior notice that he might be subjected to liability as an accomplice or in his argument that the judge’s explanation of accomplice liability was constitutionally flawed. Since the trial judge told the jury that it was to decide the case without relying on the theory of accomplice liability, these arguments fail.
Rompilla contends that the trial court told the jury that it should not consider accomplice liability because no evidence was presented during the trial to support such a finding. Rompilla Br. at 16. Rom-pilla then maintains that the trial judge gave contradictory instructions in that, on the one hand, he told the jury not to consider accomplice liability because there was no evidence to support such a finding and, on the other hand, he told the jury that it was the sole factfinder and its recollection of the evidence should therefore control. According to Rompilla, the jury was left with two irreconcilable options— either to disregard the theory of accomplice liability because the trial court believed there was no evidence to support the theory or to consider the theory if the jury, as sole factfinder, believed, as suggested by its question, that there was evidence of an accomplice.
This elaborate argument rests on the faulty premise that the trial judge instructed the jury that the reason why the theory of accomplice liability was not in the case was because there was no supporting evidence. In fact, however, the judge never made such a statement. The trial judge did state that “[t]here was no evidence in this case with regard to the question as posed,” but he did not state that this was why the theory was not in the case. Rather, as noted, the judge twice told the jury that they were not to consider accomplice liability because it was not in the original charge, and the judge also noted that “[i]t [was] not the Commonwealth’s theory in this case that the Defendant was an accomplice.”
Rompilla’s remaining argument (that the trial judge’s statements prevented the jury from considering exculpatory and mitigating evidence) entirely misconstrues the judge’s words. The judge did not, as Rompilla contends, say that there was no evidence that another person was involved. Rather, the judge stated that “[t]here was no evidence in this case with regard to the question as posed.” The “question as posed” was: “If Defendant was an accomplice to the Charge of Criminal Homicide, can he be charged with Murder in the First Degree?” Thus, the judge essentially said that there was no evidence to support a conviction under an accomplice liability theory; the judge did not say that there-was no evidence that might justify *264reasonable doubt, or residual doubt for purposes of sentencing mitigation, as to whether Rompilla committed the killing with the requisite intent. Accordingly, nothing that the judge said foreclosed consideration of exculpatory or mitigating evidence.
In sum, after considering all of Rompil-la’s arguments regarding accomplice liability, we see no ground for habeas relief.
VIII.
Rompilla contends, finally, that his future dangerousness was put at issue during the sentencing phase of his trial and that therefore, under Simmons v. South Carolina, 512 U.S. 154, 114 S.Ct. 2187, 129 L.Ed.2d 133 (1994), the trial court was required to inform the jury that “life” imprisonment under Pennsylvania law means “life without parole.” We agree with the District Court, however, that the Pennsylvania Supreme Court’s rejection of this claim cannot be disturbed under the narrow standard of review prescribed by AEDPA.
A.
Rompilla maintains that the state supreme court’s decision was “contrary to” and represented “an unreasonable application” of Simmons.18' The actual holding in Simmons, however, as set out in Justice O’Connor’s controlling opinion, is narrower than Rompilla acknowledges.
In Simmons, the defendant was convicted of capital murder for the killing of an elderly woman. Simmons, 512 U.S. at 156, 114 S.Ct. 2187. The defendant had a history of assaulting elderly women, and both defense and state witnesses agreed that the defendant posed a continuing danger to elderly women. Id. at 157, 114 S.Ct. 2187. During the penalty phase, the state argued that the question for the jury was “what to do with [the defendant] now that he is in our midst.” Id. The state also urged that a death sentence would be “a response of society to someone who is a threat. Your verdict will be an act of self-defense.” Id. The defendant sought to rebut the state’s argument by presenting evidence that his dangerousness was limited to elderly women and that there was no reason to expect acts of violence once he was in a prison setting. Id. The trial court denied defense counsel’s request for a parole ineligibility instruction. Id. at 158-60, 114 S.Ct. 2187. During deliberations, the jury asked if a life sentence included the possibility of parole. Id. at 160, 114 S.Ct. 2187. -The trial court instructed the jury not to consider parole or parole eligibility and told the jury that life imprisonment and death were to be understood in their plain and ordinary meaning. Id. Shortly thereafter, the jury returned with a sentence of death. Id.
The United States Supreme Court held that, under these circumstances, due process required the trial judge to inform the jury that the defendant would not have been eligible for parole if sentenced to imprisonment for. life. The plurality opinion endorsed by four Justices reasoned that
the jury reasonably may have believed that petitioner could be released on parole if he were not executed. To the extent this misunderstanding pervaded the jury’s deliberations, it had the effect of creating a false choice between sentencing petitioner to death and sentencing him to a limited period of incarceration. This grievous *265misperception was encouraged by the trial court’s refusal to provide the jury with accurate information regarding petitioner’s parole ineligibility, and by the State’s repeated suggestion that petitioner woidd pose a future danger to society if he were not executed.
Id. at 161-62, 114 S.Ct. 2187 (plurali-tyXemphasis added). The plurality found that the jury was then “left to speculate about ... parole eligibility when evaluating petitioner’s future dangerousness, and was denied a straight answer ... even when it was requested.” Id. at 165-66, 114 S.Ct. 2187. Consequently, the plurality stated that “where the defendant’s future dangerousness is at issue, and state law prohibits the defendant’s release on parole, due process requires that the sentencing jury be informed that the defendant is parole ineligible.” 512 U.S. at 156, 114 S.Ct. 2187 (plurality)(emphasis added). Id. at 161-62, 114 S.Ct. 2187.19
The controlling opinion in Simmons— Justice O’Connor’s concurrence in the judgment, in which the Chief Justice and Justice Kennedy joined — seemed to phrase the holding more narrowly. Justice O’Connor stated that a “defendant should be allowed to bring his parole ineligibility to the jury’s attention ... in cases in which the only available alternative sentence to death is life imprisonment without possibility of parole and the prosecution argues that the defendant will pose a threat to society in the future.” Id. at 177, 114 S.Ct. 2187 (O’Connor, J., concurring in the judgement) (emphasis added). Other passages in Justice O’Connor’s opinion pointed in the same direction. She referred to cases “ ‘[wjhere the prosecution specifically relies on a prediction of future dangerousness in asking for the death penalty,’ ” id. at 175, 114 S.Ct. 2187 (emphasis added) (citation omitted)(brackets in original) and cases where “the State seeks to show the defendant’s future dangerousness.” Id. at 177, 114 S.Ct. 2187. See also id. at 176, 114 S.Ct. 2187 (“the State sought to show that petitioner is a vicious predator who would pose a continuing threat to the community”); id. at 177, 114 S.Ct. 2187 (“The prosecutor in this case put petitioner’s future dangerousness in issue”).
In short, whereas the Simmons plurality opinion may be read to state that the Simmons rule applies whenever a defendant’s future dangerousness is “at issue” (whether or not the prosecution makes that argument), Justice O’Connor’s controlling opinion may be read more narrowly to hold that the rule governs only where the prosecution actually “argue[s]” that a defendant poses a future threat. Neither position, of course, has perfectly clear boundaries. There is a sense in which future dangerousness is “at issue” at the penalty phase of virtually all capital cases. The possibility that a first-degree murderer will kill again is likely to be present in the jurors’ mind in all cases except those where the defendant committed the murder for which he or she was convicted only because of unusual circumstances that are very unlikely to occur again even if the defendant is released from prison. As the Chief Justice has put it, “[i]t is difficult to envision a capital sentencing hearing where the State presents no evidence from which a juror might make [an inference of *266future dangerousness to society].” Kelly v. South Carolina, 534 U.S. 246, 122 S.Ct. 726, 735, 151 L.Ed.2 d 670 (2002)(Rehn-quist, C.J., dissenting). Thus, read liberally, the plurality’s position in Simmons would mandate that the jury be informed about parole ineligibility in almost all capital cases in which the only possible sentences are death or life without parole.
On the other hand, the fine line that Justice O’Connor’s opinion seemed to draw — between cases in which the prosecution “argue[s]” future dangerousness and cases in which future dangerousness is inferred by the jury from the evidence that is brought to its attention' — is difficult to police and arguably superficial. A prosecutor may encourage a jury to think about future dangerousness without expressly referring to that concept.
Last year, in Kelly v. South Carolina, 534 U.S. 246, 122 S.Ct. 726, 151 L.Ed.2d 670 (2002),20 the Court arguably broadened the holding in Simmons. In Kelly, the state told the jurors in its opening at the penalty phase: “I hope you never in your lives again have to experience what you are experiencing right now. Being some thirty feet away from such a person. Murderer.” Kelly, 122 S.Ct. at 729. The state then presented evidence that while in prison, Kelly had made a knife, had attempted to escape from prison, and had planned to hold a female guard as a hostage. Id. The state also brought out evidence of “Kelly’s sadism at an early age, and his inclination to kill anyone who rubbed him the wrong way.” Id. (citation omitted). During closing arguments, the state referred to Kelly as “the butcher of Batesburg,” “Bloody Billy,” and “Billy the Kid.” Id. The state also told the jurors that “Kelly doesn’t have any mental illness. He’s intelligent ... He’s quick-witted. Doesn’t that make somebody a little more dangerous .... for this lady ... doesn’t that make him more unpredictable for [the victim] .... murderers will be murderers. And he is the cold-blooded one right over there.” Id. at 729-30. The trial court did not give a parole ineligibility instruction. Id. at 730.
The Supreme Court held that Kelly’s future dangerousness was sufficiently put at issue that he was entitled to a parole ineligibility instruction. Id. at 731, 733-34. In the body of its opinion, the Court stated that “[e]vidence of future dangerousness under Simmons is evidence with a tendency to prove dangerousness in the future; its relevance to that point does not disappear merely because it might support other inferences or be described in other terms.” Id. at 732. The Court recognized that “it may well be that the evidence in a substantial proportion, if not all, capital cases will show a defendant likely to be dangerous in the future,” but the Court declined to address the issue of whether a defendant is entitled to a parole ineligibility instruction when the state’s evidence shows future dangerousness but the prosecutor does not argue it. Id. at 732 n. 4. The Court concluded that “[t]he prosecutor accentuated the clear inference of future dangerousness raised by the evidence and placed the case within the four corners of Simmons. ” Id. at 732.
The Kelly dissenters, including two of the Justices who had joined Justice O’Con-nor’s opinion in Simmons, argued that the Court had improperly extended Simmons’ s reach. See id. at 735 (Rehnquist, C.J., joined by Kennedy, J., dissenting) (“the test is no longer whether the State argues *267future dangerousness to society[,] [as the Court found in Simmons ]; the test is now whether evidence was introduced at trial that raises an ‘implication’ of future dangerousness to society”) and id. at 737 (Thomas, J., joined by Sealia, J., dissenting) (“the Court dilutes the Simmons test, now requiring that a parole ineligibility instruction be given where the prosecution makes arguments that have a ‘tendency to prove dangerousness in the future.’ ”).
Even if Kelly broadened Simmons, however, Kelly cannot aid Rompilla here. Under 28 U.S.C. § 2254(d)(1), our review is limited to deciding whether a state court decision is “contrary to” or an “unreasonable application” of Supreme Court precedent “as of the time of the relevant state-court decision.” Williams, 529 U.S. at 412, 120 S.Ct. 1495 (emphasis added). The state court decisions in this case preceded Kelly. Accordingly, regardless of whether Kelly expands the circumstances when future dangerousness is at issue for purposes of requiring a parole ineligibility instruction, the case is not applicable to the instant matter. We are limited to deciding whether the state court decisions in this case were contrary to or an unreasonable application of the holding in Simmons itself — which is to say Justice O’Connor’s controlling concurrence. We must thus determine whether the Pennsylvania Supreme Court was reasonable in concluding that the prosecutor in the present case did not “argue[ ]” that Rompilla would present a future danger if not sentenced to death. We therefore turn to the relevant events at the penalty phase of Rompilla’s trial.
B.
During the penalty phase, the Commonwealth attempted to establish the aggravating factor that Rompilla had a “significant history of felony convictions” as specified in 428 Pa.C.S. § 9711(d)(9). In doing this, the Commonwealth read into the record the testimony of J.M., a female bar owner whom Rompilla had previously robbed, slashed with a knife, and raped. During closing arguments, the Commonwealth argued:
[T]he woman that was raped, was raped pretty brutally. She was raped at knife point.... [Ijsn’t it frightening, the similarity between that case and this case. I mean, it is absolutely astounding. Both take place around the bar. The Defendant gets in after closing or right before closing.... On both occasions, a knife was used. Steals money both times. Isn’t it frightening the similarities in those crimes. Takes a taxi away from [J.M.’s] Bar, takes a taxi the night of this crime. He slashes [J.M.] in the breast with a knife. He uses a knife on Jimmy Scanlon. It’s absolutely frightening to think of the similarities in those two crimes. But there is one difference, one major difference, [J.M.] lived through her experience. Jimmy Scanlon didn’t.... I keep wondering, why did the Defendant wait till Jimmy Scanlon left the Bar? He knew he was closing up. Why didn’t he just wait until he had left to break in and steal the money, no problem, nobody gets hurt? You have to ask yourselves, why didn’t he wait for Jimmy Scanlon to leave? Was it his intent to kill right from the start? Was it his intent to do serious bodily injury right from the start? Because if he had waited maybe a half hour, an hour later, Jimmy Scanlon would have been gone. This wouldn’t be a homicide case. Jimmy Scanlon would still be living. I think the Defendant learned a lesson from [J.M.] in that case, that Rape case. That lesson was, don’t leave any witnesses. Don’t *268leave anybody behind that can testify against you.
App. at 779-80.
During deliberations the jury asked:
If a life sentence is imposed, is there any possibility of the Defendant ever being paroled?
Id. at 802. The trial judge answered:
I’m sorry to say, I can’t answer that question. That’s not before you as such. The only matter that you can consider in the Sentencing Hearing is the evidence that was brought out in the course of the Hearing and the Law with respect to the Court’s Charge. That’s the only consideration you have, I’m sorry to say. I — if there were other alternatives that you should consider, we would have outlined them in the Charge, all right.
Id. at 802-03.
Several hours later, the jury asked to see the docket entries for Rompilla’s prior convictions for the purpose of ascertaining Rompilla’s prior sentence. The judge denied the request, and the following exchange took place:
Juror No. 3: ... we want to know if it was — the sentence was — if he got released on behavioral—
Foreman: It was commuted in any way, the original sentence.
Court: Well, that we can’t give you.
Prosecutor: You can’t tell them.
Id. at 823-24.
The next day, after two more hours of deliberation, the jury asked:
Was the Defendant offered any type of rehabilitation either while in prison or after his release from prison?
Id. at 842. The following colloquy then occurred:
Court: Well, I’m sorry to say, I can’t answer that. I can only tell you that you’re going to have to make your decision based upon the evidence that was presented and in accordance with the Law with respect to Sentencing Hearing. First of all, I couldn’t even answer it if I wanted to or if I could, I don’t know.
Foreman: Could I change the question to the point that is — isn’t rehabilitation available in prison?
Court: Well, again, I would like to even answer that, and I can’t. You’re going to have to rely upon your own knowledge of that aspect if, indeed, that is a part that troubles the area that you’re interested in. The penology system, I’ll be quite frank with you, is not an issue before — before you with respect to the Law that it’s a decision that you must make. I can understand your interest, however, as I say, we’re constrained to, you know, comply with whatever evidence that was put on in the hearing and then your decision must be based upon whatever the Law says and whatever you may find. All right.
Id. at 842-43. Three hours later the jury returned a sentence of death.
The PCRA court found that Simmons did not apply because the prosecutor did not argue future dangerousness. App. at 2025. The District Court similarly found that a “fair reading of [the prosecutor’s summation] leads to the conclusion that the state’s reasoning for the death penalty was not based upon future dangerousness,” but rather upon Rompilla’s “despicable, savage and cowardly beating” of the victim. Rompilla, 2000 WL 964750, at *15. The District Court concluded that although a “close issue,” the state supreme court’s decision was not an unreasonable application of federal law. Id.
*269c.
As noted, Rompilla relies on both the “contrary to” and “unreasonable application” prongs of 28 U.S.C. § 2254(d)(1). We will discuss each prong separately.
1.
A result is “contrary to” a Supreme Court holding if the state court “contradicts the governing law set forth in [the Supreme Court’s] cases” or if it “confronts a set of facts that are materially indistinguishable from a decision of [the Supreme] Court and nevertheless arrives at a [different] result.” Id. at 405-06, 120 S.Ct. 1495. Williams v. Taylor, 529 U.S. 362, 412, 120 S.Ct. 1495, 146 L.Ed.2d 389 (2000). This prong is not met here because the Pennsylvania Supreme Court applied the holding of Simmons and because the facts of Simmons and the present case are materially distinguishable.
Rompilla argues that the state supreme court’s decision is “contrary to” Simmons because the state supreme court did not inquire whether there was “a ‘reasonable likelihood’ that parole and future dangerousness affected the sentencing decision.” Rompilla Br. at 42 (citing Simmons, 512 U.S. at 170, 114 S.Ct. 2187). We reject this argument. Neither the Simmons plurality nor Justice O’Connor’s concurrence stated that the test for entitlement to an instruction on parole ineligibility hinges on whether there is a reasonable likelihood that future dangerous might figure in the jury’s verdict. Rather, the Simmons plurality opinion referred to the concept of “reasonable likelihood” in considering a different question — whether, once future dangerousness was put at issue, there was a “reasonable likelihood” that a jury instruction “directing juries that life imprisonment should be understood in its ‘plain and ordinary’ meaning” dispelled any misunderstanding that the jurors might have had as to the meaning of life imprisonment. Simmons, 512 U.S. at 169-70, 114 S.Ct. 2187 (citing Boyde v. California, 494 U.S. 370, 380, 110 S.Ct. 1190, 108 L.Ed.2d 316 (1990)).
Rompilla contends that the prosecution necessarily put his future dangerousness at issue by presenting evidence of his prior criminal conduct to establish the aggravating factor that he had a significant history of felony convictions. According to Rom-pilla, the state supreme court rendered a decision that was “contrary to” Skipper v. South Carolina, 476 U.S. 1, 106 S.Ct. 1669, 90 L.Ed.2d 1 (1986) and Ramdass v. Ange-lone, 530 U.S. 156, 120 S.Ct. 2113, 147 L.Ed.2d 125 (2000), when it rejected this argument on the “formalistic” ground that this aggravator concerns past conduct rather than future behavior. Rompilla Br. at 42. This argument is also meritless. It overlooks the scope of Justice O’Connor’s Simmons concurrence, which, as noted, can reasonably be read as focusing on the prosecution’s arguments, not the inferences that arise from the facts that are proven. On this view, proving past crimes that may cause jurors to worry about future dangerousness is quite different from arguing that a defendant presents a future threat.
In addition, Skipper does not hold or even state that proving prior felony convictions is tantamount to arguing that a defendant presents a future threat for Simmons purposes. In Skipper, the Court held that the capital defendant’s right to present all relevant mitigating evidence at the sentencing stage of the trial was violated by the state court’s refusal to admit evidence that the defendant had made a good adjustment to jail during the time between his arrest and the trial. Thus, Skipper had nothing to do with an instruc*270tion on parole ineligibility.21
Rompilla’s reliance on Ramdass is also misplaced. Not only does Ramdass postdate the decision of the Pennsylvania Supreme Court, but Ramdass does not address the question of when future dangerousness is sufficiently put in issue to require an instruction on parole ineligibility. In Ramdass, the prosecution expressly argued future dangerousness as an aggravating circumstance, and thus that point was not disputed. Ramdass, 530 U.S. at 161, 120 S.Ct. 2113. Instead, the issue in Ramdass was whether the defendant was eligible for parole at the time that was relevant for Simmons purposes. See id. at 166-68, 114 S.Ct. 2187.
Third, Rompilla argues that his case is “materially indistinguishable” from Simmons, but we disagree. In Simmons, as noted, the prosecution expressly argued that the defendant posed a future threat, stating that “a verdict for death would be ‘a response of society to someone who is a threat. Your verdict will be an act of self-defense.’ ” Simmons, 512 U.S. at 157, 114 S.Ct. 2187. In this case, by contrast, the Commonwealth made no specific references to any possible future conduct by the defendant. We thus hold that the decision of the Pennsylvania Supreme Court was not “contrary to” Simmons.
2.
Rompilla next contends that the state supreme court’s decision represents an “unreasonable application” of Simmons, but while we agree with the District Court that the application of Simmons to the present case would be “close” if we were exercising plenary review, we are convinced that the state supreme court’s decision was reasonable.
Rompilla maintains that the state supreme court’s decision was unreasonable because its opinion did not discuss all of evidence on which he relies in arguing that his future dangerousness was sufficiently put at issue during the penalty phase of his trial. Rompilla Br. at 45. As we have already explained, however, 28 U.S.C. § 2254(d)(1) calls upon us to decide whether the adjudication of a claim on the merits in state court “resulted in a decision” that “involved an unreasonable application of ... clearly established Federal law.” This standard applies even when a claim is adjudicated on the merits without any discussion at all. See Weeks, 528 U.S. at 237, 120 S.Ct. 727; Chadwick v. Janecka, 312 F.3d at 606. Accordingly, we must look to the reasonableness of what the state supreme court decided, not the detail included in its opinion.
Rompilla argues that the prosecution raised the issue of future dangerousness in its closing by stating that Rompilla had “learned a lesson” from the prior rape, namely, that he should not leave any witnesses and by repeatedly asking the jury whether the similarities between the rape and his murder of Scanlon were not “frightening.” Rompilla contends that these comments painted a picture of him as a “hardened, frightening, violent recidivist who, if ever released, would commit *271additional violent crimes and would not ‘leave any witnesses.’ ” Rompilla Br. at 34-35.
We have given this argument careful consideration, but in the end it does not persuade us that the difficult standard of § 2254(d)(1) is met. Reading the Commonwealth’s remarks in the context of the entire sentencing proceedings, it appears to us that the Commonwealth did not argue future dangerousness. In her emotional closing argument at the penalty phase, defense counsel argued over and over that, although the jury had found the defendant guilty, they must have had some doubts about his guilt in view of the evidence and that they should therefore not impose a sentence of death. She stated:
You, as a Jury, convicted him of First Degree Murder. You convicted him, in your minds, beyond a reasonable doubt, but you must have some doubt. There has got to be some doubt there with no eye witness, with circumstantial evidence....
So I know that you have to have some doubt as to what actually happened that night. We may never know what actually happened that night....
Don’t you want to be sure before you condemn that man to die because don’t fool yourselves. A death sentence is death.... No more questions after that....
I saw you all struggling with this. I saw it Monday night at 10:00 o’clock when we let you go for the evening. You looked tired, you looked nervous, and you looked like you’ve been struggling. ... [I]f you’re struggling with it, the fact that you had some doubt should also stay in your mind, now. If there was any doubt, and I submit to you that there has to be some doubt. There has to be. You don’t know what happened. You’ll never know exactly what happened. There’s got to be some doubt here....
What if you’re wrong? Can you live with that?....
You’ve rendered what you felt was a just verdict. I have no quarrel with you, that was your job, you came back with a verdict but none of you can tell me that you have no doubts and if you have a doubt, then you better think very, very, carefully about what you’re going to do here....
Don’t take a chance that you may be making a wrong decision that you can’t live with. Please, spare his life, thanks.
App. 767-774.
The prosecutor’s remarks upon which Rompilla now relies came in response to these defense comments suggesting that the jury should still have doubts about the defendant’s guilt. Seeking to dispel any such doubts, the prosecutor’s obvious point in stressing the similarities between the circumstances of the rape for which Rom-pilla had previously been convicted and the Scanlon murder was to convince the jury that the same man had committed both crimes. Although the prosecutor at times termed the similarities between the two crimes “frightening,” it seems clear that he did not use this term to suggest that Rompilla was “frightening” in the sense that he posed a future threat, but simply that the similarities were, as he more aptly put it at another point, “astounding.” That his argument did not go to future dangerousness is illustrated by the fact that many of the features of the two crimes that he highlighted — both occurred at a bar, both took place at around closing time, and in both instances the perpetrator used a taxi — are not features that naturally suggest future dangerousness. The prosecutor’s further comment that Rompil-la had learned a lesson from the rape, i.e., *272that he should not leave any witnesses, came immediately after this litany of similarities, and the comment seems to have had two likely purposes: to explain why there was no eyewitness to the most recent crime and to explain why the two crimes differed in the important respect that one involved a killing and the other did not.
In any event, even if this interpretation of the prosecutor’s comments is incorrect and even if they were meant to imply that Rompilla would present a future danger if he was ever released from prison, the fact remains that the prosecutor never actually argued that Rompilla presented a future threat. Concluding that these facts did not bring the case within the holding of Simmons, as set out in the controlling concurrence, is by no means “unreasonable.” Particularly in view of the fact that the Justices who endorsed the controlling concurrence in Simmons apparently felt that it was important to draw the line where they did, rather than approving the arguably broader reach of the plurality, the state court’s failure to extend Simmons to situations in which the prosecution does not argue future dangerousness was not an “unreasonable application” of Simmons.22
Rompilla also argues that the state supreme court’s decision is an unreasonable application of Supreme Court law because it “flies in the face of’ the state court’s prior decisions regarding future dangerousness and prior criminal history and thus violates the Eighth and Fourteenth Amendment requirements that capital sentencing be applied consistently and with an even hand (citing Eddings v. Oklahoma, 455 U.S. 104, 126, 102 S.Ct. 869, 71 L.Ed.2d 1 (1982), and Gardner v. Florida, 430 U.S. at 349, 361, 97 S.Ct. 1197, 51 L.Ed.2d 393 (1977)). Rompilla Br. at 44. In making this argument, Rompilla points to the passage in the state supreme court opinion addressing his argument that his future dangerousness was put at issue for Simmons purposes by the prosecution’s effort to prove as an aggravating circumstance that he had a significant history of violent felony convictions. Romplla-2, 721 A.2d at 795. Rejecting this contention, the state supreme court stated that “this aggravating circumstance only addresses Appellant’s past conduct, not his future dangerousness.” Id. Rompilla attacks this reasoning on the ground that the underlying rationale for this aggravating circumstance is that a history of violent felony convictions is a “barometer of future danger.” Rompilla Br. at 44. He therefore contends that the state supreme court’s holding in the present case violates the principle that a state must administer its death penalty statute evenhandedly. There is no merit in this argument.
The constitutional principle on which Rompilla relies demands consistency in a state’s treatment of its capital cases, and we have not been presented with any evidence that Pennsylvania does not apply the Simmons standard evenhandedly. On the contrary, it appears to us that Pennsylvania has uniformly required a Simmons *273instruction when the prosecutor specifically raised the issue of future dangerousness, see, e.g., Commonwealth v. Trivigno, 561 Pa. 232, 750 A.2d 243, 252-54 (2000) (prosecutor asked jury to use prior convictions as a “weather vane looking into the future” and a “determinant of where [the defendant] is going, not just where he’s been”); Commonwealth v. Chandler, 554 Pa. 401, 721 A.2d 1040, 1046-47 (1998) (prosecutor asked jury to “stop [the defendant] from ever killing another woman again”), and has not required the instruction when the prosecutor only presented evidence of prior convictions. E.g., Commonwealth v. Robinson, 554 Pa. 293, 721 A.2d 344, 355 (1999) (prosecutor only made references to defendant’s past dangerousness); Commomvealth v. King, 554 Pa. 331, 721 A.2d 763, 779 (1998) (prosecutor only made reference to defendant’s past violent acts); May, 710 A.2d at 47 (prosecutor did not argue future dangerousness). See also Robinson, 721 A.2d at 355 (recognizing that the court requires a Simmons instruction only when future dangerousness is “expressly implicated”).
Rompilla does not dispute the fact that Pennsylvania applies the Simmons rule evenhandedly. Instead, his complaint is that there is, in his view, a logical inconsistency between the rationale for the aggravated in question and the Pennsylvania Supreme Court’s interpretation of Simmons. This argument, however, is invalid for numerous reasons. First, the constitutional principle on which Rompilla relies concerns consistency in the treatment of cases, not logical consistency in all aspects of a state’s death penalty jurisprudence. Second, Rompilla has not identified a logical inconsistency. The Legislature may have adopted the aggravating circumstance in question wholly or partially for the purpose of retribution, not to protect the public from those defendants who are likely to pose a threat. Moreover, even if this aggravating circumstance was intended solely to serve as a “barometer of future danger,” there is nothing illogical about taking the position that, while proof of a defendant’s past history of violence may tend to suggest that the defendant may pose a future danger if released, the jury should be instructed about parole only in those cases in which there is a particularly strong reason to think that concern about future danger will decisively influence the jury’s sentence. Informing a jury about the correctional consequences of a verdict is an exception from usual practice, and it is not illogical to confine this exception to narrow circumstances. Third, if there is a logical inconsistency, it flows from the fine line drawn by the controlling opinion in Simmons, not from the Pennsylvania Supreme Court. For all these reasons, Rompilla’s argument is rejected.
IX.
For the reasons set out above, the decision of the District Court is reversed with respect to the ineffective assistance of counsel claim and affirmed as to the accomplice liability instruction and parole ineligibility claims.
. While the case was pending on direct appeal, Rompilla filed a petition for a writ of habeas corpus in the United States District Court for the Eastern District of Pennsylvania. The District Court dismissed the petition without prejudice for lack of exhaustion. Rompilla v. Love, No. 94-cv-4196 (E.D.Pa.).
. The claims as identified by the District Court were as follows:
(1)Trial counsel were ineffective at the capital sentencing phase for failing to investigate, develop and present significant mitigating evidence related to petitioner's traumatic childhood, alcoholism, mental retardation, cognitive impairment and organic brain damage;
(2) Petitioner is entitled to relief from his conviction and death sentence because of the trial court’s improper instruction on accomplice liability;
(3) The trial court’s failure to instruct the jury that "life imprisonment” means life without possibility of parole, even after the jury repeatedly asked about parole eligibility; and the trial court's provision, instead, of inaccurate and misleading information, violated petitioner’s Sixth, Eighth and Fourteenth Amendment rights;
(4) Petitioner is entitled to relief from his death sentence because the (d)(8) aggravating circumstance was unconstitutionally obtained;
*239(5) Petitioner is entitled to relief from his death sentence because the (d)(9) “significant history” of felony convictions aggravating circumstance is unconstitutionally vague; the jury instructions did not cure this vagueness; and the jury instructions, to the extent they provided guidance at all, directed a finding of this aggravating circumstance;
(6) Petitioner is entitled to relief from his death sentence because of improper prose-cutorial argument at the penalty phase;
(7) Petitioner is entitled to relief from his death sentence because the trial court improperly allowed the prosecutor to read to the jury the inflammatory and prejudicial testimony of the victim of a prior rape and counsel were ineffective for failing to cite controlling authority that would have prevented the introduction of the inflammatory and prejudicial evidence;
(8) The seating of the juror who visited the scene of the crime ten times, including, during the trial proceedings, who knew the victim of the offense and the victim's son, who knew an employee of the prosecutor's office and who expressed substantial doubts regarding the presumption of innocence; and trial counsel's failure to challenge this juror for cause, violated petitioner’s sixth, eighth and fourteenth amendment rights;
(9) Petitioner's death sentence should be vacated because the arbitrary "proportionality review” performed by the Pennsylvania Supreme Court violated his Eighth Amendment and Fourteenth Amendment rights;
(10) Petitioner is entitled to an evidentiary hearing on his claim that the prosecution violated his due process by introducing false and misleading evidence; and
(11) Petitioner is entitled to relief because of cumulative prejudicial effects of errors in this case.
Rompilla, 2000 WL 964750.
. A certificate of appealability was not required for the Commonwealth's appeal of the ineffective assistance of counsel claim. Fed. R.App. P. 22(b)(3). The District Court granted a certificate of appealability as to the parole ineligibility claim, Rompilla, 2000 WL 964750, at *21, and we granted a certificate of appealability as to the accomplice liability instruction claim. 28 U.S.C. § 2253(c).
. “The Reitan Battery measures organic impairment by means of a variety of exercises testing concentration, coordination, memory, motor control, abstract abilities and other cognitive and physical functions.” Barker v. Secy. of Health and Human Services, 882 F.2d 1474, 1476 (9th Cir.1989).
. The Minnesota Multiphasic Personality Inventory or "MMPI” is "one of the best known and widely used personality assessment tests.” Richard Sloane, The Sloane-Dorland Annotated Medical-Legal Dictionary — 1992 Supplement 522 (1992).
.The Rorschach test is "a projective psychological [test] in which the subject reveals his or her attitudes, emotions, and personality by reporting what is seen in each of 10 inkblot pictures.” Stedman's Medical Dictionary 1808 (27th ed.2000).
. The Rotter Incomplete Sentences Blank Test tests maladjustment by providing the beginning of sentences (e.g., 'T feel “My nerves ...") that are completed by the subject. See www.cps.nova.edu/cpphelp/ROT-TER.hrml.
. The Wechsler Adult Intelligence WAIS Revised is a test that measures general intelligence in adults. Stedman's Medical Dictionary, supra, 1596.
. Rompilla takes exception with the first prong of the Pennsylvania formulations— whether the underlying claim has arguable merit. Although the question of the merit of an underlying claim is not an explicit step under Strickland, we have held that it is a *249determinative factor in the "deficient performance” prong of the Strickland analysis in at least some contexts. See Parrish v. Ful-comer, 150 F.3d 326, 328 (3d Cir.1998) (counsel not ineffective for failing to raise meritless claims).
. Rompilla notes that the third Pennsylvania prong, as stated by the Pennsylvania Supreme Court’s opinion, asks whether counsel's act or omission "would have” produced a different outcome, not whether, as stated in Strickland, there is a reasonable probability of a different outcome. Strickland, 466 U.S. at 694, 104 S.Ct. 2052. Since neither the decision of the state supreme court nor our decision in this appeal turns on the issue of prejudice, we have no occasion to explore the question whether in practice prejudice is analyzed differently under these two standards.
. For this reason, the authority cited by Rompilla is inapposite. See Jermyn, 266 F.3d at 275 (counsel knew that expert was willing to testify regarding defendant's abusive childhood and its mitigating effects on the defendant's adult life); Profitt v. Waldron, 831 F.2d 1245, 1246-49 (5th Cir.1987) (counsel knew defendant escaped from mental hospital shortly before the crime); Beavers v. Balkcom, 636 F.2d 114, 115-16 (5th Cir.1981) (counsel knew of defendant's prior hospitalization in mental institution); Glenn v. Tate, 71 F.3d 1204, 1208 (6th Cir.1995) (counsel knew defendant had received mental health counseling) cert. denied, 519 U.S. 910, 117 S.Ct. 273, 136 L.Ed.2d 196 (1996); Antwine v. Delo, 54 F.3d 1357, 1365-66 (8th Cir.1995) (counsel knew that defendant was acting "odd” prior to the offense) cert, denied sub nom, Bowersox v. Antwine, 516 U.S. 1067, 116 S.Ct. 753, 133 L.Ed.2d 700 (1996); Hill v. Lockhart, 28 F.3d 832, 838-40, 845 (8th Cir.1994) (counsel knew of defendant's prior hospitalization); Kenley, 937 F.2d at 1300, 1304-06 (counsel knew of but failed to contact a doctor who had previously treated the defendant); Clab-ourne v. Lewis, 64 F.3d 1373, 1377, 1388 (9th Cir.1995) (counsel knew defendant was mentally impaired at the time of the offense, and had " displayed] a broad spectrum of psychiatric and emotional disorders”); Wallace v. Stewart, 184 F.3d 1112, 1114, 1116 (9th Cir. 1999) (counsel knew from first sentencing hearing of defendant’s "chaotic upbringing,” substance abuse, and mother's mental illness) cert. denied, 528 U.S. 1105, 120 S.Ct. 844, 145 L.Ed.2d 713 (2000).
. Both Drs. Sadoff and Cooke had previously testified in criminal proceedings. See, e.g., United States v. Green, 544 F.2d 138, 144 (3d Cir. 1976) (Sadoff and Cooke); New Jersey v. Zola, 112 N.J. 384, 548 A.2d 1022, 1030 (1988) (Sadoff and Cooke); Commonwealth v. Comitz, 365 Pa.Super. 599, 530 A.2d 473, 474 — 75 (1987) (Sadoff); Commonwealth v. Stark, 363 Pa.Super. 356, 526 A.2d 383 (1987) (Sadoff). They had also previously testified in capital cases. See, e.g., New Jersey v. Pitts, 116 N.J. 580, 562 A.2d 1320, 1325-27 (N.J. 1989) (Sadoff and Cooke); Commonwealth v. Aulisio, 514 Pa. 84, 522 A.2d 1075, 1087 (1987) (Cooke); Commonwealth v. Terry, 513 Pa. 381, 521 A.2d 398, 405, 409 (1987) (Cooke); Commonwealth v. Whitney, 511 Pa. 232, 512 A.2d 1152, 1157 (1986) (Cooke); Commonwealth v. Terry, 501 Pa. 626, 462 A.2d 676 (1983) (Sadoff and Cooke).
. As Rompilla points out, police reports on the Scanlon case indicated that "Rompilla was drinking heavily and was intoxicated and incoherent around the time of the offense.” Rompilla Br. at 92.
. In finding the state courts’ analysis unreasonable, the District Court relied in part on the absence of any "in depth analysis” of the duty to investigate, including the lack of any reference to the ABA Standards for Criminal Justice. Rompilla, 2000 WL 964750, at *9. Three important observations must be made about the District Court’s treatment of this point. First, the state court's failure to discuss these standards does not mean that the standards themselves or the principles they embody were not considered. Second, we see nothing in the quoted portions of the ABA standards that dictates that records of the sort at issue here must always be sought. Third, although the ABA standards are important guides, they cannot be viewed as a codification of the requirements of the Sixth Amendment. In Strickland, the Supreme Court recognized that "[prevailing norms of practice as reflected in American Bar Association standards and the like ... are guides to determining what is reasonable.” Strickland, 466 U.S. at 688, 104 S.Ct. 2052 (emphasis added). See also Williams, 529 U.S. at 396, 120 S.Ct. 1495. However, the Supreme Court has made it clear that the ABA standards are only guides. No particular set of detailed rules for counsel’s conduct can satisfactorily take account of the variety of circumstances faced by defense counsel or the range of legitimate decisions regarding how best to represent a criminal defendant. Any such set of rules would interfere with the constitutionally protected independence of counsel and restrict the wide latitude counsel must have in making tactical decisions .... [T]he purpose of the effective assistance guarantee of the Sixth Amendment is not to improve the quality of legal representation, although that is a goal of considerable importance to the legal system. The purpose is simply to ensure that criminal defendants receive a fair trial.
Strickland, 466 U.S. at 688-89, 104 S.Ct. 2052 (citation omitted). See also Roe v. Flores-Ortega, 528 U.S. 470, 481, 120 S.Ct. 1029, 145 L.Ed.2d 985 (2000) (the Court has "consistently declined to impose mechanical rules on counsel' — even when those rules might lead to better representation”).
. See Commonwealth v. Bonomo, 396 Pa. 222, 151 A.2d 441, 446 (1959).
.' On direct appeal, the state supreme court described Rompilla’s argument as follows:
by being instructed on an accomplice theory and then being told to disregard it, the jury might have been confused and convicted [Rompilla] as an accomplice.
Rompilla-1, 653 A.2d at 631.
. In the PCRA appeal, Rompilla again attempted to challenge the trial judge’s instruction on accomplice liability, but the state supreme court held that relief was unavailable because the claim had already been litigated on direct appeal. Commonwealth v. Rompilla, 554 Pa. 378, 721 A.2d 786, 793 (1999).
In the federal habeas proceeding, the District Court also found that the instruction did not prevent consideration of exculpatory and mitigating evidence and that Rompilla’s claim that there was evidence of an accomplice was not supported by the record. Id.
. Simmons applies here because it was decided before Rompilla's conviction became final upon conclusion of his direct appeal in 1995. Cf. O’Dell v. Netherland, 521 U.S. 151, 156-57, 117 S.Ct. 1969, 138 L.Ed.2d 351 (1997).
. Justice Souter's concurring opinion, in which Justice Stevens joined, was phrased in seemingly broader terms. See 512 U.S. at 172, 114 S.Ct. 2187 (Souter, J., concurring)(''at least when future dangerousness is an issue....”). The Simmons dissenters interpreted the plurality opinion as apparently requiring admission of parole ineligibility even when the prosecution does not argue future dangerousness. Id. at 183, 114 S.Ct. 2187 (Scalia, J., joined by Thomas, J., dissenting).
. Kelly was decided after briefing was completed and before oral argument in this case. Rompilla submitted a tJotice of Supplemental Authority, pursuant to Fed. R.App. P. 28(j). After oral argument both parties submitted supplemental memoranda addressing the issue of whether Kelly was applicable to the instant matter.
. Rompilla refers to the Skipper Court’s statement that "[cjonsideration of a defendant's past conduct as indicative of his probable future behavior is an inevitable and not undesirable element of criminal sentencing.” 476 U.S. at 5, 106 S.Ct. 1669. If this dictum is true — that people will inevitably draw inferences of probable future behavior from evidence of past conduct — it may argue against drawing the line suggested in Justice O'Con-nor’s Simmons concurrence between cases in which the prosecution argues that a defendant presents a future danger and cases in which the facts give rise to an inference of future dangerousness. But that plainly does not make the decision of the Pennsylvania Supreme Court in this case "contrary to” Skipper, which was not even a Simmons case.
. Rompilla points to the testimony regarding his parole status and the lack of rehabilitative services as indicating that his future dangerousness was an issue for the jury. This evidence was brought out by defense counsel on direct examination of Rompilla's witnesses and was not argued by the Commonwealth. Rompilla also points to the jury's questions regarding parole and future dangerousness. Although the questions may demonstrate that the juiy did not know the meaning of ''life'' imprisonment, see Simmons, 512 U.S. at 170 n. 10, 114 S.Ct. 2187; id. at 178, 114 S.Ct. 2187 (O'Connor, J., concurring); Rompilla-2, 721 A.2d at 795 (Flaherty, C.J., dissenting), a jury's uncertainty as to parole ineligibility is insufficient to require an instruction under Simmons.