Dyer, a California state prisoner under sentence of death, appeals from the district court’s denial of his petition for writ of habeas corpus relief under 28 U.S.C. § 2254. We have jurisdiction over this timely appeal pursuant to 28 U.S.C. §§ 1291 and 2253. We affirm.
I
On November 8, 1980, Dyer (armed with a .38 caliber handgun), Michael Jackson (Dyer’s stepbrother), and Cleveland Ario (armed with a .45 caliber semiautomatic pistol) drove to the home of their friend, Belinda Murray. She lived in a two-level apartment in Oakland, California, along with her brother Floyd, her friend Nora Fluker, and Fluker’s four children. Dyer, Jackson, and Ario brought cocaine and a bottle of wine, which they drank.
Some time later, Belinda Murray’s friend, Bennie Warren, arrived. Warren had never met Dyer before, but found him to be “stable-minded,” “intelligent,” and entirely in control of himself. Later, Belinda Murray, Dyer, Jackson, and Ario went upstairs to Belinda’s bedroom. Warren was told to stay downstairs. Once upstairs, Ario injected Belinda Murray, Dyer, and himself with a “speedball” — a mixture of heroin and cocaine. Jackson and Fluker also used the drugs. Dyer appeared to have received a small dose, which had no apparent effect on him.
Dyer, Jackson, and Ario then left Belinda Murray’s apartment. Belinda and Warren also left, returning later with gum, cigarettes, and a bottle of wine. At that time, Floyd Murray was upstairs with Fluker’s sleeping children. Dyer, Jackson, and Ario returned approximately midnight. The three went upstairs with Belinda Murray and Warren to Belinda’s bedroom, where Dyer, Jackson, and Ario again injected themselves with drugs. Dyer then laid down on Belinda’s bed, covered his eyes with his arm, and rested. Ario gave his .45 caliber gun to Belinda Murray, and she placed it in the closet. Warren left the apartment soon thereafter, and Jackson and Ario followed.
Dyer arose after about five minutes and appeared startled. He noticed that his rings were missing and asked Belinda Murray if his stepbrother Jackson had removed them from his fingers. Belinda told Dyer that she did not know, but said that Warren had been nearby when he fell asleep. Dyer concluded that Warren must have taken his rings. Dyer told Belinda to give him Ario’s gun, which he stuck inside his pants along with his own .38 caliber pistol. Dyer then asked Belinda to accompany him through the housing project in search of Warren so he could locate his missing rings.
Dyer conversed with Belinda Murray as they walked. He appeared angry, but not intoxicated. He told her that he was going to kill Warren if he found him that evening and if not, he was going to “whip his ass” once he did.
When Belinda Murray and Dyer returned, Belinda went upstairs while Dyer sat downstairs on the couch. Belinda heard a knock on the door and, looking out her bathroom window, saw Warren standing at the front door. Belinda rushed downstairs and found Dyer pistol-whipping Warren on the head with both guns. Warren’s face was bloody and he was almost unconscious. Dyer demanded that Warren return his rings. Warren denied having them and Dyer told him, “You better pray my brother has my rings.” At all times during the beating, Dyer appeared angered, but in control of himself.
Within minutes, Jackson and Ario arrived. Jackson asked Dyer what was the matter. Dyer, with a gun in each hand, pushed Jackson away. Jackson, upset by Dyer’s act, left the apartment. Belinda Murray and Fluker followed Jackson outside and quieted him down. When Jackson came back inside, Dyer gave him one of the guns and Jackson immediately became violent. He pushed both Belinda Murray and Fluker and told them not to move. Upon Dyer’s command, *932Ario searched Warren, but did not find Dyer’s rings. During the search, Dyer kept his gun pointed at Warren and told him he was “a dead man.”
Upon hearing Dyer’s threat, Ario told Dyer that if he killed one of them he would have to kill the others as well. Dyer replied, “Man, I’m not killing no babies.” Ario then went upstairs to get Floyd Murray. Jackson marched at gunpoint the four captives— Fluker, Warren, Belinda, and Floyd Murray — into the back seat of a car. Dyer joined Jackson and Ario in the front seat.
The four hostages urged whomever took the rings to return them. No one, however, admitted to having the rings. Jackson finally turned around, gun in hand, and ordered them to “shut up.” Ario said that they should “kill that bitch first,” referring to Belinda Murray. During the ride, Floyd Murray asked Dyer several times, ‘Why do you want to take me out?” Dyer told him to “shut up” and stuck his gun in Floyd’s- face.
After about ten minutes, the car stopped and Dyer said, “Get out.” Dyer pointed the .45 caliber weapon at the four hostages and instructed them to walk straight ahead. Jackson ordered them to lie face down on the ground. Before lying down, Belinda Murray saw that Dyer still had a gun.
After she lay down, Belinda looked up and could see “the fire coming” as the first shot was fired. She threw her arms up over her head and passed out.
Although ordered to lie face down, Floyd Murray remained on his knees. Warren (who had been a member of the National Rifle Association since age 13 and was very familiar with guns) then heard three shots from the .38 caliber revolver come from his left, where Belinda Murray was lying. He then heard scuffling noises, as if someone was being beaten. Someone said, “This bitch ain’t dead yet.” Warren heard a few more shots and heard someone say, “If she’s not dead now, she’ll be dead by morning.” Warren thought the additional shots also came from the .38 revolver.
Warren next heard shots from the .45 caliber gun, followed by more scuffling. He heard someone walk toward him, looked up, and saw Dyer holding the .45 about a foot away from Fluker. Dyer fired three shots; each time a bullet entered Fluker’s body, Warren “could feel her fluttering and jumping.”
Dyer then stepped in front of Warren, who got up on his knees. He pointed the gun at Warren’s head and fired. Warren flipped over backwards and, before losing consciousness, heard someone say, “If they’re not dead now, they’ll be dead by morning,” and someone else say, “check their pulse.”
When Belinda Murray regained consciousness, she felt someone taking her pulse and heard him say, “The bitch is not dead.” A gun was placed against her head and Belinda heard three clicks, but the gun did not fire. She “played dead” until Jackson, Dyer, and Ario left. None of them appeared intoxicated at any time during the evening.
Eventually, Belinda Murray managed to get up, locate a phone,' and contact an ambulance and the police. Warren also managed to flag down a police car and was taken to a hospital.
An autopsy of Floyd Murray’s body revealed four gunshot wounds to the head and shoulder, at least two of which were caused by .38 caliber bullets. An autopsy of Fluker’s body disclosed three gunshot wounds to the head and shoulder blade, at least one of which was from a .45 caliber gun and at least one from a .38 caliber gun.
A.
Dyer’s theory of defense was diminished capacity. Dyer did not deny or attempt to justify his actions. Instead, he claimed that his own mental faculties were impaired by his consumption of drugs and alcohol. Dyer testified that he snorted cocaine and drank wine and brandy with Jackson and Ario before they went to Belinda Murray’s apartment. At the house, Ario injected him with a combination of cocaine and heroin.
Dyer testified that when he left Belinda’s apartment with Jackson and Ario, they went to the home of Delphine “Dee” Dismuke, where Dyer smoked marijuana, snorted cocaine, and drank gin. According to Dyer, the *933three men then returned to Belinda’s house where Ario injected him again. Dyer testified that he fell asleep, and after he woke up, noticed that everyone had left and that his rings, money, and .38 caliber gun were missing. Dyer said he asked Belinda Murray what happened to his gun and whether his brother had his rings. She told him that she had put his gun in the closet with Ario’s and that she did not know whether Jackson had his rings. Dyer asked her who was standing over him when he fell asleep and she told him that it was Warren. After retrieving both guns, Dyer testified that he and Belinda Murray walked through the housing project looking for Warren, and soon returned when their search was fruitless.
Dyer testified that when Warren arrived at the Murray house, Belinda Murray opened the door and let him in. Dyer said that he asked Warren for his rings, they began arguing, and that Dyer began hitting Warren with the guns. Dyer admitted pistol-whipping Warren but testified that he was “confused ... hurt [and] mad” and that he “didn’t know ... what was actually going on.” Dyer remembered pointing the gun at Jackson and Ario and pushing them away when they walked in.
The next thing that Dyer said he recalled was sitting in Jackson’s ear with his head down, crying. He said that Jackson put his arms around Dyer and told him that it would “be cool.” Dyer remembered the car stopping, exiting the car, and hearing gun shots. He did not remember whether he fired any of the shots, but did not deny shooting anyone. When asked at trial if he killed anyone, Dyer said, “It’s possible. I had a gun. I don’t know.”
Dyer recalled being at a friend’s house the following morning, but could not remember the interim period very well. Dyer testified that he took some more cocaine at his friend’s house and then called his mother. She told him that Fluker and Floyd Murray were dead and that the police were looking for him. Over four months after the shootings, Dyer surrendered to the police.
Dyer’s primary witness at trial, Kate B. Yago, M.D., was certified as an expert in the area of drugs that adversely affect the brain. She opined that Dyer had been suffering from a drug overload at the time of the killings. Dr. Yago conceded that Dyer should have recalled certain events in light of his recollection of other events. Responding to a hypothetical question, Dr. Yago testified that a person such as Dyer “would have [had] to [have] be[en] clearheaded” to have acted the way he did. She was unable to name any drug-induced conditions that could account for Dyer’s selective memory loss, but indicated that the drugs Dyer ingested, in isolation, often cause loss of memory. When asked if she could think of any medical explanation for a hypothetical situation based on Dyer’s testimonial account of his mental state on the night of the killings, Dr. Yago testified, “If I am to believe your hypothetical, then I can’t.”
B.
The State presented no penalty-phase evidence, other than proof of Dyer’s prior robbery and burglary convictions. Dyer called co-workers, his mother, and a psychologist, Dr. Thomas Hilliard, to testify at the penalty phase.
Dr. Hilliard interviewed Dyer three times. He found Dyer to be a polite, low-keyed, soft-spoken, and a cooperative man who was not evasive or malingering. Dyer was coherent, alert, and well-oriented, except for his “spotty, incomplete and confused” memory of the night of the shootings. Hilliard testified that he detected signs of “depression, anxiety and tension.” Several times during the interviews, Dyer broke down and sobbed for a while before regaining his composure. Dr. Hilliard told the jury about Dyer’s personal history, from infancy to the time of the killings.
Two of Dyer’s co-workers testified about Dyer’s dependable work habits as a bus driver and about his ability to work well with children. Dyer’s mother testified about his childhood and character.
We review de novo the denial of Dyer’s petition for writ of habeas corpus. Bonin v. Calderon, 59 F.3d 815, 823 (9th Cir.) (Bonin), cert. denied, — U.S. -, 116 S.Ct. 718, 133 L.Ed.2d 671 (1996). However, find*934ings of fact made by the district court underlying its denial of Dyer’s petition are reviewed for clear error. Id.
During the pendency of Dyer’s appeal, Congress enacted the Antiterrorism and Effective Death Penalty Act of 1996(Act), 142 Cong.Ree. H3305-01 (1996) (to be codified at 28 U.S.C. § 2261). The Act does not retroactively apply to Dyer’s appeal. Jeffries v. Wood, 103 F.3d 827 (9th Cir.1996) (en banc).
II
Dyer contends that the presence of Jessica Freeland on the jury deprived him of his constitutional right to an impartial jury. He argues that Freeland was dishonest during voir dire, intentionally failing to disclose certain relevant information. Alternatively, Dyer argues that even if Freeland’s false answers were given in good faith, we should presume Freeland was biased.
A
Prior to jury selection for Dyer’s trial, each prospective juror was given written questions about employment, residence, family, experience with criminal proceedings, pri- or jury service, and prior contact with law enforcement personnel. When asked orally during voir dire, Freeland answered, “No” to the following questions:
13. Have you or any of your relatives or close friends ever been the victim of any type of crime?
15. Have you or any of your relatives or close friends ever been accused of any offense other than traffic cases?
After the jury returned its guilt-phase verdict, Dyer learned that Freeland’s brother Richard had been killed five to ten years earlier. The trial court called Freeland into chambers with counsel and conducted a hearing in absence of the jury. Freeland admitted that her brother had been shot and killed approximately five years earlier. She said she did not know whether any legal proceedings were instituted against “the man that accidentally shot him.” Freeland explained that she answered “no” to Question 13 because she believed her brother’s death was an accident and not a crime. She stated that she could be fair in Dyer’s case.
The trial court found no lack of candor in Freeland’s answers and denied Dyer’s motion for a mistrial. In rejecting Dyer’s subsequent motion for a new trial, the trial court found that the questions were ambiguous and that Freeland’s responses were inadvertent.
On direct appeal, the California Supreme Court agreed that the questions were ambiguous and found no evidence that Freeland was lying when she said that no member of her family had been a crime victim. People v. Dyer, 45 Cal.3d 26, 58-59, 246 Cal.Rptr. 209, 753 P.2d 1 (Dyer), cert. denied, 488 U.S. 934, 109 S.Ct. 330, 102 L.Ed.2d 347 (1988).
The district court conducted an evidentiary hearing on the issue of Freeland’s bias, at which Dyer presented the. following evidence to support his contention that Freeland’s answer to Question 13 was dishonest: (1) Free-land was close to Richard and lived with him and her mother at the time Richard was killed; (2) Richard’s death caused the family pain; (3) Freeland’s mother testified against Richard’s killer in criminal proceedings; and (4) Freeland’s family filed a wrongful-death action against Richard’s killer and recovered $15,000.
Dyer also presented evidence at the hearing that Freeland’s responses during voir dire failed to reveal the following: (1) while lying on a couch, she had been attacked by her young cousin, who had a knife, but she was not hurt; (2) her father had been arrested for kidnapping his children; (3) her brother and her uncle had both been accused of crimes; (4) her family home and her car had been broken into and burglarized on multiple occasions; and (5) her former husband had been arrested for rape.
After reviewing this additional evidence, the district court refused to disrupt the state courts’ findings regarding Freeland’s honesty and refused to presume that Freeland was biased.
B.
The Sixth Amendment “guarantees to the criminally accused a fair trial by a *935panel of impartial, ‘indifferent’ jurors.” Irvin v. Dowd, 366 U.S. 717, 722, 81 S.Ct. 1639, 1642, 6 L.Ed.2d 751 (1961). “Even if only one juror is unduly biased or prejudiced, the defendant is denied his constitutional right to an impartial jury.” Tinsley v. Borg, 895 F.2d 520, 523-24 (9th Cir.1990) (Tinsley) (internal quotations omitted), cert. denied, 498 U.S. 1091, 111 S.Ct. 974, 112 L.Ed.2d 1059 (1991).
The Constitution “does not require a new trial every time a juror has been placed in a potentially compromising situation.” Smith v. Phillips, 455 U.S. 209, 217, 102 S.Ct. 940, 946, 71 L.Ed.2d 78 (1982) 0Smith). Due process only requires that the defendant be tried by “a jury capable and willing to decide the case solely on the evidence before it, and a trial judge ever watchful to prevent prejudicial occurrences and to determine the effect of such occurrences when they happen.” Id.
Dyer is entitled to a new trial if he “first demonstrate[s] that a juror failed to answer honestly a material question on voir dire, and then further show[s] that a correct response would have provided a valid basis for a challenge for cause.” McDonough Power Equipment v. Greenwood, 464 U.S. 548, 556, 104 S.Ct. 845, 849, 78 L.Ed.2d 663 (1984) (McDonough); United States v. Edmond, 43 F.3d 472, 474 & n. 1 (9th Cir.1994) (holding that a showing of juror dishonesty is a necessary predicate to obtaining a new trial);1 Tinsley, 895 F.2d at 524-25 (applying standard to claim of impartiality on habeas). Thus, we must begin by asking whether Dyer has shown that Freeland lied when she answered “no” to two questions on voir dire.
l.
When reviewing a petition for habeas corpus, we must, absent one of eight statutory exceptions, presume the correctness of state court findings of “basic, primary, or historical facts.” Thompson v. Keohane, — U.S. -, -, 116 S.Ct. 457, 464, 133 L.Ed.2d 383 (1995) (Thompson), quoting Townsend v. Sain, 372 U.S. 293, 309 n. 6, 83 S.Ct. 745, 755 n. 6, 9 L.Ed.2d 770 (1963) Tinsley, 895 F.2d at 525; see 28 U.S.C. § 2254(d). Because “resolution depends heavily on the trial court’s appraisal of witness credibility and demeanor,” Thompson, — U.S. at -, 116 S.Ct. at 465, juror impartiality is a factual issue that falls within the statutory presumption of correctness. Id.; Wainwright v. Witt, 469 U.S. 412, 429, 105 S.Ct. 844, 854-55, 83 L.Ed.2d 841 (1985) (Witt); see also Miller v. Fenton, 474 U.S. 104, 114, 106 S.Ct. 445, 452, 88 L.Ed.2d 405 (1985) (“[T]he state trial judge is in a position to assess juror bias that is far superior to that of federal judges reviewing an application for a writ of habeas corpus.”); Knaubert v. Goldsmith, 791 F.2d 722, 727 (9th Cir.) (Knaubert) (“We can think of no sort of factual finding that is more appropriate for deferential treatment than is a state court’s credibility determination.”), cert. denied, 479 U.S. 867, 107 S.Ct. 228, 93 L.Ed.2d 155 (1986). A trial court decision that a juror is impartial is to be given “presumptive weight,” Thompson, — U.S. at -, 116 S.Ct. at 465, and “special deference.” Patton v. Yount, 467 U.S. 1025, 1038, 104 S.Ct. 2885, 2892, 81 L.Ed.2d 847 (1984) (Patton).
The state trial court made findings that Freeland’s answers on voir dire were not dishonest or intentionally misleading. At the in camera hearing, the trial court had an *936adequate opportunity to witness Freeland’s demeanor and questioned her about her understanding of the circumstances surrounding her brother’s death and whether she believed it would affect her partiality. The trial court refused to “characterize anything [Freeland] did or did not do as demonstrating any lack of candor.” Also, the trial court found that Freeland’s allegedly false answers to the two voir dire questions at issue were “inadvertent” and were given in “good faith.” We will give presumptive weight to these findings of Freeland’s impartiality unless a statutory exception exists.
Dyer argues that the statutory presumption should not apply because material facts were not developed adequately at the state court hearings. 28 U.S.C. § 2254(d)(3). Alternatively, he argues that if the presumption applies, he has established by convincing evidence that the state court determinations regarding Freeland’s honesty were erroneous. 28 U.S.C. § 2254(d).
a.
Dyer contends that material facts about Richard’s death were not developed adequately at the trial court proceeding. However, the trial court found that Freeland honestly believed that her brother’s death was an accident, and therefore not a crime. This finding is not inconsistent with Freeland and Richard’s closeness. That Richard’s death seriously affected Freeland and her family is also not inconsistent with Free-land’s then belief that her brother was accidentally killed. Dyer alleges that the state court and state supreme court did not know or did not consider that Freeland’s mother testified against Richard’s killer in criminal proceedings. Yet Dyer does not show that Freeland knew about this testimony, nor does this fact necessarily establish that she believed Richard’s killer had committed a crime. Dyer also alleges that the trial court was unaware that Freeland’s family instituted a wrongful death suit against Richard’s killer, and that the family received civil restitution from the killer. But the state supreme court was aware of the lawsuit and settlement and upheld the trial court’s finding of impartiality. Dyer, 45 Cal.3d at 59, 246 CaLRptr. 209, 753 P.2d 1. Knowledge of a wrongful death action or restitution would not be inconsistent with Freeland’s belief that her brother was accidently killed. We therefore refuse to disrupt the state courts’ determination that Freeland answered honestly based on evidence unknown to the state trial judge that is wholly consistent with such a finding.
But Dyer contends that the trial court was unaware that Freeland failed to reveal that she was “attacked” by her cousin, that her father had been arrested for kidnapping Freeland and her siblings, that her uncle had been arrested for murder, that her brother had been arrested on drug charges, that Freeland’s ears.and homes had been burglarized on numerous occasions, and that her former husband had been arrested for rape. As to each of these additional facts, Freeland has since explained why she originally failed to disclose. Although not present at the district court’s evidentiary hearing, she testified at her prehearing deposition that at the time of voir dire, she did not know about her brother’s or estranged husband’s arrests. She considered her uncle too remote to be family. She regarded her father’s arrest for kidnapping and her cousin’s assault as remote, apparently inconsequential events. She did not consider that burglaries of her homes and cars rendered her a “victim of a crime.” She stated that, “I was not attempting to be deceptive. I’m just saying it was not on my mind, Yeah, burglary, I’m the victim of a crime.’ [ ] I read ... “victim of a crime,’ ... like victim of some violent attack or something like that. Burglaries [are] not a big issue with people in Oakland.” The district court explicitly credited Freeland’s testimony and found that the new evidence did not detract from the state courts’ findings about Freeland’s credibility. This finding is not clearly erroneous.
The dissent would not defer to the state trial court’s and district court’s findings of fact because “the [state] court did not adequately develop the material facts.” Dissent at 955; see also id. at 956 (“[n]or did the court develop the evidence of the sexual assault and multiple burglaries committed against Freeland, or the serious crimes *937charged against her several immediate relatives”). Of course, we do not place the onus on the trial court to unearth every bit of evidence that might indicate that a particular juror is biased. Rather, “it is the adversary seeking exclusion who must demonstrate, through questioning, that the potential juror lacks impartiality.” Witt, 469 U.S. at 423, 105 S.Ct. at 852; see also Smith, 455 U.S. at 215, 102 S.Ct. 940, 944-45, 71 L.Ed.2d 78 (Supreme “Court has long held that the remedy for allegations of juror partiality is a hearing in which the defendant has the opportunity to prove actual bias”). In fact, added facts were placed before the state trial judge when Dyer moved for a new trial and his counsel filed a declaration, asserting that the killer of Freeland’s brother was convicted of voluntary manslaughter. The motion argued, as the dissent does now, that Free-land’s “reasoning is simply incredible.”
In any event, we are faced with not only state court findings of impartiality, but with district court findings that are based on the additional facts that Dyer has since proffered and on which the dissent focuses its attention. As the district court found, none of these additional facts provides any reason to disturb the state courts’ finding that Free-land was honest in her responses. See Nix v. Williams, 467 U.S. 431, 449-50, 104 S.Ct. 2501, 2511-12, 81 L.Ed.2d 377 (1984) (newly discovered evidence failed to demonstrate that facts were not adequately developed in state court). Dyer complains that the district court relied only on Freeland’s deposition testimony and that no court has confronted her with all of her omissions and determined that she was dishonest. However, none of the district court’s findings as to Freeland’s credibility is clearly erroneous. Therefore, these additional facts should not destroy the presumption that the state courts’ findings of fact are correct. See Bonin, 59 F.3d at 823.
b.
If the statutory presumption in favor of crediting the trial court’s factual findings applies, Dyer argues alternatively that he has presented convincing evidence to rebut the state courts’ findings of Freeland’s honesty. Although the number of crimes committed by members of her family seems high, and the number of incidents in which she or members of her family were victims of crimes also seems high, these facts above do not establish that Freeland was dishonest. Freeland is apparently from a crime-ridden community — a fact which plausibly both affects her understanding of what qualifies as a crime and influenced her answers to Questions 13 and 15. Both the trial court and state supreme court found that the voir dire questions were ambiguous and that Free-land’s responses at the in camera hearing and at her deposition were honest. See United States v. Nickell, 883 F.2d 824, 827 (9th Cir.1989) (where juror’s answer is consistent with one interpretation of ambiguous question, there is no basis for finding dishonesty). The record as a whole, including Freeland’s deposition testimony and her responses at the in camera hearing, is adequate to support the findings that she was not being dishonest during voir dire. See McDonough, 464 U.S. at 556, 104 S.Ct. at 849 (“The motives for concealing information may vary, but only those reasons that affect a juror’s impartiality can truly be said to affect the fairness of a trial.”).
The dissent rejects the state court’s factual findings as to Freeland’s honesty and would instead find that Freeland’s responses were “patently implausible.” Dissent at 953. The dissent’s keystone is that “Freeland lied,” and that her “blatant lies demonstrate her actual bias.” Id. at 951-952. But did she lie? Our time-tested judicial system relies heavily on the trial judge to make this determination. Of course, one may assume a fact from the cold, sterile reporter’s transcript, but experience has demonstrated that the trial judge, using all the senses (including even voice inflections), is in the best position to determine credibility. All trial judges have had that experience — and appellate judges properly defer to the factual finding of credibility. Indeed, on issues of credibility, we give special deference. Knaubert, 791 F.2d at 727.
We, therefore, are unwilling to second-guess the state judge, who had ample oppor*938tunity to view Freeland’s demeanor and assess her responses. The record certainly supports the trial court’s assessment of Free-land’s honesty on the subject of her brother’s death. The very first question posed to Freeland at the hearing was whether “at any time in the last five or ten years ha[s] any member of [her] family or former member of [her] family, or anyone who was ever related to [her] [been] the victim of a homicide.” When asked this different, direct, pointed question, Freeland answered, “Yes, my brother.” When asked why this event did not stop her from answering “no” to Question 13, Freeland’s answer was plausible. The dissent would refind the facts and hold that her answer “defie[d] common sense.” Dissent at 953. We, on the other hand, can imagine a number of sensible reasons to explain Freeland’s belief. For example, her father may have withheld the truth to protect Freeland, or despite persuasive evidence to the contrary, Freeland may have been willfully blind. But we need not delve into Freeland’s psyche. Rather, the trial court saw Freeland testify and simply did not believe that she lied. See Dennis v. United States, 339 U.S. 162, 171, 70 S.Ct. 519, 523, 94 L.Ed. 734 (1950) (“One may not know or altogether understand the imponderables which cause one to think what he thinks, but surely one who is trying as an honest man to live up to the sanctity of his oath is well qualified to say whether he has an unbiased mind in a certain matter.”). Simply put, while there are substantial questions raised as to her credibility, the findings by the state trial court, added to by the findings of the district judge, have not been demonstrated by Dyer to be clearly erroneous — given the special credibility deference we are required to apply: she believed what she said was true at that time.
2.
We add, without extensive elaboration, that there is a second burden placed on Dyer to receive habeas corpus relief on this issue. Dyer must show that a “correct” response would have provided a valid basis for a challenge for cause. McDonough, 464 U.S. at 556, 104 S.Ct. at 850. To have the trial court excuse Freeland for cause, Dyer must demonstrate to the trial judge that Freeland could not be a fair juror. That is, regardless of past experience, could she be a fair juror and decide the case on the facts found to be true and the law provided by the court? See Patton, 467 U.S. at 1035, 104 S.Ct. at 2890-91 (“The relevant question is ... whether the juror[ ] ... had such fixed opinions that [she] could not judge impartially the guilt of the defendant.”); United States v. Quintero-Barraza, 78 F.3d 1344, 1349-50 (9th Cir.) (quoting Patton), cert. denied, — U.S.-, 117 S.Ct. 135, 136 L.Ed.2d 83 (1996).
The state trial judge found she could. The district court’s findings uphold the state court’s finding that Freeland could be fair. In effect, these courts found Freeland was “capable and willing to decide the case solely on the evidence” presented. Smith, 455 U.S. at 217, 102 S.Ct. at 946. However, this issue was not argued before us, and we take no position on it. Because of our holding in part II.B.l., it is unnecessary for us to consider it.
C.
Dyer also argues that even if Free-land did not withhold information intentionally, we should presume or imply bias based on the circumstances. The Supreme Court has never explicitly held that we may infer or presume bias based on the totality of the circumstances. We are extremely reluctant to do so, and we will presume bias only in the rarest and most extraordinary circumstances. Tinsley, 895 F.2d at 527; see also McDonough, 464 U.S. at 556-57, 104 S.Ct. at 850-51 (Blackmun, J., concurring); id. at 558, 104 S.Ct. at 851 (Brennan, J., concurring).
In only two cases have we held that “bias could be implied or presumed from the ‘potential for substantial emotional involvement, adversely affecting impartiality,’ inherent in certain relationships.” Tinsley, 895 F.2d at 527, quoting United States v. Allsup, 566 F.2d 68, 71 (9th Cir.1977). In Allsup, we held that two jurors in a bank robbery trial were partial despite their protestations of impartiality and the district court’s finding of impartiality. Allsup presumed bias because the jurors were employees of a different branch of a bank that was robbed. 566 F.2d *939at 71. In addition, the jurors’ employment relationship with the bank and their “reasonable apprehension of violence” due to the risk of violence from bank robbers created a “substantial probability” that the jurors could not be impartial. Id. at 71-72. Similarly, in United States v. Eubanks, 591 F.2d 513 (9th Cir.1979), a heroin conspiracy trial, a juror did not disclose on voir dire that two of his children were in prison for heroin-related crimes. Id. at 516. We presumed that the juror was biased because of his children’s involvement with heroin. Id. at 517.
Dyer insists that his is an extreme and extraordinary case that requires us to presume bias. He urges us to presume that Freeland was partial because she and so many of her relatives have either been convicted of crimes or been victims. Dyer especially urges a finding of bias because Free-land’s brother was shot several times in the head, just as the victims in this case were. We recognize that on rare occasions, “[cjourts have been willing to presume bias where a juror or his close relatives have been personally involved in a situation involving a similar fact pattern.” Tinsley, 895 F.2d at 528 (citing cases). However, here we accept the trial court finding that Freeland honestly believed that her brother had been killed accidentally. In addition, we do not believe that one characteristic of the two events — the similar manner of death — renders the case extraordinary or extreme.
We also recognize that, at first glance, it seems extraordinary that Freeland has experienced such tragedies. However, considering the alleged rate of crime in Freeland’s neighborhood, her situation as to much of this background is not so surprising or extraordinary. ’ Indeed, Freeland has experienced crime from both sides — as a victim and as the family member of criminals. We cannot say that there was an inherent “potential for substantial emotional involvement, adversely affecting impartiality.” Id. at 527 (internal quotation omitted). Freeland herself testified that she had forgotten about most of the crimes in her past and that she had “a ton of relatives” who “have done things.” Although her brother was killed by a gunshot wound to the head, which she believed was accidental, she also has relatives who have been convicted of crimes. Thus, Dyer has not shown that she would have been biased for or against him. See Romano v. Oklahoma, 512 U.S. 1, 11-13, 114 S.Ct. 2004, 2012-13, 129 L.Ed.2d 1 (1994) (Romano ) (because erroneously admitted evidence could have made jurors more inclined to impose death, or less inclined to impose death, court would not find prejudice based on mere speculation). We therefore will not presume that because Freeland may have associated or lived with people who have committed crimes, or that because she has been a victim of crimes, she was presumably biased against Dyer.
The dissent would imply bias based on the similarities between Freeland’s brother’s death and the facts surrounding Dyer’s crimes. However, as we explained earlier, we presume that the state court’s findings are correct that Freeland did not understand or know the facts surrounding her brother’s death when she served as a juror. Thus, even if these circumstances were sufficiently extraordinary to indicate that Freeland might be biased, we would not imply bias where we have already upheld state court findings that show that Freeland was not aware of the similarities.
Ill
Dyer next contends that his trial attorney, John Burris, provided ineffective assistance for failing to investigate, obtain, and present evidence of Dyer’s use of phencyclidine (POP) before the murders, Dyer’s psychological and social history, and Dyer’s organic brain damage. Dyer also argues that Burris failed to investigate the circumstances of his prior robbery conviction and was ineffective at the penalty phase for failing to contest the facts underlying the robbery conviction. Dyer’s claims of ineffective assistance of counsel present mixed questions of law and fact that we review de novo. McKenna v. McDaniel, 65 F.3d 1483, 1490 (9th Cir.1995), cert. denied, — U.S.-, 116 S.Ct. 1451, 134 L.Ed.2d 570 (1996).
To establish that his trial counsel was constitutionally defective, Dyer must demonstrate “(1) that counsel made errors so seri*940ous that counsel was not functioning as the counsel guaranteed the defendant by the Sixth Amendment, and (2) that the deficient performance prejudiced the defense.” Bonin, 59 F.3d at 833 (internal quotations and citations omitted). The ultimate question is whether Burris’s “representation fell below an objective standard of reasonableness.” Strickland v. Washington, 466 U.S. 668, 688, 104 S.Ct. 2052, 80 L.Ed.2d 674 (1984) (Strickland ). We must “indulge a strong presumption that counsel’s conduct falls within the wide range of reasonable professional assistance.” Id. at 689, 104 S.Ct. at 2065. Our review of counsel’s performance under Strickland is extremely limited:
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 ask only whether some reasonable lawyer at the trial could have acted, in the circumstances, as defense counsel acted at trial.
White v. Singletary, 972 F.2d 1218, 1220 (11th Cir.1992), cert. denied, — U.S.-, 115 S.Ct. 2008, 131 L.Ed.2d 1008 (1995). Thus, “[w]e will neither second-guess counsel’s decisions, nor apply the fabled twenty-twenty vision of hindsight.” Campbell v. Wood, 18 F.3d 662, 673 (9th Cir.) (en banc), cert. denied, 511 U.S. 1119, 114 S.Ct. 2125, 128 L.Ed.2d 682 (1994).
“[Strategic choices made after thorough investigation of law and facts relevant to plausible options are virtually unchallengeable; and strategic choices made after less than complete investigation are reasonable precisely to the extent that reasonable professional judgments support the limitations on investigation.” Strickland, 466 U.S. at 690-91, 104 S.Ct. at 2066. A “particular decision not to investigate must be directly assessed for reasonableness in all the circumstances, applying a heavy measure of deference to counsel’s judgments.” Id. at 691,104 S.Ct. at 2066.
To make out a claim, Dyer must establish prejudice, demonstrating that there is a “reasonable probability that, but for counsel’s errors, the result of the proceeding would have been different.” Bonin, 59 F.3d at 833 (citations omitted).
A.
Dyer contends that all of his actions on the night of the murders could have been explained with testimony that Dyer had ingested PCP and that he was prejudiced because Burris failed to investigate and present evidence to this effect. Such evidence, Dyer asserts, would have bolstered his diminished capacity defense and would have amounted to mitigating evidence at the penalty phase that reasonably would have led to a life sentence.
1.
Dyer argues that Burris’s investigation into Dyer’s possible ingestion of PCP was inadequate. Dyer has now come forward with depositions from three witnesses — Sandra Collins, Roger Dismuke, and Charles Howard — who say they saw Dyer smoke “sherm” (a street name for cigarettes laced with PCP) at Dismuke’s party on the night of the murders. In addition, Dr. Yago, the defense expert at Dyer’s trial who discussed the general effects of cocaine, heroin, amphetamines, methamphetamines, and combinations of these drugs, such as speedballs, now asserts that had she known that Dyer may have ingested PCP, she would have testified differently. Dr. Yago now contends that Dyer’s ingestion of PCP on the night of the murders “could explain” his alleged cognitive impairments and memory lapses.
Despite the medical evidence that Dyer now proffers, and despite the depositions of witnesses who now testify that he smoked “sherm,” we cannot say that Burris’s investigation was constitutionally ineffective. Burris stated that he knew that some of those attending Dismuke’s party had smoked sherm because Dyer knew and told him that PCP was being used at the party. However, Dyer never told Burris that he had smoked sherm. None of the doctors who interviewed or examined Dyer before trial indicated that Dyer had admitted smoking sherm. In fact, no one with whom Burris or his assistants spoke stated that Dyer had mentioned smoking PCP-laced cigarettes.
*941Despite the lack of credible or corroborating evidence that Dyer himself ingested PCP, Burris stated that he explored the possibility that Dyer had consumed that drug in addition to the others. Burris sent an investigator to interview Dismuke. He informed the investigator that Dyer “consumed alcohol and smoked marijuana or dope at [Dismuke’s] home.” Burris testified that he “would consider smoking a sherm as dope.” Although the investigator failed to locate Dismuke, Burris’s law clerk eventually found her. Based on the clerk’s interview, which may or may not have included a discussion of PCP, Burris decided not to interview Dismuke further and decided not to call her to testify.
Based on the evidence before us, we cannot say that Burris’s investigation was inadequate. Although he knew that PCP was consumed at Dismuke’s party, Burris had no credible evidence from Dyer or anyone else that Dyer himself had ingested PCP. No expert at the time of trial associated Dyer’s behavior with possible ingestion of PCP. Thus, simply because Burris was aware of possible PCP use but did not attempt to have witnesses interviewed or locate additional evidence that would corroborate his suspicions, his investigation was not deficient. Even if Burris was not fully educated as to the subtle differences between the effects of PCP and the effects of other drugs, this lack of knowledge is irrelevant. It was the lack of credible evidence that led Burris to the decision not to pursue Dyer’s possible PCP use. See Wade v. Calderon, 29 F.3d 1312, 1318-19 (9th Cir.1994) (Wade) (not ineffective assistance where counsel decided not to present evidence of petitioner’s possible PCP use because of lack of evidence and because of his belief that jury would use such evidence only in aggravation), cert. denied, 513 U.S. 1120, 115 S.Ct. 923, 130 L.Ed.2d 802 (1995).
Because Burris, after a reasonable initial investigation, was unable to locate credible evidence that would have supported a PCP theory, his tactical decision not to investigate further was also reasonable. See Hensley v. Crist, 67 F.3d 181, 185 (9th Cir.1995) (Hensley) (“Tactical decisions that are not objectively unreasonable do not constitute ineffective assistance of counsel.”); Wade, 29 F.3d at 1319. Rather, “the wholly unremarkable fact [is] that with the luxury of time and the opportunity to focus resources on specific parts of a made record, post-conviction counsel will inevitably identify shortcomings in the performance of prior counsel.” Waters v. Thomas, 46 F.3d 1506, 1514 (11th Cir.) (en banc) (Waters), cert. denied, — U.S.-, 116 S.Ct. 160, 133 L.Ed.2d 103 (1995). The fact that Dyer can now proffer evidence that he ingested PCP does not change the tactical nature of Burris’s reasonable decision to utilize his limited resources elsewhere.
For the same reasons, Burris’s failure to present evidence of PCP use at the penalty stage was also reasonable. Because the jury rejected his diminished-capacity defense at trial, Burris reasonably decided to present a positive portrait of Dyer at the penalty phase. Burris wanted to downplay the influence of drugs in order to avoid suggesting that Dyer acted totally irresponsibly. This decision was tactical and reasonable.
2.
Even assuming that Burris’s initial investigation into Dyer’s ingestion of PCP was inadequate, Dyer has not proved that he was prejudiced by such an error. It is not reasonably probable that the outcome of Dyer’s trial would have been different had Burris investigated further.
First, Dyer has failed to show that had Burris investigated, he would have uncovered credible evidence that would have strengthened Dyer’s case. The present cooperation of Roger Dismuke and Howard is in bold contrast with their response at trial. Roger Dismuke indicated at the time of trial that he would not testify on Dyer’s behalf. Burris’s law clerk did contact Howard, who at the time agreed to keep Burris informed of any helpful information. Dyer has not shown that had Burris investigated Howard further, Howard would have revealed anything that might have helped Dyer at trial. In addition, at the time of the offense, Collins was fifteen, and it has not been demonstrated that Dyer’s case would have been strengthened had a fifteen-year-old testified that Dyer shared PCP-laced cigarettes with her. Further*942more, testimony from the witnesses would have revealed additional inconsistencies. Collins, Howard, and Roger Dismuke disagree as to whether Dyer knew he was smoking PCP. They also disagree as to whether sherm has a distinctive smell that would alert a smoker as to what he was smoking.
The dissent points to a list of additional witnesses, including Dyer himself who, if investigated and called to testify, together would have established that Dyer used PCP. Dissent at 958-959. However, there is no indication that Dyer remembered taking PCP; thus, he could not and did not testify to having done so. Dr. David Smith’s testimony at the district court’s evidentiary hearing does not reliably indicate that Dyer ingested PCP. Compare id. Rather, Dr. Smith ambiguously testified that Dyer may have told him that “he thought he had taken — gotten PCP some way or another.” In fact, Buiiis testified at the district court’s evidentiary hearing that “[t]he reason why I didn’t follow up with [Dr. Smith] is because he told me that he did not think that I had a very good case in order to build a diminished capacity defense around the drugs that [ ] Mr. Dyer had taken.” Thus, even if Dr. Smith were aware that Dyer may have ingested PCP, he did not believe that it was strategically wise to rely on a diminished capacity defense. Burris disagreed and sought another opinion. Dyer has not shown that had Burris pushed Dr. Smith, Smith would have changed his opinion as to proper trial strategy and would have emphasized that Dyer may have ingested PCP. Furthermore, like Roger Dismuke and Howard, Delphine Dismuke was less than cooperative when Burris’s law clerk interviewed her. Even presuming that she would have cooperated had Burris investigated further, her testimony would have contradicted the testimony from Howard and Collins. Delphine Dismuke testified at the evidentiary hearing that Dyer was uncharacteristically aggressive, while Howard and Collins noticed nothing unusual.
Second, not only would further investigation have proved futile, but the evidence Dyer now proffers regarding the effects of PCP are mostly cumulative of the effects of the other drugs that he did admit to consuming. See United States v. Schaflander, 743 F.2d 714, 718-19 (9th Cir.1984) (Schaflander ) (failure to present cumulative testimony does not show prejudicial ineffective assistance), cert. denied, 470 U.S. 1058, 105 S.Ct. 1772, 84 L.Ed.2d 832 (1985). Dr. Yago’s declaration catalogs the range of physical and psychological effects of PCP:
Physical effects can include pupillary constriction, blurred vision, increased blood pressure and heart rate, sweating, nausea, and vomiting. PCP can cause depersonalization (feeling as if watching oneself from outside), agitation, disorganization of thought processes, visual and auditory distortions, intense feelings of alienation and paranoia, catatonic rigidity, mutism, and acute psychosis.
In addition, Dr. Yago now explains that a person intoxicated with PCP may engage in a series of acts without judgment or reasoning, may engage in psychotic behavior, and may engage in random, detached, inappropriate violent acts. She states that PCP “could explain” Dyer’s ability to sleep for a short period despite ingesting numerous stimulants and that it “could explain” his partial amnesia and goal-oriented behavior.
At trial, Dr. Yago testified that many of these same effects could have been caused by cocaine, heroin, amphetamines, methamphetamines, or a combination of these substances. Cocaine, she testified, can cause increased blood pressure, an increased heart rate, a sense of being hot, “a feeling as if one wants to move around, being more active, pacing back and forth, anxious,” flu-like symptoms, confusion, irrational paranoia, and extreme violence. She testified that heroin is a sedative that can cause a person to “nod off.” Amphetamines, she testified, can cause paranoia, confusion, disorientation, impaired perception, delirium, and memory loss. She testified that combining drugs can cause auditory and visual distortions, spontaneous aggression, and temporary periods of deep sleep. Dr. Yago also testified that what could appear as goal-oriented behavior could actually be based on psychotic thought processes.
*943At most, then, had Dr. Yago known that Dyer may have ingested PCP, and had Burris been able to produce credible evidence that Dyer had ingested PCP, Dr. Yago might have been better able to account for Dyer’s goal-oriented behavior and selective memory loss. Not only has Dyer failed to show that evidence of his allegéd PCP use should have been uncovered, but he has faded to demonstrate that a fuller account of his alleged behavior would have led to a different result. Thus, Burris’s failure to investigate and discover evidence that Dyer used PCP, and his failure to present such evidence to Dr. Yago for her analysis, did not prejudice Dyer.
B.
Next, Dyer alleges that Burris was ineffective for failing to investigate, obtain, and present additional evidence of Dyer’s psychological and social history. Dyer catalogs a number of facts about his past that Burris failed to discover and argues that Burris’s mitigation case was therefore unconstitutionally inadequate.
We have held defense counsel’s performance ineffective where counsel presents absolutely no mitigating evidence in a case where substantial evidence was available. Mak v. Blodgett, 970 F.2d 614, 619 (9th Cir. 1992), cert. denied, 507 U.S. 951, 113 S.Ct. 1363, 122 L.Ed.2d 742 (1993). However, counsel's decision not to conduct a particular investigation does not render performance defective where the decision is reasonably justifiable. Strickland, 466 U.S. at 691, 104 S.Ct. at 2066-67. We have never held that counsel has a duty to uncover every aspect of a defendant’s past and to present all evidence that might bolster a defendant’s mitigation case. Rather, trial counsel’s resources are limited and the strategic decision to emphasize certain aspects of a defendant’s background at the expense of investigating others is both reasonable and wholly acceptable. See Waters, 46 F.3d at 1514.
Here, Burris did present substantial evidence of Dyer’s psychological and social history. Dr. Hilliard conducted psychological tests, interviewed Dyer three times, and interviewed Dyer’s mother and co-workers. Dr. Hilliard, Dyer’s mother, and two coworkers all testified during the penalty phase. Dr. Hilliard obtained a complete history in which he traced Dyer’s development from birth until the time of the murders. As the district court recognized, the jury heard, among other things, that Dyer was well-behaved, nonviolent, and a peacemaker; that he helped his mother around the house from a very young age and enjoyed skating and boxing; that he stammered, had academic difficulties, and was teased as a child; that his mother was only fifteen when he was born and that she relocated without him on two occasions; that he grew up in overcrowded housing projects with his grandmother and had no father figure; and that he felt remorse about the offense.
Dyer’s newly proffered evidence, largely cumulative of the information that was actually presented to the jury, does not establish Burris’s ineffectiveness. Schaflander, 743 F.2d at 718. The prosecution did not challenge any of the background information Burris presented, and Burris did not believe that it was necessary to present additional evidence. This was a reasonable tactical decision. See Hensley, 67 F.3d at 185; Mills v. Singletary, 63 F.3d 999, 1024 (11th Cir.1995) (“counsel is not required indiscriminately to present evidence”), cert. denied, — U.S. -, 116 S.Ct. 1837, 134 L.Ed.2d 940 (1996).
C.
Dyer also contends that Burris was ineffective for failing to investigate and present evidence that Dyer suffers from organic brain damage. The record indicates that Dyer told Burris that he had been in a car accident six to eight weeks before the offense. Burris also knew that Dyer had hit his head in this accident and had been hospitalized. Burris reviewed Dyer’s hospital records and had his hospital x-rays reviewed by Dr. Ramona Toscoe, who indicated that there was no apparent structural damage.
The record also indicates that Burris knew that Dyer had been hit on the head with a bottle as a small boy and that Dyer had boxed for a number of years. Burris had Drs. Yago, Hilliard, and Smith examine Dyer. Dr. Yago conducted a psychiatric eval*944nation and Dr. Hilliard performed psychological tests. None of their reports indicated that Dyer suffered from brain damage.
Dyer essentially argues Burris was ineffective for failing to hire a neurologist or neuropsychologist to conduct further examinations and tests. But Burris conducted no further investigation into possible brain damage because, after examining hospital records and x-rays, Dr. Toscoe discovered no structural abnormality. Burris was entitled to rely on the assessments of Drs. Toscoe, Hilliard, Yago, and Smith, see Hendricks v. Calderon, 70 F.3d 1032, 1039 (9th Cir.1995), cert. denied, — U.S. -, 116 S.Ct. 1335, 134 L.Ed.2d 485 (1996), and his decision to focus his efforts elsewhere was also reasonable.
D.
Dyer contends that Burris was ineffective for faffing to consider the possibility that a penalty-phase stipulation to a firearm enhancement could be used as evidence in aggravation.
Before trial, Dyer admitted that he had been convicted in 1972 and 1973 for burglary and in 1975 for first degree robbery. The prosecutor later agreed that he would not use these prior convictions during the guilt phase to impeach Dyer or any character witnesses.
At the penalty phase, Burris stipulated to these prior convictions. Based on this stipulation, and over Burris’s objection, the jury was instructed that Dyer had been convicted of two other prior convictions and of armed robbery with the use of a firearm. Burris argued that the stipulation, as far as he was concerned, was not meant to allow the prosecution a basis to argue that Dyer’s use of a firearm is evidence of violence. However, the prosecution referred to the armed robbery conviction to illustrate Dyer’s pattern of increasing violence. Dyer has now proffered evidence that indicates that he did not use a gun in the robbery and argues that Burris’s stipulation rendered his assistance constitutionally defective.
Initially, Burris believed that Dyer’s diminished capacity defense would be successful and thought that there was a good chance that Dyer would be convicted of less than first-degree murder. His focus was on keeping the convictions out the guilt phase of the trial. When he entered the stipulation, Burris did not consider the ramifications of the pretrial stipulation for the penalty phase. Burris’s initial focus on the guilt phase did not render his performance ineffective. Rather, “[t]he choice to pursue a particular strategy in one phase at the cost of lowering the likelihood of success in the other phase is a tactical decision for which there is no correct answer, but only second guesses.” Id. at 1041.
At the penalty phase, Burris’s tactic was to present Dyer as a decent person. Burris testified that he could have called the victim of the armed robbery to testify, but that doing so would have undercut his strategy. Indeed, had Burris not stipulated to the use of the firearm, the prosecution also could have called the victim of the robbery to the stand to testify. Wanting to avoid this potentially damaging testimony, Burris’s stipulation was reasonable.
IV
Dyer also contends that the jury was improperly instructed on the elements of aiding and abetting and that the erroneous instruction amounted to constitutional error. The jury was instructed that Dyer could be convicted of murder if he intentionally aided or abetted its commission or intentionally advised and encouraged its commission “with knowledge of the unlawful purpose of the person who directly and actively commit[ted] ... the crime.” This jury instruction has been held to be constitutionally deficient in People v. Beeman, 35 Cal.3d 547, 550-51, 199 Cal.Rptr. 60, 674 P.2d 1318 (1984), because the instruction did not require that Dyer act with the specific intent of aiding the principal’s crime. See California v. Roy, — U.S. -,-, 117 S.Ct. 337, 338, 136 L.Ed.2d 266 (1996) (Roy); Martinez v. Borg, 937 F.2d 422, 423 (9th Cir.1991).
In Roy, the Supreme Court held that the harmless error standard of Brecht v. Abrahamson, 507 U.S. 619, 113 S.Ct. 1710, 123 L.Ed.2d 353 (1993) (Brecht), applies to col*945lateral review of Beeman error. Roy, — U.S. at---, 117 S.Ct. at 838-39. Under this standard, we must ask “whether the error ‘had substantial and injurious effect or influence in determining the jury’s verdict.’ ” Brecht, 507 U.S. at 637, 113 S.Ct. at 1722, quoting Kotteakos v. United States, 328 U.S. 750, 776, 66 S.Ct. 1239, 1253, 90 L.Ed. 1557 (1946).
The jury convicted Dyer of four counts of kidnapping, two counts of attempted murder (Bennie Warren and Belinda Murray), and two counts of first degree murder (Nora Fluker and Floyd Murray). The jury also found that Dyer personally and intentionally inflicted great bodily injury on Fluker and Warren, but that he did not personally inflict great bodily injury on Floyd or Belinda Murray. To convict Dyer of attempted first degree murder of Belinda Murray and Warren, the jury must have found a specific intent to kill. Thus, the Beeman error did not affect these convictions.
As to Fluker, the jury found that Dyer, armed with a .45 caliber semiautomatic pistol, specifically intended to inflict great bodily injury on her and did, in fact, do so. Dyer argues that these findings do not necessarily indicate that he acted with the specific intent to kill Fluker, so that the jury may have rested its conviction on the infirm aiding and abetting instruction. Both the district court and California Supreme Court held that the jury necessarily found that Dyer “personally murdered” Fluker, so that the erroneous instruction played no role in the jury’s findings.
Although it is theoretically possible for a jury to return a special verdict of specific intent to do great bodily injury without finding a specific intent to kill, see People v. Ratliff, 41 Cal.3d 675, 695, 224 Cal.Rptr. 705, 715 P.2d 665 (1986) (fact that defendant shot victims at close range may have demonstrated intent to disable but, without more, did not establish intent to kill), absolutely no evidence in the record supports this possibility. While Fluker’s autopsy revealed that at least one of the bullets found in her body was from a .38 caliber revolver, Dyer stood over Fluker’s body with a .45 and shot her at least once. The jury specifically found that Dyer intended to kill Warren and Belinda Murray, who were lying next to Fluker. No evidence in the record could support a finding that Dyer intended to kill Warren and Belinda, but intended only to injure Fluker.
Because the jury found Dyer not guilty of inflicting great bodily harm on Floyd Murray, the jury implicitly found Dyer guilty of murdering him under the infirm aiding and abetting instruction. The prosecutor specifically asked the jury to convict Dyer of murdering Floyd Murray based on an aiding and abetting theory because the bullets removed from Floyd Murray came from a .38 caliber weapon, and there was no evidence that Dyer himself fired that gun. However, no evidence supports a finding that Dyer lacked the specific criminal intent to assist in Floyd’s murder. The California Supreme Court’s explanation of what a rational jury must have found is relevant to our inquiry:
The evidence, coupled -with the jury’s findings, showed that [Dyer] (1) intentionally assisted in kidnapping Belinda, Bennie, Nora and Floyd; (2) joined in ordering the four victims into and out of the car and onto the ground; (3) personally and intentionally inflicted great bodily injury upon Bennie and Nora; (4) attempted to murder Bennie by shooting him in the head; and (5) murdered Nora by firing [at least one] shot from a .45 caliber revolver into her body at close range. In addition, Ario had told [Dyer] at the apartment that, “if you kill one, you have to kill them all” and [Dyer] replied he would not kill the babies. We must reject [Dyer’s] theory that, under the facts of this case, a properly instructed jury could have found he intended to kill Bennie, Belinda, and Nora but not Floyd.
Dyer, 45 Cal.3d at 65, 246 Cal.Rptr. 209, 753 P.2d 1. The evidence cannot support a finding that Dyer lacked the specific intent to assist Jackson in killing Floyd Murray; thus, we hold the error harmless under Brecht.
V
Dyer next contends that he suffered prejudice from two ex parte contacts — one among certain jurors and a prosecution witness and one among certain jurors and the trial judge.
*946First, Dyer complains of contact among a prosecution witness and three jurors. Dyer has presented the testimony of Rick Bartholomew, foreperson of the jury in Dyer’s trial, who says that he and two unidentified female jurors walked by Warren as they were leaving the courthouse one day during Dyer’s trial. Bartholomew testified that Warren “said something to the effect of ‘Hang him,’ ” and that the jurors may have responded, “Don’t talk to us.” None of the jurors who encountered Warren discussed the encounter with anyone else.
We assume without deciding that this brief, unreported exchange amounted to jury misconduct. The presumed error is trial error, Thompson v. Borg, 74 F.3d 1571, 1574 (9th Cir.) (Borg), cert. denied, — U.S.-, 117 S.Ct. 227, 136 L.Ed.2d 159 (1996), and is subject to harmless-error review. Brecht, 507 U.S. at 638, 113 S.Ct. at 1722. We ask whether Warren’s statement had a substantial and injurious effect on the outcome. Borg, 74 F.3d at 1574; see also Lee v. Marshall, 42 F.3d 1296, 1298 (9th Cir.1994) (ruling that contact between jurors and police officers, where nothing substantive is said, is analyzed under Brecht for harmlessness).
Applying Brecht, it is clear that the type of error that occurred did not have a substantial and injurious effect on Dyer’s trial or sentence. One of Dyer’s victims, a key prosecution witness, told three jurors to hang Dyer. At the time of the encounter, the jurors had already heard Warren’s testimony, and it is safe to say that they were not surprised to hear that Warren, having been shot in the head by Dyer at point-blank range, would not have been too sympathetic to Dyer’s plight.
Contrary to Dyer’s suggestion, our decision is in line with Supreme Court authority. Dyer relies on Booth v. Maryland, 482 U.S. 496, 508-09, 107 S.Ct. 2529, 2535-36, 96 L.Ed.2d 440 (1987), which was explicitly overruled in Payne v. Tennessee, 501 U.S. 808, 111 S.Ct. 2597, 115 L.Ed.2d 720 (1991). Contrary to Dyer’s characterization, Payne held that “the Eighth Amendment erects no per se bar” on “the admission of victim impact evidence and prosecutorial argument.” 501 U.S. at 827, 111 S.Ct. at 2609.
Similarly, contrary to the arguments of both Dyer and the dissent, the other cases that they cite involve communications that were far more damaging and of a different nature than the one here. In Stockton v. Commonwealth of Virginia, 852 F.2d 740 (4th Cir.1988) (Stockton), cert. denied, 489 U.S. 1071, 109 S.Ct. 1354, 103 L.Ed.2d 822 (1989), Puckett, the owner of a diner, conversed with jurors who were eating lunch at his restaurant. In the course of the conversation, he told several jurors that “they ought to fry the son of a bitch.” Id. at 742. Puckett, unlike Warren, was neither a victim nor a witness. Puckett’s encounter with the jurors was far longer than the few words exchanged among Warren and the jurors. Puckett “inquired whether they had reached a decision,” id., and one juror even responded to him “that they had all decided except for ‘one damned woman.’ ” Id. In addition, Stockton was a habeas corpus case decided before Brecht. The court, applying a rule that is not the law of our circuit, see Lawson v. Borg, 60 F.3d 608, 612 (9th Cir.1995), presumed prejudice from the encounter.
Lawson involved one juror obtaining and conveying to other jurors information about the defendant’s violent reputation. In Lawson, the juror obtained “extrinsic information directly relating] to a material issue in the ease.” Id. We held that the receipt of this information had a substantial and injurious effect on the outcome. In contrast, Warren provided the jurors with his own opinion, which bore no factual relevance to the outcome. See United States v. Endicott, 869 F.2d 452, 457 (9th Cir.1989) (juror approaches main prosecution witness and says that he knows defendant is guilty; ex parte contact held not prejudicial). Likewise, Dickson v. Sullivan, 849 F.2d 403 (9th Cir. 1988), decided before Brecht, involved a highly prejudicial statement bearing on the petitioner’s recidivism. A deputy told the jury “that Dickson had done ‘something like this before.’” Id. at 408. Dickson followed a line of cases in which we have held that extrinsic evidence of prior criminal acts is highly prejudicial. Id. Warren’s emotional *947outburst can hardly be called “extrinsic evidence” of prior criminal acts.
United States v. Maree, 934 F.2d 196 (9th Cir.1991), also decided before Brecht, does not alter the outcome of this case. Maree, a direct appeal, applied a stricter standard of review. Id. at 201 (“defendant will receive a new trial only if the court finds ‘actual prejudice’ to the defendant”). Also in Maree, the juror testified that she changed her vote to guilty because two of her friends (not on the jury) told her to do so. Id. at 198-99 n. 2. Nothing in the record suggests that Warren’s statement rose to this level of prejudice.
Dyer also contends that he suffered prejudice from a contact among at least two jurors and the trial judge. These two jurors indicated that at some point, the judge saw them in a restaurant and said something to them. Both the nature of the comment and the date of the encounter are unclear.
Bartholomew testified that the judge “commended us for work well done, and he brought a fellow with us to explain that he can’t speak to us singularly or alone and that he was the 13th juror, in essence, and he had to go and review and that’s why he couldn’t really socialize.” Bartholomew also testified, “I think he made reference to he could change [the verdict] if he thought we were in error.” Another juror, Alfonsa Carney, testified that “all I recall [the trial judge] saying is that ... we were good jurors, that we listened to the evidence and that kind of thing. He said we were good jurors, we listened intensively. He said in his opinion we listened real good to the evidence. He just had a brief conversation.”
Bartholomew testified that he was “not real sure” when it took place. He testified that it may have occurred between the guilt and penalty phases, but that it also may have been “at the end of the trial.” Carney testified that “we had no contact with him when we sat as jurors,” but also that the contact may have been between the guilt and penalty phases.
Dyer argues that the trial judge’s statements diminished the jury’s sentencing responsibility and amounted to error under Caldwell v. Mississippi, 472 U.S. 320, 105 S.Ct. 2633, 86 L.Ed.2d 231 (1985). In Caldwell, the prosecutor urged the jury not to view itself as finally determining whether the defendant would die, because a death sentence would be reviewed for correctness by the state supreme court. Caldwell held, on direct appeal, that the prosecutor’s statement amounted to reversible error because “it is constitutionally impermissible to rest a death sentence on a determination made by a sentencer who has been led to believe that the responsibility for determining the appropriateness of the defendant’s death rests elsewhere.” Id. at 328-29, 105 S.Ct. at 2639.
Neither Bartholomew’s nor Carney’s testimony indicates exactly when the conversation took place. The judge’s statements that they were “good jurors” and his commendation for “work well done” suggests that the contacts occurred after the trial. Furthermore, after reading the testimony of both Bartholomew and Carney, we conclude that the trial judge did not say anything that could have prejudiced Dyer. Taking both jurors’ memories of the events together, and assuming that the contact occurred during the guilt or during the sentencing phase, it appears that the judge was simply attempting to avoid any prolonged contact without appearing rude. As the district court quoted from one of our cases, we will “not presume prejudice where a court or its staff show[s] courtesy to citizens serving as jurors.” United States v. Velasquez-Carbona, 991 F.2d 574, 576 (9th Cir.), cert. denied, 508 U.S. 979, 113 S.Ct. 2982, 125 L.Ed.2d 678 (1993); see also Rushen v. Spain, 464 U.S. 114, 118, 104 S.Ct. 453, 455-56, 78 L.Ed.2d 267 (1983) (“There is scarcely a lengthy trial in which one or more jurors do not have occasion to speak to the trial judge about something, whether it relates to a matter of personal comfort or to some aspect of the trial.”). The nature of the judge’s comments do not suggest that the jury could have been misled as to the gravity of their responsibility. See Hendricks v. Vasquez, 974 F.2d 1099, 1108 (9th Cir.1992) (Hendricks). Rather, if said before Dyer was actually sentenced, the judge’s comments merely emphasized the importance of listening closely to the evidence. The comments did not strip from the jury a *948sense of responsibility for the gravity of their task. We will not overturn Dyer’s conviction collaterally based on speculation as to the nature of the ex parte communication and the time at which it occurred. See Romano, 512 U.S. at 12-15, 114 S.Ct. at 2012-13.
The dissent cites Driscoll v. Delo, 71 F.3d 701 (8th Cir.1995) (Driscoll), cert. denied, - U.S. -, 117 S.Ct. 273, 136 L.Ed.2d 196 (1996), to show that the “thirteenth juror” communication in this case substantially and injuriously affected the jury’s deliberations under Brecht. Dissent at 965-966. Yet in Driscoll, the prosecutor told the jury several times that it simply “recommended” a death sentence, while the judge made the ultimate decision:
[Jjuries don’t sentence people to death in Missouri____ The Judge has a vote. It’s really thirteen votes. But the Judge’s vote is a veto vote. It doesn’t matter whether you return a recommendation for the death penalty.
Driscoll, 71 F.3d at 711-12 n. 8. While the judge in this case communicated that he was the “thirteenth juror,” he did so to explain why he could not socialize with the jurors. This “thirteenth juror” statement differs greatly from that in Driscoll, where the prosecutor called the judge a “thirteenth juror” only to make it easier for the jury to sentence Driscoll to death. The communication in the restaurant in no way “told the jury that it could defer the extremely difficult decision of whether or not [Dyer] should be sentenced to death.” Id. at 713.
In any event, we hold that any prejudice that could have occurred as a result of the judge’s statement was avoided by the trial court’s instruction at the penalty phase. The judge specifically instructed the jury to base its sentence only on the evidence presented and that it was to disregard anything he had done or said that may have influenced its decision in any way. See Campbell v. Kincheloe, 829 F.2d 1453, 1461 (9th Cir.1987) (no prejudice where curative instruction given), cert. denied, 488 U.S. 948, 109 S.Ct. 380, 102 L.Ed.2d 369 (1988); United States v. Madrid, 842 F.2d 1090, 1095 (9th Cir.) (error harmless where, among other instructions, judge instructed jury to base decision only on evidence in the case), cert. denied, 488 U.S. 912, 109 S.Ct. 269, 102 L.Ed.2d 256 (1988). Therefore, the judge’s contact with several jurors did not have a substantial and injurious effect on the outcome.
VI
Dyer also argues that numerous errors at the sentencing phase tainted his death sentence. He contends that the penalty-phase instructions impermissibly influenced and limited the evidence that the jury could consider in mitigation. He also insists that the instructions impermissibly permitted the jury to consider nonstatutory aggravating factors. Finally, Dyer argues that the district court improperly excluded evidence of the sentences of his codefendants.
A.
Dyer presents four challenges to his penalty-phase instructions, contending that they were misleading and that there was a reasonable likelihood that the instructions prevented the jury from considering relevant mitigating evidence.
The trial court listed the statutory mitigating circumstances and instructed the jury to consider the listed factors, if applicable. First, Dyer argues that these instructions unconstitutionally enabled the jury to transform lack of mitigation into aggravation weighing in favor of death. As Dyer acknowledges, an identical argument was recently rejected in Williams v. Calderon, 52 F.3d 1465, 1482 (9th Cir.1995) (Williams), cert. denied, — U.S.-, 116 S.Ct. 937, 133 L.Ed.2d 863 (1996), and Bonin, 59 F.3d at 848. In Bonin, we rejected Bonin’s claim that the jury’s penalty-phase instructions “allowed the juries to consider the absence of numerous possible mitigating circumstances to be aggravating circumstances.” 59 F.3d at 848. We held that “[t]he cautionary words ‘if applicable’ [which were in both Dyer’s and Bonin’s instructions] warned the jury that not all of the factors would be relevant and that the absence of a factor made it inapplicable rather than an aggravating factor.” Id. Dyer’s claim is therefore meritless.
*949Second, Dyer argues that one of the statutory mitigating factors, which allowed the jury to consider “whether or not” Dyer was “under the influence of extreme mental or emotional disturbance,” may have prevented the jury from considering Dyer’s emotional condition as mitigating evidence, if that disturbance was less than “extreme.” The same argument was rejected in Blystone v. Pennsylvania, 494 U.S. 299, 308, 110 S.Ct. 1078, 1084, 108 L.Ed.2d 255 (1990), and Hendricks, 974 F.2d at 1109. In Blystone, petitioner argued that an instruction that permitted the jury to consider “ ‘extreme’ mental or emotional disturbance” impermissibly precluded the jury’s consideration of less degrees of disturbance, impairment, or duress. 494 U.S. at 308, 110 S.Ct. at 1084. The Court rejected the claim because the jury was not prevented from considering relevant mitigating evidence. Blystone cannot be distinguished here.
Third, Dyer argues that the “catch-all” factor, permitting the jury to consider “any other circumstance which extenuates the gravity of the crime,” impermissibly limited the jury’s consideration of mitigating evidence to matters having to do with the crime itself. He argues that the jury may not have considered any mitigating evidence about his background, psychological make up, and work history. Again, the Supreme Court has rejected an identical argument. Boyde v. California, 494 U.S. 370, 381, 110 S.Ct. 1190, 1198, 108 L.Ed.2d 316 (1990) (analyzing identical CALJIC instruction, holding there was no “reasonable likelihood that ... jurors interpreted the trial court’s instructions to prevent consideration of mitigating evidence of background and character”).
Fourth, Dyer argues that another statutory factor, “whether or not at the time of the offense the capacity of the defendant to appreciate the criminality of his conduct, or to conform his conduct to the requirements of law, was impaired as a result of mental disease or defect, or the effects of intoxication,” may have prevented the jury from considering evidence of intoxication because the jury had found that the evidence was not sufficient to prove diminished capacity. Dyer contends that the jury may have been confused because of some similarity between the guilt-phase and penalty-phase instructions. However, the guilt phase required “substantial impairment,” while the penalty phase required mere “impairment.” Dyer cannot show that there was a reasonable likelihood that the jury applied the instruction in a manner that precluded consideration of relevant mitigating evidence. Id. at 380, 110 S.Ct. at 1197-98. It is particularly strained to assert that because the jurors rejected a diminished capacity defense, they believed they could not consider any evidence of intoxication in mitigation.
B.
Dyer also argues that the instruction defining “aggravating circumstance” allowed the jury to consider nonstatutoiy aggravating factors. We are bound by the California Supreme Court’s determination that there had been no violation of state law. Dyer, 45 Cal.3d at 77-78, 246 Cal.Rptr. 209, 753 P.2d 1; see Williams, 52 F.3d at 1480-81; Estelle v. McGuire, 502 U.S. 62, 67-68, 112 S.Ct. 475, 479-80, 116 L.Ed.2d 385 (1991) (“it is not the province of a federal habeas court to reexamine state-court determinations on state-law questions”). Because the error Dyer alleges involves no independent violation of his constitutional rights, see Barclay v. Florida, 463 U.S. 939, 956, 103 S.Ct. 3418, 3428, 77 L.Ed.2d 1134 (1983) (nothing in Constitution prohibits consideration of non-statutory aggravating factor); Harris v. Pulley, 692 F.2d 1189, 1193-94 (9th Cir.1982) (Harris) (rejecting argument that California death penalty statute is unconstitutional because it places no limit on introduction of aggravating factors), rev’d on other grounds, 465 U.S. 37, 104 S.Ct. 871, 79 L.Ed.2d 29 (1984), his argument fails. We also reject as meritless Dyer’s claim that California’s statute is unconstitutional because it does not require written findings as to the aggravating and mitigating factors on which the jury relied. Harris, 692 F.2d at 1195-96 (rejecting identical claim).
C.
Dyer contends that at sentencing he was entitled to have the jury hear that his *950codefendants were sentenced to life in prison. The Supreme Court has acknowledged that such evidence can be mitigating. Parker v. Dugger, 498 U.S. 308, 815, 111 S.Ct. 731, 736, 112 L.Ed.2d 812 (1991). However, it does not follow that such evidence is relevant mitigating evidence in all cases. Nor does it follow that Dyer had a constitutional right to have the jury hear such evidence. Rather, a state court is free to exclude as irrelevant “evidence not bearing on the defendant’s character, prior record, or the circumstances of his offense.” Lockett v. Ohio, 438 U.S. 586, 604 n. 12, 98 S.Ct. 2954, 2965 n. 12, 57 L.Ed.2d 973 (1978) (plurality). Evidence of Dyer’s codefendants’ sentences does not relate to his personal background or to the circumstances of the murders. The trial court held that evidence of Dyer’s eodefendants’ sentences was irrelevant, and we will not overturn this evidentiary ruling. The “Eighth Amendment does not establish a federal code of evidence to supersede state evidentiary rules in capital sentencing proceedings.” Romano, 512 U.S. at 11, 114 S.Ct. at 2011.
VII
Dyer next argues that he suffered prejudice from two of the district court’s evidentiary rulings. We review the district court’s evidentiary rulings for an abuse of discretion, and we will not reverse unless they prejudiced Dyer. See Bonin, 59 F.3d at 838.
A.
Approximately one year before the district court conducted its evidentiary hearing, Dyer deposed juror Freeland for an entire day. Although the district court decided that it would hear Freeland’s testimony at the evidentiary hearing, Dyer was unable to serve her with a subpoena. The district court ultimately reviewed Freeland’s deposition and denied Dyer’s habeas petition without hearing Freeland testify. Dyer contends that because the district court did not view Freeland’s demeanor, its decision regarding Freeland’s credibility was unreliable as the decision was not based on a complete record. Dyer does not contend that Freeland would have presented any evidence in addition to what she presented in her deposition. He merely alleges that his rights were infringed because the district court did not actually observe Freeland.
We analyze the district court’s discretionary decision to deny a continuance by weighing various factors on a case-by-case basis. United States v. Mejia, 69 F.3d 309, 314-15 & 314 n. 5 (9th Cir.1995) (Mejia). Although we have used two somewhat different sets of factors in different contexts, id. at 314 n. 5, the outcome in this case would be the same under either set. We consider:
(1) the extent of [petitioner’s] diligence in his efforts to ready his defense prior to the date set for hearing; (2) how likely it is that the need for a continuance could have been met if the continuance had been granted; (3) the extent to which granting the continuance would have inconvenienced the court and the opposing party, including witnesses; (4) the extent to which the appellant might have suffered harm as a result of the district court’s denial.
Id. at 314 (ellipses omitted), quoting United States v. Flynt, 756 F.2d 1352, 1359 (9th Cir.) (Flynt), amended, 764 F.2d 675 (9th Cir. 1985). The weight accorded to each factor may vary from case to case; but, “in order to obtain a reversal, appellant must show at a minimum that he has suffered prejudice as a result of the denial of his request.” Flynt, 756 F.2d at 1359.
We initially discuss the fih-st two factors. Dyer made numerous attempts to serve Freeland with a subpoena. Freeland was at home or in her neighborhood during the time Dyer attempted to serve her, yet Dyer was unsuccessful on 21 occasions. The attorney general gave Freeland’s telephone number and address to Dyer. After Dyer informed the district court that he was having difficulty actually serving Freeland, the court issued a memorandum advising Dyer’s counsel to “continue their efforts to serve Ms. Freeland with a subpoena if they desire to present her testimony live, in lieu of by deposition.” By the third and final day of the evidentiary hearing, Dyer still had not served Freeland.
Dyer’s inability to locate Freeland, combined with his inability to tell the district *951court when he would be able to find her, rendered the district court’s decision reasonable. Cf. Mejia, 69 F.Sd at 314, 318-19 (holding refusal to continue evidentiary hearing was abuse of discretion where, among other things, absent government witnesses were on vacation and would be available to testify in two business days). Thus, although Dyer made numerous unsuccessful attempts to serve Freeland, he could not establish that a continuance would have served any purpose. The first factor weighs in Dyer’s favor, but the second factor weighs heavily against him.
In addition, the third factor weighs against Dyer. The district court would have been inconvenienced by the indefinite continuance necessary to allow Dyer to locate Freeland. Moreover, there is evidence that Dyer’s counsel had been harassing Freeland.
Finally, the fourth factor weighs against Dyer because he has not demonstrated that the district court’s refusal to continue the hearing prejudiced him. This case is wholly unlike Mejia because the district court here, unlike in Mejia, relied, in addition to the substance of Freeland’s deposition, on the state court’s own assessment of Freeland’s credibility.
It was therefore within the discretion of the district court to refuse to continue an evidentiary hearing.
B.
The district court issued an order in which it clarified the evidence on which it relied in denying Dyer’s petition. Dyer challenges the district court’s decision to exclude as irrelevant six declarations pertaining to his behavior in prison pending trial and to the degree of his remorse. The court did not abuse its discretion in holding that these declarations were irrelevant.
Dyer’s ineffectiveness of counsel claims do not allege ineffectiveness for failing to investigate or present evidence of his behavior in jail or the degree of his remorse. Thus, the declarations were properly excluded as irrelevant.
VIII
Finally, Dyer argues that even if the alleged errors did not individually have a substantial and injurious effect on the outcome of his trial or sentence, the cumulative effect of the errors did amount to constitutional error. Although errors did occur in Dyer’s trial, neither all of them individually, nor all of them together, had a substantial and injurious effect on the outcome at either the guilt or penalty phase. Dyer is asking us “to add a group of negative numbers together and find that the sum is positive,” Fairchild v. Lockhart, 979 F.2d 636, 639 (8th Cir.1992), cert. denied, 509 U.S. 928, 113 S.Ct. 3051, 125 L.Ed.2d 735 (1993), and we will not do so.
AFFIRMED.
. Dyer argues that we should follow several of our sister circuits and interpret the concurring opinions in McDonough to hold that a juror's dishonesty is not a necessary predicate to obtaining a new trial. See McDonough, 464 U.S. at 556-57, 104 S.Ct. at 850-51 (Blackmun, J., joined by Stevens and O'Connor, JJ., concurring) ("regardless of whether a juror’s answer is honest or dishonest, it remains within a trial court’s option ... to order a post-trial hearing at which the movant has the opportunity to demonstrate ... bias”); id. at 558, 104 S.Ct. at 851 (Brennan, J., joined by Marshall, J., concurring in the judgment) ("Whether the juror answered a particular question on voir dire honestly or dishonestly, or whether an inaccurate answer was inadvertent or intentional, are simply factors to be considered in [the] determination of actual bias.”); see also Zerka v. Green, 49 F.3d 1181, 1186 n. 7 (6th Cir.1995) (counting votes in McDonough and concluding that a finding of dishonesty is not a prerequisite to relief); Amirault v. Fair, 968 F.2d 1404, 1405-06 (1st Cir.) (same), cert. denied, 506 U.S. 1000, 113 S.Ct. 602, 121 L.Ed.2d 538 (1992); Cannon v. Lockhart, 850 F.2d 437, 440 (8th Cir.1988) (same). We are bound to follow Edmond and hold that a showing of juror dishonesty is required.