dissenting:
[Fernando Belmontes] was convicted on extremely strong evidence that he committed an intentional murder of extraordinary brutality. He bludgeoned McConnell to death with an iron dumbbell bar; the force of the 15 to 20 some-odd blows leaving her with gaping wounds and a cracked skull. Her defensive wounds plainly evidenced a desperate struggle for life at defendant’s hands. The murder occurred in the course of a calculated plan to burglarize the victim’s home; to which defendant had gained entry on false pretenses. After the murder, defendant and his accomplices callously fenced the victim’s stereo components for $100 — purchasing beer with a portion of the proceeds.
People v. Belmontes, 45 Cal.3d 744, 248 Cal.Rptr. 126, 755 P.2d 310, 354 (1988).
In the penalty phase of his trial in state court, the jury considered the circumstances of Belmontes’s crime and the other aggravating evidence, balanced the evidence against the mitigating factors, and sentenced Belmontes to death.1 Unanimously affirming Belmontes’s conviction and sentence, the California Supreme Court stated: “The properly admitted aggravating evidence in this case — in particular, the circumstances of the crime — was simply overwhelming.”2 Id. at 809, 248 Cal.Rptr. 126, 755 P.2d 310 (citation omitted and emphasis added).
Now our court orders grant of habeas, faulting the state jury’s verdict on grounds of ineffective assistance of counsel. Re-characterizing the aggravating evidence as “minimal,” the majority claims that Bel-montes was prejudiced by his counsel’s failure to present certain available mitigating evidence to counterbalance the aggravating evidence presented by the state. Maj. Op. at 840. The majority also concludes that Belmontes’s counsel failed to prepare adequately the penalty phase witnesses. In order to discern prejudice, the majority overstates the mitigating evidence, understates the properly admitted aggravating evidence, and ignores the further aggravating evidence that would have *880come in on rebuttal. With all due respect, I must dissent.
I
A
To prevail on an ineffective assistance of counsel claim, a petitioner must demonstrate that his counsel’s performance was both deficient and prejudicial. Strickland v. Washington, 466 U.S. 668, 693, 104 S.Ct. 2052, 80 L.Ed.2d 674 (1984). “[A] court need not determine whether counsel’s performance was deficient before examining the prejudice suffered by the defendant as a result of the alleged deficiencies.... If it is easier to dispose of an ineffectiveness claim on the ground of lack of sufficient prejudice, which we expect will often be so, that course should be followed.” Id. at 697, 104 S.Ct. 2052. Prejudice exists only if “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.
The majority concludes that Belmontes has shown both deficiency and prejudice, but its analysis deprives the prejudice requirement of meaning. After holding the penalty-phase performance of John Schick, Belmontes’s trial counsel, to be deficient, the majority concludes that the missing mitigating evidence would have had a reasonable probability of changing the jury’s verdict. In recounting the aggravating evidence, Maj. Op. at 840, the majority fails to mention the circumstances of the crime — although the first factor California law requires the jury to consider when setting the penalty, see CaLPenal Code § 190.3, supra note 1. Even worse, the majority ignores the devastating aggravating evidence that would have been admitted on rebuttal.
In particular, the prosecution would have shown that Belmontes had murdered Jerry Howard in 1979. Howard’s body was found in a secluded, semi-rural area. He had been executed with a bullet to the back of the head. A parole report prepared for Belmontes on May 11, 1979, remarked that “the method in which the murder was carried out indicate[d] planning, sophistication, and premeditation.” Witness testimony offered strong evidence against Belmontes. However, “because of lack of cooperation on the part of the witnesses, [Belmontes] could not be tried for murder.”3 Still, the police could prove that Belmontes possessed the gun used to kill Howard, so Belmontes agreed to plead to a charge of accessory after the fact to voluntary manslaughter. The police remained convinced of his principal role.
Once shielded from prosecution by double jeopardy, Belmontes confessed to several persons that he had shot Howard. While investigating Belmontes’s criminal history in preparation for the McConnell murder trial, both Schick and the district attorney discovered that these persons, unlike the witnesses in 1979, were willing to testify. They included Belmontes’s case worker at the California Youth Authority (“CYA”), Charles Sapien, who told the district attorney in 1982 that Belmontes had confessed to shooting Howard. Sapien recounted that Belmontes had denied the crime during his incarceration at CYA, but had confided to Sapien upon his release that he had “wasted that guy.” 4 Another *881witness was Steven Cartwright, who informed the district attorney that Bel-montes had confessed to him that he had killed Howard, but that in 1979, Bel-montes’s mother had begged him not to testify. Another witness was Detective Jake Donaldson, a longtime Mend of the Belmontes family, who told Schick’s investigator that the Howard killing “was definitely an execution type murder with [Bel-montes] being the principal involved.” Belmontes does not deny the truth of this evidence.
The prosecutor at Belmontes’s 1982 trial was ready to present these witnesses and other evidence of Belmontes’s criminal history. However, the court granted Schick’s motion to limit the extent of testimony to the crime of conviction: accessory after the fact to voluntary manslaughter.
Both parties were aware, however, that the trial court might admit the Howard evidence for other purposes, such as to rebut or to impeach testimony of character witnesses for the defense. See Cal. Evid. Code § 1102(b) (permitting the prosecution to use character evidence, including prior bad acts, “to rebut evidence adduced by the defendant”). The trial transcript substantiates the risk cross-examination posed to the defense. At one point, the defense attorney inadvertently elicited testimony from Belmontes’s friend Robert Martinez that Belmontes was not a violent person. Outside the hearing of the jury, the prosecutor informed defense counsel and the court that he intended “to cross-examine [Martinez] fully about his knowledge of other violent actions done by Mr. Belmontes” unless the court struck the evidence from the record. He noted that “counsel was well aware of all the witnesses I have lined up to testify to [Bel-montes’s violent past].”5 The court agreed: “I’m going to have to allow him to go into the whole background if we don’t do that.” (emphasis added). Schick immediately acquiesced; the judge ordered Martinez’s character testimony stricken from the record and admonished the jury to disregard it. This incident leaves little doubt that the court was ready to admit the Howard evidence for rebuttal or impeachment.
When later deposed, Schick confirmed that the Howard evidence had given him “grave concerns” and that he had structured his arguments and witnesses to avoid its admission.6 He told habeas counsel that the prosecution had intended to call Detective Donaldson, who would have testified to the “cold-blooded fashion” in which Howard had been killed. When asked whether he believed such evidence would be “devastating,” Schick said: “Certainly.”
But, Belmontes now argues that the trial court would not have allowed the evidence because it was not relevant to impeach expert testimony regarding Bel-montes’s prospects for nonviolence in an institution. Yet for a mental state expert to determine whether Belmontes had a lesser proclivity toward violence when supervised, she would have needed to *882compare his behavior in both institutional and noninstitutional settings.
Moreover, the manner in which Bel-montes killed Howard would have been relevant to his institutional prospects directly, insofar as it manifested aspects of his personality. The defense supported its claim that Belmontes would be nonviolent in prison with evidence that a well-respected psychological test7 suggested that he had the personality of a “conformer.” To rebut an expert’s interpretation of that test, the prosecutor could have asked whether the expert was aware that Bel-montes had taken a leadership role in the murder of Jerry Howard or had helped establish a Chicano gang while incarcerated — acts that suggested an aggressive personality and undermined the claim that he would be a conforming and rule-abiding inmate.8
B
The majority bifurcates its analysis in an attempt to avoid the minefield of Bel-montes’s criminal history. While it concedes that Belmontes’s violent acts, might be admissible if Belmontes asserted a likelihood of nonviolent prison adjustment, it declines to consider that issue on the ground that the other mitigating evidence suffices to establish prejudice. This approach simply leads the majority into a neighboring minefield: the circumstances of the Howard murder would have been admissible to rebut the other mitigating evidence as well.9
The majority states that “Schick should have offered the testimony of a psychologist or psychiatrist in order effectively to explain to the jury in day-to-day terms the practical impact on an individual of the kind of traumas that Belmontes experienced as a child and adolescent.” Maj. Op. at 868. Had Schick done so, the prosecution could have cross-examined such expert as to the basis for her opinion. California law provides that “a witness testifying as an expert may be crossexamined to the same extent as any other witness and, in addition, may be fully cross-examined as to (1) his or her qualifications, (2) the subject to which his or her expert testimony relates, and (3) the matter upon which his or her opinion is based and the reasons for his or her opinion.” Cal. Evid.Code § 721(a) (emphasis added). If Schick had placed on the stand an expert to “explain[] the extent to which [Bel-montes’s childhood] problems can cause or contribute to a change in individuals that can lead to subsequent criminal conduct,” Maj. Op. at 868, the expert would have needed to know the criminal conduct in which Belmontes had engaged. The Howard murder evidence would have been admissible to show the basis for the expert’s opinion or to reveal the expert’s failure to consider relevant acts in Belmontes’s history.
The Howard evidence would also have been relevant to question expert testimony *883as to Belmontes’s mental state at the time of McConnell’s murder. The majority asserts that “[b]y the time of McConnell’s murder-indeed earlier than then-[Bel-montes] was regularly using marijuana, heroin, LSD, PCP and other drugs.” The Howard evidence would have been relevant to rebut any insinuation that the McConnell murder was in any way affected by Belmontes’s drug use.10 Dr. Yates explained that an expert could have opined whether Belmontes had “an antisocial personality disorder or simply [was] a conformist individual who was under special stress at the time.” If the expert had suggested that Belmontes lost control and awareness of his impulses due to drugs or alcohol, the Howard evidence could have shown that Belmontes committed a similarly “cold-blooded” murder without such influences.
Therefore, far from leading to prejudice, the omission of expert mental-state evidence saved Belmontes from devastating cross-examination evidence. As Schick explained:
[I]t bec[ame] apparent that the amount of evidence the prosecution was trying to introduce in this penalty trial, should we get there, was growing in leaps of bounds [sic ].... [Belmontes’s prior convictions] were somewhat small in my mind next to the other factors, all of which related to this 1979 homicide of Jerry Howard. Because, as I said, it was very clear to me that what [the prosecutor] wanted to do was retry that case, put all the evidence before the jury.
Schick noted that the prosecutor’s damaging evidence was compounded
[by] the statement [Detective Donaldson] made to [the defense investigator] that it was his ... view that Mr. Bel-montes had done that killing in 1979 in a cold-blooded fashion. And what [the prosecution] wanted to do was explain that point of view ... and at the conclusion of it get up to the jury and say, “Here is a man who has been convicted not once but twice of murder.” That’s a whole different kettle of fish .... getting back to your question, yes, I was concerned. That was my concern.
C
Our precedent recognizes that counsel’s concern for opening the door to rebuttal can defeat a claim of ineffective assistance of counsel. In R. Campbell v. Kincheloe, 829 F.2d 1453 (9th Cir.1987), counsel had presented no mitigating evidence, yet we defended that omission:
*884The record shows that the state was prepared to present a vast array of aggravating evidence in rebuttal, including the forcible rape of Campbell’s ex-wife. ... Faced with the choice of limiting the state to a relatively tame presentation of Campbell’s prior convictions, or potentially opening the door to devastating rebuttal evidence, Campbell’s counsel chose the former route by electing not to present mitigating evidence. In one of the attorney’s words, “[presentation of those [mitigating] items in my mind would bring forth a parade of horribles that in my opinion would so far bury those factors in mitigation that any chance we had of saving his life would have been lost.”
Id. at 1462 (emphasis added). We noted that the defendant, like Belmontes,
concede[d] that some of his potential mitigating evidence would have been met with strong rebuttal evidence from the state, but he speculated] that evidence of his “background, childhood and family relationships,” and possibly evidence of his “child abuse, upbringing and drug abuse,” could have been presented without opening the door to rebuttal evidence.
Id. Still, we found no prejudice: “Even if this is the ease, we agree with the district court that ‘given the overwhelming aggravating] factors,’ and ‘the heinous nature of the crime,’ there is no reasonable likelihood that the jury’s verdict would have been different had the mitigating evidence been introduced.” Id.
Here, as in Kincheloe, the state was prepared to present a vast array of aggravating evidence in rebuttal, including Belmontes’s execution-style murder of Howard, his history of drug dealing, his conflicts with police, and his participation in gang activities. Even without that further aggravating evidence, the circumstances of the crime already were “simply overwhelming.”
Furthermore, the majority’s attempt to avoid the issue of rebuttal evidence requires it to also ignore mitigating evidence that Belmontes himself deemed crucial: evidence that Belmontes would be nonviolent in prison. As Belmontes stated in his amended habeas petition in the district court:
Common sense tells us that a rational jury will be extremely reluctant to award a life sentence if it would be exploited as a license to assault or kill again. In contrast, a life sentence becomes far more palatable to a jury which can satisfy their primary interest in removing the defendant from open society with some certainty that he will not replicate violent offenses in prison society.
In the face of the gruesome circumstances of the crime and the already-admitted evidence of Belmontes’s prior violent acts, the jury would not have had such certainty unless Schick introduced evidence of his non-violent potential. Because he was unable to do so without opening the door to devastating rebuttal evidence, the omission of such evidence was not prejudicial.
II
A
The mitigating effect of the omitted evidence would not have created a reasonable probability of altering the sentence. First, one must distinguish between evidence that was already presented, and evidence that was never admitted. The majority intermingles the two, leaving the impression that Schick omitted mitigating evidence that he in fact presented to the jury. For example, Schick presented numerous penalty phase witnesses to “humanize” Belmontes and to show that, despite a *885difficult background, Belmontes could relate to others.11 He called to the stand Belmontes’s mother, grandfather, his friends Darlene and Robert Martinez, Rev. Dale Barrett (chaplain at CYA Pine Grove Facility), the Haros (members of Rev. Barrett’s church), and Don Miller (assistant chaplain at the CYA Preston Facility).
The majority considers the testimony of these witnesses to be of little value compared to the testimony that Schick could have presented. In particular, the majority objects that “[a]t no point did Schick mention any of the traumatic experiences that Belmontes underwent during his childhood or his youth,” thereby “failfing] to explain to the jury how those experiences affected Belmontes; what the relationship was between the tragic events and Belmontes’s subsequent criminal conduct; and why the jury should consider those circumstances in determining whether Bel-montes was an individual who should be put to death or whose life should be spared.” Maj. Op. at 846-47. But the majority fails to give proper emphasis to the fact that several witnesses testified on those issues: Belmontes’s mother spoke of how Belmontes’s father used to beat her, once breaking her arm, and another time stabbing her and of how Belmontes suffered from the departure of her second husband and became “difficult to control.” Belmontes’s grandfather described how his grandson cared for his grandmother, visiting her every day in the hospital and attending her funeral. The jury did not need an expert to understand that these experiences had a negative impact on Bel-montes.
B
Nor was Belmontes prejudiced by the lack of expert testimony about his rheumatic fever. Dr. Yates characterized that illness as “pretty mild,” rather than “significantly debilitating,” as the majority asserts. She clarified that “[ajctually, it was the mother that expected him to die early, but[Belmontes himself] didn’t.” 12 According to Dr. Yates, the illness “wasn’t very severe, it was associated with [ ] arthritis, but not with anything more ominous and he probably shouldn’t have had a home teacher.”13 Dr. Missett similarly stated that Belmontes “did not face an illness that was going to result in imminent death.”
Belmontes never was diagnosed with a depressional disorder. In fact, Dr. Yates stated that it would have been inappropriate to diagnose Belmontes with a de-pressional disorder, attributing his unhappiness during home-schooling to “a situational depression, which ... just means that it’s not a good situation and he doesn’t like it and doesn’t feel good about it.” Dr. Missett opined that certain events in Belmontes’s childhood corresponded with a form of “symptomatic” depression. For example, he remarked that “[i]f [Belmontes was] to be believed about his visits to [his infant sister’s] *886grave, this would have been an indication of an early essentially childhood depression.” And he stated that the “description of [Belmontes] not liking school and the feeling of not getting much out of it [to be] consistent with his having a symptomatic childhood depression.” Those triggering causes for depression offered little reason to believe the depression was serious or debilitating.
On the other hand, Dr. Missett did suggest that Belmontes’s sickness as a child might have led to his later use of drugs: “Belmontes’s drug abuse appears to have had its onset during and immediately after the period of time that he was so repeatedly physically ill.” He opined that Bel-montes might have used drugs as a form of “self-medication.”. Although this evidence might have led the jury to pity Belmontes, the prosecutor could have brought in damaging evidence on crossex-amination. For example, the prosecutor could have queried of such expert whether depression also induced Belmontes to deal and to distribute drugs. That rebuttal evidence would have undercut Schick’s efforts to transform Belmontes’s drug-related conduct into a cause for sympathy.14
C
Belmontes’s drug use would not have carried much weight to humanize him as the majority would suggest. When deposed for habeas purposes, Schick’s trial mental-state expert, Dr. Cavanaugh, opined that Belmontes had a “clear mental status at the time of the incident [murder of McConnell].” He stated that Belmontes claimed to have been high on drugs shortly before the crime, and yet his “recounting of the events leading up to this murder was very, very detailed” — a detailed description inconsistent with a person whose actions were influenced by drugs.15 Moreover, the way in which the crime was planned and committed indicates forethought and control: Belmontes armed himself with a metal bar and put on gloves16; after the crime, Belmontes had the lucidity to discard the bloody weapon in a river.
Dr. Yates thought that the evidence of Belmontes’s mental state at the time of the crime could cut either way. On the one hand, his careful preparation and execution of the crime suggested that he retained self control and that his brutal act was representative of his general personality. On the other hand, Belmontes “could have been very impulsive at times.” If he were “under the influence of substances,” Dr. Yates remarked, “[h]is anger could have broken through, even though it wasn’t his ordinary way of acting and feeling and thinking, he could have done something that was horrible.” (emphasis added). The prosecution could have impeached such testimony regarding Belmontes’s “ordinary way of acting and feeling and thinking,” and asked whether that opinion took into account the fact that Belmontes had killed Howard without any evidence of drug or alcohol intoxication. Again, any effort to lessen Belmontes’s culpability for *887the crime would have either been weak or counterproductive.
D
If Schick had offered expert testimony to show that Belmontes’s childhood experiences harmed his ability to interact with others, such testimony would have led to similar rebuttal evidence. For example, Dr. Missett stated Belmontes’s grandfather expressed anti-Latino sentiments toward Belmontes’s father, causing Bel-montes a sense of “inferiority and lower self-esteem.” He opined that it became “difficult [for Belmontes] to mainstréam himself socially or racially into a mixed situation or a largely Anglo situation at school.” Such testimony might have explained why Belmontes decided to join gangs. But Belmontes was not prejudiced by the lack of such explanation, since Schick succeeded in keeping out evidence of gang relations altogether.
The majority also contends that Schick should have introduced mitigating evidence to show Belmontes’s difficult childhood and to emphasize the abuse in the family. However, Belmontes’s mother had already testified to being beaten by Belmontes’s father. And as a psychological expert, Dr. Missett found it significant that Belmontes never asserted that he had witnessed his father hit his mother. Even now, Bel-montes offers no evidence as to how the abuse impacted him and never states that he was abused himself.
Furthermore, several witnesses noted positive aspects of Belmontes’s family relationships. Belmontes’s sister recounted how she and Belmontes went to their father’s on Sundays and “spent the whole day together.” She remembered the days positively, but noted that they “never did much because he never had any money.” When asked whether the financial problems of the family caused Belmontes psychological harm, Dr. Missett opined that the “father’s inability to hold a job even in the face of [ ] poverty,” caused Belmontes a “level of shame.” It is not clear, however, how much that “shame” affected Bel-montes or his relationships, for his sister noted that he “had lots of friends.”
Having painted Belmontes’s childhood in the darkest possible light, the majority attempts to cite sickness and poverty and family troubles as the reason why he became a violent murderer. The majority notes that witnesses who knew Belmontes as a child described him as a “sweet” boy who was polite and pleasing. And as a psychological expert, Dr. Missett noted that Belmontes was “extremely well socialized” and had “a very well-developed capacity to function in a socially attractive way by the time the he [wa]s entering adolescence.” The majority cites these positive features of Belmontes as a child to support its assumption that external factors, and not volition, can be blamed for Belmontes’s criminal transformation.
The majority’s suggestion that Bel-montes’s rheumatic fever caused so dramatic a change in his personality is undermined by the “pretty mild” characterization of that illness by Dr. Yates. And Belmontes’s own sister stated that she “did not notice or understand emotional changes in him” due to his illness — “He was the same easygoing person in the way he related to [her].” And while the majority contends that Belmontes suffered from having to move into a single motel room, his sister recounted that Bel-montes “did not stay at the [] motel very much.” The majority’s suggestion that the jury would have considered Belmontes less culpable for McConnell’s murder, had they known further details about his childhood, is simply implausible.
*888E
The cumulative effect of Belmontes’s childhood experiences would have offered little antidote to the “overwhelming” evidence of Belmontes’s later drug trafficking, involvement in gangs, assault on his girlfriend while she was pregnant, and multiple murders. Schick’s failure to offer further testimony about Belmontes’s childhood experiences was not prejudicial. Even if the jury remained ignorant of the chilling Howard murder, the aggravating evidence presented overwhelmed any benefit of the omitted mitigating evidence. The jury would not have forgotten Bel-montes’s brutality, evidenced by the autopsy photos of McConnell’s mangled head. The jury would have recalled Belmontes’s testimony that he and his friends left McConnell’s bloody body and drove to a place where they could sell her belongings and buy beer. The jury still would have had no explanation for why, even in his closing address, Belmontes expressed no remorse.
Ill
A
Contrary to the majority’s claim, neither Mayfield v. Woodford, 270 F.3d 915 (9th Cir.2001) (en banc), nor Douglas v. Woodford, 316 F.3d 1079 (9th Cir.2003), supports its conclusion.
Mayfield involved a claim of ineffective assistance in a capital sentencing. The majority deems the facts in Mayfield nearly identical to those at bar, with only two significant differences: In Mayfield, the aggravating evidence was “strong” and the mitigating evidence introduced was “substantial”; here the state conceded that the aggravating evidence was “scant” and the mitigating evidence introduced was “insubstantial.” Maj. Op. at 872. The majority’s statement with respect to the strength of the aggravating evidence distorts the state’s reference, which characterized the aggravating evidence other than the circumstances of the crime.17 When the circumstances of the crime were considered in context, the prosecutor made clear that the death penalty was appropriate.
Moreover, the deficiency of Mayfield’s counsel was marked and clearly consequential. Mayfield’s counsel spent only 40 hours on the entire trial and waived opening argument in the penalty phase. May-field alleged that he had been influenced by drugs at the time of the offense, but his counsel “mistakenly stipulated that [his] urine tested negative for PCP the day after the crime, indicating to the jury both that Mayfield did not have a substance abuse problem and that Mayfield had lied about it.” Id. The lawyer called only one witness at the penalty phase. Mayfield, 270 F.3d at 928. Although important,18 this witness’s testimony revealed only a fraction of the mitigating evidence available to Mayfield. At a later state eviden-tiary hearing on habeas, Mayfield’s family *889members, none of whom testified at trial, described how Mayfield was born to a 15-year-old mother and grew up in the projects. They recounted his growing emotional disturbance as he “began drinking and smoking marijuana to fit in with the tough kids of the San Bernardino projects” and started using PCP. Id. at 931. Friends and siblings explained that his “personality changed as a result of his drug and alcohol abuse and his poorly controlled diabetes,” id. at 931, and that he became “incorrigible and occasionally had physical altercations with [his mother].”
Experts at the later proceeding verified that Mayfield had been “diagnosed with childhood behavioral disorder and depression” and described how “[a] psychological evaluation indicated that, although he had low-normal IQ, ‘he actually performed as though he were mildly retarded.’ ” Id. (emphasis added). A psychiatrist explained that “ ‘a growing onslaught of catastrophes, losses, and increased emotional turmoil ... ma[de] it more difficult for him to figure out what is the best thing to do and how to control his emotions.’ ” Id. An endocrinologist detailed the impact of Mayfield’s longterm fight with diabetes, including comas and hospitalizations as frequent as five times a month. This evidence might well have engendered the sympathy of Mayfield’s jury, had it been presented.
Mayfield also had significant positive character evidence evident in his case-that would not have opened the door to devastating rebuttal evidence. Witnesses described Mayfield as “helpful and generous” and recounted that he had looked after his younger brother and sister and had routinely assisted his wheel-chair bound uncle. Id. at 932. Other witnesses told how May-field had aided them to overcome personal struggles, how he loved his son, how he interacted well with children, and how he was not a violent person. Id. Finally, they stated that they loved Mayfield and wished that his life would be spared. Id.
Belmontes had nothing close to this mitigating evidence. Unlike Mayfield’s documented brain damage from physical and mental disorders, Belmontes had “pretty mild” rheumatic fever and “situational” or “symptomatic” childhood depression. In contrast with the evidence suggesting that Mayfield devoted enormous amounts of time to actively assist others, Belmontes’s mother stated that he used his illness as an excuse to be lazy.19 Mayfield and Bel-montes both abused drugs, but Belmontes also dealt them.20 And while no family or friends were presented to testify to the positive aspects of Mayfield’s character, Belmontes had several witnesses who testified on his behalf and still the jury found their words insufficient to justify mercy.21
*890The majority complains that the witnesses did not show “Belmontes’s positive attributes”: that “he was a kind, responsible, and likeable child who got along well with his siblings, was respectful towards his grandparents despite their disapproval of his mixed racial background, participated in community activities, kept up in school and got along with his teachers before his illness, and made friends easily.” Maj. Op. at 864. But several aspects of Belmontes’s positive childhood characteristics were presented: Belmontes’s mother told the jury of his “close” relationship with his sister, his grandfather spoke of Belmontes’s devotion to his grandmother, the jury had learned that Belmontes had assumed a leadership position on his CYA fire crew and had joined the “M2” religious program while in CYA custody. The remaining evidence that could have been presented would have added little: Belmontes was involved in Sea Cadets and little league and many adults found him to be a polite child with a pleasant demean- or.22 Third, evidence that Belmontes “kept up in school” could have been impeached by noting that he was a high-school drop-out.23
Even more importantly, we distinguished the facts in Mayfield from the situation where new mitigating evidence would open the door to additional aggravating evidence. Specifically, we cited the Fifth Circuit’s holding in Williams v. Cain, 125 F.3d 269, 278-280 (5th Cir.1997), in which the court rejected an ineffective assistance of counsel claim because “[the omitted] testimony could have opened the door to testimony regarding [the defendant’s] drug use, expulsion from school, and discharge from [a] job [and] such testimony ‘would have had little mitigating effect against the aggravating evidence.’ ” Mayfield, 270 F.3d at 938 (emphasis added). The only such rebuttal evidence in Mayfield related to Mayfield’s mother’s awareness of “an incident in which May-field may have engaged in inappropriate sexual conduct with his infant sister when he was twelve.” Id. at 928. Had her testimony been the only available testimony, we agreed that this risk “argue[d] against a determination of prejudice.” Id. However, counsel had failed to present any testimony by family or friends, although “family members, except for May-field’s mother, did not have damaging testimony.” Id. (emphasis added).
Belmontes’s case differs from Mayfield because the mitigating evidence Schick could have presented would have elicited a plethora of aggravating rebuttal evidence — evidence that leaves little doubt that the net effect of the additional testimony would have been negative.
Belmontes has not made the required showing of prejudice. There was no “reasonable probability that, but for counsel’s unprofessional errors, the result of the proceeding would have been different.” Strickland, 466 U.S. at 694, 104 S.Ct. 2052. The majority’s discordant conclusion conflicts with Strickland and manifests disagreement with governing precedent. “Unless a defendant makes both showings *891[of deficiency and prejudice], it cannot be said that the ... death sentence resulted from a breakdown in the adversary process that renders the result unreliable.” Strickland, 466 U.S. at 687, 104 S.Ct. 2052. The majority’s view appears to adopt a “per se rule that we must reverse a death sentence if we find that counsel’s performance at the penalty phase was deficient”— a rule we have expressly rejected. Mayfield, 270 F.3d at 928 (citations omitted).
B
Nor can I accept the majority’s facile analogy of this case to Douglas, 316 F.3d at 1079. Contrary to its assertion that “[t]he facts of the case at hand and those in Douglas are quite similar,” Maj. Op. at 859, the two cases differed in crucial respects.
The aggravating evidence in Douglas was powerful: Douglas killed two teenage girls after torturing them and forcing them to commit sex acts. Douglas v. Woodford, 316 F.3d at 1079, 1083 (9th Cir.2003). The omitted mitigating evidence, however, was also powerful: Douglas had been orphaned and placed in foster care; his alcoholic foster father locked him in a closet for long periods of time, causing him permanent claustrophobia. After running away at 15 to join the Marines, “Douglas was arrested and put in a Florida jail where he was beaten and gang-raped by other inmates.” Id. at 1088. Later, Douglas got in a car accident that left him with permanent brain damage. Despite these traumatic experiences and their documented harm to his mental capacity, Douglas had acted heroically even in his older years: he had medals and commendations from the Marines, and witnesses testified that he had saved the lives of two drowning sailors. Id. Our conclusion in Douglas was based on a reasonable probability that the jury would have spared Douglas his life, had it known these sympathetic facts.
In Douglas, as in Mayfield, we confronted no risk that devastating aggravating evidence would enter on crossexamination. The available aggravating evidence against Douglas had already been presented. The case does not compare to Belmontes, where the prosecution had found a skeleton in the closet, and was waiting for Bel-montes to open the door.
IV
Equally troubling is the majority’s conclusion that Schick’s preparation of the penalty phase witnesses was inadequate and prejudicial. The majority states that:
In addition to failing to investigate adequately, Schick did little to prepare the lay witnesses he called to testify.... It is evident from the testimony given at the penalty phase that Schick did not ... [prepare the witnesses].... Several of the witnesses who knew Belmontes best ... did not testify to a single positive quality he possessed.
Maj. Op. at 861 (emphasis added). Without any meaningful discussion of Schick’s actual preparation of the witnesses,24 the majority assumes that the limited appeal of the witnesses’s testimony reflects a lack of coaching.
The majority does not explain what positive qualities were not mentioned, but *892could have been illuminated. Belmontes’s mother already had told the jury that Bel-montes had a close relationship with his sister.25 His grandfather had described Belmontes’s faithfulness to his grandmother. His friends Robert and Darlene Martinez had described their close relationship. Rev. Barrett and the Haros had described the sincere religious commitment Belmontes made during his CYA incarceration. Finally, Miller had testified to Belmontes’s ability to make a positive contribution while in prison.26
The majority faults Schick for allowing the witnesses to state that they believed Belmontes was innocent. Although such view contradicted the jury’s guilty verdict, Schick’s failure to stop the witnesses from so testifying was not objectionable. In fact, this testimony may have had a mitigating effect, because it allowed Schick to present positive character evidence indirectly, without opening the door to a damaging rebuttal. It is hard to imagine that the witnesses’s implication that Belmontes was normally not a violent person prejudiced Belmontes’s hope for leniency.
Y
For the third time, the majority has granted Belmontes habeas relief without the requisite legal or factual support. The mere desire for mercy toward a man found guilty of capital murder, however admirable, provides no legal ground to disturb the jury’s sentence of death. Again, I must dissent.
. California law requires the trier of fact to consider eleven factors in the penalty phase, insofar as they are relevant: (a) the circumstances of the crime, (b) the defendant’s use, attempted use, or threat of force, (c) the defendant’s prior felony convictions, (d) the defendant’s extreme mental or emotional disturbance, (e) the victim’s participation or consent, (f) the defendant’s reasonable belief that his actions were morally justified or extenuated, (g) the defendant's extreme duress or substantial domination by another person, (h) the defendant's mental disease or defect, or the effects of intoxication (i) the defendant’s age, (j) the defendant’s minor role, and (k) "[a]ny other circumstance which extenuates the gravity of the crime even though it is not a legal excuse for the crime.” Cal.Penal Code § 190.3.
. Appellate counsel for Belmontes, in contrast, considers the crime "objectively low on the scale of heinousness.”
. Police records revealed that two days after the crime the police had received a call from an anonymous informant that Belmontes had stated: “I shot that guy in the head.” Another anonymous call informed the police that Belmontes had been seen with Howard just before Howard was killed. Other witnesses contributed circumstantial evidence.
. Sapien explained that Belmontes believed Sapien had aided him obtaining parole, because Sapien had written and presented to *881the parole board the final report before it granted Belmontes’s release.
. He stated that he would test the witness’s knowledge of the facts that as a young man, Belmontes attempted to seize a police officer’s gun during an arrest, that he carried a gun to school because he was having trouble with schoolmates, that he was a member of the Black Angels gang in Ontario, California, and that he murdered Jerry Howard. The record shows that the prosecution had extensive files to back up these allegations.
. Schick stated that he “would have expected” the prosecutor to introduce "[s]pecific facts of the case” to rebut expert testimony about Belmontes's propensity for violence.
. Both parties’ experts testified that they considered this test, the "Jesness" test, a valuable one.
. Dr. Yates testified that if she were to diagnose Belmontes based on the evidence gathered for habeas purposes, she would deem him to have a "socialized aggressive disorder,” based on "evidence of [his] social attachments” and "repetitive pattern of physical violence and thefts.”
.As Belmontes argued in his amended habe-as petition before the district court: "Moreover, and of paramount importance, the same mental state evidence which mitigates his role in the offense itself would have provided a compelling presentation regarding future conduct if given a life sentence rather than the death penalty.” (emphasis in original.)
. The majority states that it is not making a factual finding, inappropriate at the appellate level, as to whether Belmontes was influenced by drug use. Maj. Op. at 865-66 n. 18. Additionally, it states that "the district court did not hold that humanizing evidence about Bel-montes's history of substance abuse before the crime would likewise open the door to additional aggravating evidence.” Id. However, I am at a loss as to how Belmontes’s drug use would be humanizing without some reference to its effect on his commission of a cruel and brutal crime or his ability to adjust to prison life without being a danger to others. Although the majority argues that the drug use evidence is humanizing because it shows that he used drugs "to help cope with the unpleasant circumstances of his life,” without some sort of connection to the crime itself or a "major personality change,” compare Smith v. Stewart, 140 F.3d 1263, 1271 (9th Cir.1998), such mitigating evidence is of little relevance, and perhaps not mitigating at all. See Maj. Op. at 852-53 (explaining that lack of expert testimony was significant because there was no "expert who could make connections between various themes in the mitigation case and explain to the jury how they could have contributed to Belmontes's involvement in criminal activity” (emphasis added)).
.Schick explained that his four goals in the penalty phase were (1) to "humanize” Mr. Belmontes for the jury; (2) to show that he would not be a difficult prisoner and that he could form good relationships with people; (3) to show his background to the jury so that it would know what his life had been like; and (4) to raise lingering doubt whether Bel-montes was really the actual killer by offering evidence of Vasquez’s agreement to testify for the prosecution to obtain a lighter sentence.
. Dr. Missett also noted that he was not sure whether Belmontes, or his mother, believed that Belmontes would die before age 21.
. She also noted that she "s[aw] no reason why he was so impaired that he couldn’t go to school” and speculated that "it may have been coming more from the mother than any [medical necessity].”
.A police report dated March 1, 1979, described how surveillance officers witnessed Belmontes give two balloons of heroin to the confidential informant. After Belmontes parted company with the confidential informant, the informant gave the officers the heroin. He told them that he had promised to try to find an "outfit” (heroin injection paraphernalia) for Belmontes and that Belmontes had warned him that he was armed, had committed at least one murder, and had shot people on two different occasions.
. Other witnesses corroborated the accuracy of Belmontes’s detailed description.
. Belmontes himself told Dr. Yates about the gloves, which he stated he always wore to "do a job.”
. The majority argues that I have incorrectly interpreted statements made by the State at oral argument, however, on this point my colleagues and I will simply have to disagree. Maj. Op. at 870 n. 21.
. The witness, a doctor, testified that May-field had been diagnosed with diabetes at age nine, suffered from a childhood behavioral disorder caused by depression, and began using PCP in his late teens and that his "mental state deteriorated because of drug usage.” Id. at 929. The doctor also revealed that Mayfield repeatedly had expressed remorse and he recounted that others described May-field as a gentle person and the crimes to be out of character. Unfortunately, the mitigating effect of the doctor’s testimony was undermined by his erroneous statement that May-field "was not under the influence of drugs or alcohol the night of the crimes.” Id. at 930.
. Belmontes’s parole agent at CYA recorded this statement in a report on June 13, 1979.
. Belmontes’s girlfriend and the mother of his child, Barbara Murillo, stated that Bel-montes did not use drugs, because they were bad for his illness. Police reports included witness statements and documentation that Belmontes engaged in drug dealing.
. As the defense investigator discovered, several persons who knew Belmontes as a youth had only negative things to say. Members of the Detective Staff at the Ontario Police Department (who investigated the Howard murder) “felt that [Belmontes’s] mother was very over-protective of her son and other siblings.” They noted his reputation as a “heavily involved” member of the Black Angels gang, and stated that he had "a long history of antisocial behavior” and was "very fortunate that he ha[d] not been caught” for the crimes he had committed. Belmontes’s probation officers indicated similar sentiments and noted that he was "very manipulative,” a characterization corroborated by several psychiatric experts.
. At the same time, the fact that he brought a gun to school because he was having trouble with classmates suggested that his relationships with his childhood peers were not as favorable as the majority would suggest. There is little doubt the prosecution could have brought that incident in as rebuttal to evidence of Belmontes’s positive character as a child.
. An attempt by the majority to attribute this decision to leave school to Belmontes’s rheumatic fever would be contradicted by Dr. Yates’s statement that she saw no reason why Belmontes had to leave school even in the worst period of his illness.
. This same failing is reflected in Bel-montes's argument. He focuses on the resulting testimony, without describing what Schick did or did not do to prepare the witnesses. He states that Belmontes received “virtually no support from his obviously nervous and tongue-tied mother” and concludes that the "presentation [of the mother] fell in the same range between 'woefully inadequate’ and ‘deleterious.’ ” But we have no reason to believe that the mother’s nervousness on the stand was the result of inadequate preparation.
. Belmontes argues that the mother should have been shown “photographs of [Bel-montes] actually involved in positive activities as a youth, and [been asked] to identify and describe the contents for the jury.” But counsel enjoys "wide latitude ... in making tactical decisions,” such as selecting which evidence to present to make the most compelling argument. Strickland, 466 U.S. at 689-90, 104 S.Ct. 2052. In any case, Dr. Yates aptly noted that the photographs might not have represented such positive moments: "The pictures are a very small slice of what happened and usually it’s a family affair when people are saying, well, smile now and that’s not necessarily characteristic of anything that goes on in the family.”
. The majority’s analysis erroneously assumes that the witnesses' testimony required explanation: "Although Schick stated in his deposition that one of his four themes at the penalty phase was Belmontes’s capacity to adjust well to prison, he failed to argue that such was the import of the testimony of any of the witnesses he had called to testify.” Maj. Op. at 862. But much of what the witnesses said conveyed a clear mitigating message on its own. For example, Miller said that Bel-montes had returned on several occasions to speak to later CYA wards and to offer them motivating advice. Miller explained that he believed Belmontes could offer similar encouragement and inspiration to fellow prison inmates. The jury did not need Schick to explain "the import of th[at] testimony.” Id.