“In deciding whether to grant an evidentiary hearing, a federal court must consider whether such a hearing could enable an applicant to prove the petition’s factual allegations, which, if true, would entitle the applicant to federal habeas relief. Because the deferential standards prescribed by §2254 control whether to grant habeas relief, a federal court must take into account those standards in deciding whether an evidentiary hearing is appropriate.” 550 U. S., at 474 (citation omitted):chanrobles.com-red

By instructing district courts to consider the §2254(d) standards in deciding whether to grant a hearing, we must have understood that the evidence admitted at a hearing could be considered in the §2254(d)(1) analysis. See Brief for American Civil Liberties Union as Amicus Curiae 9 (“The whole point of Landrigan’s admonition that the court must decide whether to hold a hearing with an eye on §2254(d)(1) is that some proffers of evidence will not justify federal fact-finding in view of §2254(d)(1), but that other proffers of proof will”).[Footnote 11]

In Michael Williams, the warden argued that §2254(e)(2) bars an evidentiary hearing whenever a petitioner was unable to develop the factual record in state court, “whether or not through his own fault or neglect.” 529 U. S., at 430. Under the warden’s argument, a petitioner who did not develop the record in state court, whatever the reason, would be barred from presenting evidence to the federal court. In rejecting that argument, we observed:clubjurisvirtuallawlibrary

“A prisoner who developed his claim in state court and can prove the state court’s decision was ‘contrary to, or involved an unreasonable application of, clearly established Federal law, as determined by the Supreme Court of the United States,’ is not barred from obtaining relief by §2254(d)(1). If the opening clause of §2254(e)(2) covers a request for an evidentiary hearing on a claim which was pursued with diligence but remained undeveloped in state court because, for instance, the prosecution concealed the facts, a prisoner lacking clear and convincing evidence of innocence could be barred from a hearing on the claim even if he could satisfy §2254(d).” Id., at 434 (citation omitted; emphasis added):chanrobles.com-red

A petitioner in the latter situation would almost certainly be unable to “satisfy §2254(d)” without introducing the concealed facts in federal court. This passage thus reflects our understanding that, in some circumstances, a petitioner might need an evidentiary hearing in federal court to prove the facts necessary to satisfy §2254(d). To avoid foreclosing habeas relief for such petitioners, we concluded that §2254(e)(2) could not bear the warden’s “harsh reading,” which essentially would have held petitioners strictly at fault for their inability to develop the facts in state court. Ibid. The majority today gives an equally “harsh reading” to §2254(d)(1) to achieve the result we rejected in Michael Williams.[Footnote 12]

None of the other cases cited by the majority supports its result. In Williams v. Taylor, 529 U. S. 362 (2000) (Terry Williams), we interpreted §2254(d)(1) to ask whether the state-court decision “identifies the correct governing legal principle from this Court’s decisions but unreasonably applies that principle to the facts of the prisoner’s case.” Id., at 413. However, we had no reason to decide whether the §2254(d)(1) inquiry was limited to the state-court record, as the District Court did not hold an evidentiary hearing in that case. See id., at 372:chanrobles.com-red

In Holland v. Jackson, we stated that “we have made clear that whether a state court’s decision was unreasonable must be assessed in light of the record the court had before it.” 542 U. S., at 652. In the next sentence, however, we observed that the evidence at issue “could have been the subject of an evidentiary hearing by the District Court, but only if respondent was not at fault in failing to develop that evidence in state court.” Id., at 652–653. We proceeded to find that the evidence was not properly admitted under §2254(e)(2) before concluding that the Court of Appeals had erred in its §2254(d)(1) analysis. Id., at 653; see also Bradshaw v. Richey, 546 U. S. 74, 79 (2005) (per curiam):chanrobles.com-red

In sum, our cases reflect our recognition that it is sometimes appropriate to consider new evidence in deciding whether a petitioner can satisfy §2254(d)(1). In reading our precedent to require the opposite conclusion, the majority disregards the concerns that motivated our decision in Michael Williams: Some petitioners, even if diligent, may be unable to develop the factual record in state court through no fault of their own. We should not interpret §2254(d)(1) to foreclose these diligent petitioners from accessing the Great Writ when the state court will not consider the new evidence and could not reasonably have reached the same conclusion with the new evidence before it:chanrobles.com-red

II

I also disagree with the Court’s conclusion that the Court of Appeals erred in holding that Pinholster had satisfied §2254(d)(1) on the basis of the state-court record.[Footnote 13]

A

The majority omits critical details relating to the performance of Pinholster’s trial counsel, the mitigating evidence they failed to discover, and the history of these proceedings. I therefore highlight several aspects of the facts and history of this case:chanrobles.com-red

1

After the jury returned a guilty verdict, the court instructed the jury to return six days later for the penalty phase. This prompted discussion at sidebar regarding whether the State had provided notice of its intent to offer aggravating evidence. Pinholster’s court-appointed attorney, Wilbur Dettmar, argued that the State should be precluded from offering aggravating evidence:clubjurisvirtuallawlibrary

“I am not presently prepared to offer anything by way of mitigation. If I was going to proceed on mitigation, the people would have the right to rebuttal with or without notice:chanrobles.com-red

“I took the position, since the people had not given notice, I had not prepared any evidence by way of mitigation. I would submit it on that basis.” 52 Reporter’s Tr. 7250 (hereinafter Tr.) (emphasis added):chanrobles.com-red

Undoubtedly anticipating that counsel might need additional time to prepare an adequate mitigation defense, the court asked Dettmar whether a continuance would be helpful in the event it ruled against him. He declined the offer on the spot, stating: “I think we would probably still go forward on Monday. Clearly the one person that comes to mind is the defendant’s mother. How much beyond that I don’t know. I don’t think the pa[ss]age of time would make a great deal of difference.” Id., at 7257–7258. After hearing testimony, the court denied Pinholster’s motion to preclude aggravating evidence:chanrobles.com-red

At the penalty phase, defense counsel called only one witness: Pinholster’s mother, Burnice Brashear. Brashear testified that Pinholster “never really wanted for anything at home too much” and “had everything normally materialwise that most people have.” Id., at 7395. She said that Pinholster was “different” from his siblings, whom she characterized as “basically very good children.” Id., at 7401–7402. Pinholster, she said, had a “friendly” relationship with his stepfather, although his stepfather “sometimes would lose his temper” with Pinholster, who “had a mind of his own.” Id., at 7392–7393; see also id., at 7293 (stating that his stepfather was “at times” “abusive or near abusive”):chanrobles.com-red

Brashear provided brief testimony regarding Pinholster’s childhood. She described two car accidents—one when she ran over him in the driveway and one when he went through the windshield. Id., at 7389–7391. She stated that he started failing school in the first grade and that the school eventually “sent him to [an] educationally handicapped class.” Id., at 7393–7394. When Pinholster was 10, a psychologist recommended placing him in a mental institution, but she “didn’t think he was that far gone.” Id., at 7395. A few years later, she testified, he spent six months in a state hospital for emotionally handicapped children. Id., at 7402:chanrobles.com-red

According to Brashear, Pinholster had suffered from epilepsy since age 18, when he was beaten in jail. Id., at 7397. She said that her family doctor, Dr. Dubin, had given him medication to treat the epilepsy. Ibid. Brashear also suggested that Pinholster did not have long to live, stating that he had “a chip in his head floating around” and that “they don’t think—he won’t be here very much longer anyway.”[Footnote 14] Ibid:chanrobles.com-red

In closing argument, the prosecutor ridiculed Brashear’s testimony. See 53 id., at 7442 (“She said his stepfather disciplined him. So what? I am sure you have all disciplined your children. I was disciplined myself”); ibid. (“He was run over by a car when he was three years old. That’s very unfortunate. There is no evidence of any brain damage. A lot of children get dropped, fall from their cribs or whatever”); id., at 7444–7445 (“I submit to you that if this defendant truly had epilepsy, … a doctor would have been brought in to tell you that. Medical records, something”). The prosecutor also highlighted Brashear’s testimony about Pinholster’s stable home environment, arguing, “He came from a good home. You heard that he was not a deprived child. Had many things going for him, probably more than many children.” Id., at 7442:chanrobles.com-red

Notwithstanding the meager mitigation case presented by Pinholster’s counsel, it took the jury two days to reach a decision to sentence Pinholster to death. His counsel later moved to modify the sentence to life imprisonment. In denying the motion, the trial judge stated, “The evidence which the defense offered concerning the defendant’s extenuation was merely some testimony from his mother that was not persuasive. His mother did not, in the court’s opinion, present any evidence which the court would find to be a moral justification or extenuation for his conduct. No witness supplied such evidence.” 54 id., at 7514:chanrobles.com-red

2

After his conviction and sentence were affirmed on appeal, Pinholster filed a habeas petition in the California Supreme Court alleging, among other things, that his counsel had “unreasonably failed to investigate, prepare and present available mitigating evidence during penalty phase.” Record ER–103:chanrobles.com-red

Pinholster’s state-court petition included 121 exhibits. In a series of declarations, his trial attorney Harry Brainard (who had by then been disbarred) confirmed what Dettmar had forthrightly told the trial court: Brainard and Dettmar neither expected nor prepared to present mitigation evidence.[Footnote 15] See id., at ER–333 (“Mr. Dettmar and I did not prepare a case in mitigation. We felt there would be no penalty phase hearing inasmuch as we did not receive written notice of evidence in aggravation pursuant to Penal Code §190.3”). Brainard further confirmed what was apparent from the mitigation case they eventually put on: They conducted virtually no mitigation investigation. See id., at ER–182 (“I have no recollection of Mr. Dettmar having secured or reviewed any of Scott’s medical records, nor did I see any of Scott’s medical records. So far as I recollect, neither Mr. Dettmar nor myself interviewed any of Scott’s previous medical providers”); id., at ER–183 (“I do not recall interviewing or attempting to interview Scott’s family members or any other persons regarding penalty phase testimony, except Mrs. Brashears [sic]”); ibid. (“I have no recollection of seeing or attempting to secure Scott’s school records, juvenile records, medical records, or records of prior placements”); ibid. (“I have no recollection of interviewing or attempting to interview Scott’s former school teachers, counselors, or juvenile officers”).[Footnote 16]

Statements by relatives (none of whom trial counsel had attempted to interview regarding Pinholster’s background) and documentary evidence revealed that the picture of Pinholster’s family life painted by his mother at trial was false. Pinholster was “raised in chaos and poverty.” Id., at ER–312. A relative remembered seeing the children mix together flour and water in an attempt to get something to eat. Pinholster’s stepfather beat him several times a week, including at least once with a two-by-four board. “There was so much violence in [the] home” that Pinholster’s brother “dreaded coming home each day.” Id., at ER–313. Pinholster’s half sister was removed from the home as a result of a beating by his stepfather:chanrobles.com-red

Documentary evidence showed, directly contrary to Brashear’s trial testimony, that Pinholster’s siblings had very troubled pasts. Pinholster’s elder brother was arrested for armed burglary, robbery, and forcible rape of a 14-year-old with a deadly weapon. While in custody, he was diagnosed as “catatonic-like” and “acutely psychotic, probably suffering some type of schizophrenia.” Id., at ER–219, ER–224. He later committed suicide.[Footnote 17] Pinholster’s half sister, a recovering alcoholic, had been made a ward of the juvenile court for prostitution and forcible sexual battery on a 14-year-old:chanrobles.com-red

Pinholster’s petition and exhibits described a long history of emotional disturbance and neurological problems. A former schoolteacher stated that, as a child, Pinholster “seemed incapable of relating either to his peers or to adults,” that “[i]t was even hard to maintain eye contact with him,” and that “[h]is hyperactivity was so extreme that [she] formed the opinion it probably had an organic base.” Id., at ER–231. School records revealed that he “talk[ed] to self continuously,” had “many grimaces,” fought in his sleep, and could “control self for only 1 hour per day.” Id., at ER–230, ER–233. He “show[ed] progressive deterioration each semester since Kindergarten.” Id., at ER–230. School officials recommended placement in a school for emotionally handicapped students and referral to a neurologist. At age nine, he had an abnormal EEG, revealing “an organic basis for his behavior.” Id., at ER–157, ER–234. Just months before the homicides, a doctor recommended placement in the Hope Psychiatric Institute, but this did not occur:chanrobles.com-red

This and other evidence attached to the petition was summarized in a declaration by Dr. George Woods. Dr. Woods opined that Pinholster “suffer[ed] from severe and long standing seizure disorders,” id., at ER–156, that his childhood head traumas “may have been the precipitating factors for [his] seizure disorder,” id., at ER–157, and that he suffered from bipolar mood disorder. He pointed to trial testimony that immediately before the burglary on the night of the homicides, Pinholster announced that he “ ‘ha[d] a message from God’ ”—which Dr. Woods believed to reflect “[a]uditory hallucinations” and “severe psychosis.” Id., at ER–169. He concluded that at the time of the homicides Pinholster “was suffering from bipolar mood disorder with psychotic ideation and was suffering a complex partial seizure.” Id., at ER–170. He also observed that Pinholster’s “grossly dysfunctional family, the abuse he received as a child, his history of suffering from substantial seizure and mood disorders, his frequently untreated psychiatric and psychological disabilities and his educational handicaps were relevant circumstances which would extenuate the gravity of the crime.” Id., at ER–171:chanrobles.com-red

On the basis of Pinholster’s submission, the California Supreme Court denied Pinholster’s ineffective-assistance-of-counsel claim:chanrobles.com-red

Pinholster then filed a habeas petition in Federal District Court. He included an additional exhibit: a declaration by Dr. John Stalberg, a psychiatrist who had hastily examined Pinholster and produced a two-page report in the middle of the original trial.[Footnote 18] After reviewing the new material collected by Pinholster’s habeas counsel, Dr. Stalberg stated that the available evidence showed a familial history of “severe psychiatric disorders,” “a history of seizure disorders of unknown etiology,” “repeated head traumas,” “an abnormal EEG,” and “evidence of mental disturbance during Mr. Pinholster’s childhood and some degree of brain damage.” Id., at ER–493. He also opined that “there [was] voluminous mitigating evidence which includes a childhood of physical abuse, emotional neglect, and a family history of mental illness and criminal behavior.” Id., at ER–494:chanrobles.com-red

The District Court stayed the federal proceedings while Pinholster sought state-court review of claims the District Court deemed unexhausted. Pinholster’s second habeas submission to the California Supreme Court included Stalberg’s declaration. That court summarily denied Pinholster’s petition on the merits:chanrobles.com-red

Pinholster returned to Federal District Court and filed an amended petition. After an evidentiary hearing, the District Court concluded that Pinholster had demonstrated deficient performance and prejudice under Strickland.[Footnote 19] The Ninth Circuit, sitting en banc, affirmed. 590 F. 3d 651:chanrobles.com-red

B

As the majority notes, Pinholster’s claim arises under Strickland v. Washington. “The benchmark for judging any claim of ineffectiveness [under Strickland] must be whether counsel’s conduct so undermined the proper functioning of the adversarial process that the trial cannot be relied on as having produced a just result.” 466 U. S., at 686. To satisfy this benchmark, a defendant must show both that “counsel’s performance was deficient” and that “the deficient performance prejudiced the defense.” Id., at 687:chanrobles.com-red

When §2254(d)(1) applies, the question is whether “ ‘fairminded jurists could disagree’ on the correctness of the state court’s decision.” Harrington, 562 U. S., at ___ (slip op., at 11) (quoting Yarborough v. Alvarado, 541 U. S. 652, 664 (2004)). When the state court rejected a Strickland claim on the pleadings assuming the allegations to be true, as here, see ante, at 16, n. 12, the federal court must ask whether “there is any reasonable argument” supporting the state court’s conclusion that the petitioner’s allegations did not state a claim, Harrington, 562 U. S., at ___ (slip op., at 16). This standard is “difficult,” but not impossible, “to meet.” Id., at ___ (slip op., at 12). This case is one in which fairminded jurists could not disagree that the state court erred:chanrobles.com-red

C

Under Strickland, “the defendant must show that counsel’s representation fell below an objective standard of reasonableness,” measured according to “prevailing professional norms.” 466 U. S., at 688. We “indulge a strong presumption that counsel’s conduct falls within the wide range of reasonable professional assistance.” Id., at 689. When §2254(d) applies, federal-court review is “ ‘doubly’ ” deferential. Harrington, 562 U. S., at ___ (slip op., at 16) (quoting Knowles v. Mirzayance, 556 U. S. ___, ___ (2009) (slip op., at 11)). In the present AEDPA posture, “[t]he question is whether there is any reasonable argument that counsel satisfied Strickland’s deferential standard.” Harrington, 562 U. S., at ___ (slip op., at 16). Here, there is none:chanrobles.com-red

The majority surmises that counsel decided on a strategy “to get the prosecution’s aggravation witnesses excluded for lack of notice, and if that failed, to put on Pinholster’s mother.” Ante, at 19. This is the sort of “ ‘post hoc rationalization’ for counsel’s decisionmaking that contradicts the available evidence of counsel’s actions” that courts cannot indulge. Harrington, 562 U. S., at ___ (slip op., at 20) (quoting Wiggins v. Smith, 539 U. S. 510 , 526–527 (2003)). The majority’s explanation for counsel’s conduct contradicts the best available evidence of counsel’s actions: Dettmar’s frank, contemporaneous statement to the trial judge that he “had not prepared any evidence by way of mitigation.” 52 Tr. 7250. The majority’s conjecture that counsel had in fact prepared a mitigation defense, based primarily on isolated entries in counsel’s billing records, requires it to assume that Dettmar was lying to the trial judge.[Footnote 20]

In any event, even if Pinholster’s counsel had a strategic reason for their actions, that would not automatically render their actions reasonable. For example, had counsel decided their best option was to move to exclude the aggravating evidence, it would have been unreasonable to forgo a mitigation investigation on the hope that the motion would be granted. With a client’s life at stake, it would “flou[t] prudence,” Rompilla v. Beard, 545 U. S. 374 , 389 (2005), for an attorney to rely on the possibility that the court might preclude aggravating evidence pursuant to a “legal technicality” without any backup plan in place in case the court denied the motion, ante, at 19. No reasonable attorney would pursue such a risky strategy. I do not understand the majority to suggest otherwise:chanrobles.com-red

Instead, I understand the majority’s conclusion that counsel’s actions were reasonable to rest on its belief that they did have a backup plan: a family-sympathy defense. In reaching this conclusion, the majority commits the same Strickland error that we corrected, applying §2254(d)(1), in Wiggins: It holds a purportedly “tactical judgment” to be reasonable without assessing “the adequacy of the investigatio[n] supporting [that] judgmen[t],” 539 U. S., at 521. As we stated in Strickland:clubjurisvirtuallawlibrary

We have repeatedly applied this principle since Strickland. See Sears v. Upton, 561 U. S. ___, ___ (2010) (per curiam) (slip op., at 9); Porter v. McCollum, 558 U. S. ___, ___ (2009) (per curiam) (slip op., at 10); Wiggins, 539 U. S., at 527; Terry Williams, 529 U. S., at 396.[Footnote 21]

As these cases make clear, the prevailing professional norms at the time of Pinholster’s trial required his attorneys to “conduct a thorough investigation of the defendant’s background,” ibid. (citing 1 ABA Standards for Criminal Justice 4–4.1, commentary, p. 4–55 (2d ed. 1980) (hereinafter ABA Standards)), or “to make a reasonable decision that makes particular investigations unnecessary,” Strickland, 466 U. S., at 691.[Footnote 22] “In judging the defense’s investigation, as in applying Strickland generally, hindsight is discounted by pegging adequacy to ‘counsel’s perspective at the time’ investigative decisions are made, and by giving a ‘heavy measure of deference to counsel’s judgments.’ ” Rompilla, 545 U. S., at 381 (quoting Strickland, 466 U. S., at 689, 691; citation omitted). In some cases, “reasonably diligent counsel may draw a line when they have good reason to think further investigation would be a waste.” Rompilla, 545 U. S., at 383; see, e.g., Bobby v. Van Hook, 558 U. S. ___, ___ (2009) (per curiam) (slip op., at 8); Burger v. Kemp, 483 U. S. 776, 794–795 (1987). In other cases, however, Strickland requires further investigation:chanrobles.com-red

Wiggins is illustrative of the competence we have required of counsel in a capital case. There, counsel’s in-vestigation was limited to three sources: psychological testing, a presentencing report, and Department of Social Services records. 539 U. S., at 523–524. The records revealed that the petitioner’s mother was an alcoholic, that he displayed emotional difficulties in foster care, that he was frequently absent from school, and that on one occasion, his mother left him alone for days without food. Id., at 525. In these circumstances, we concluded, “any reasonably competent attorney would have realized that pursuing these leads was necessary to making an informed choice among possible defenses.” Ibid. Accordingly, we held, the state court’s assumption that counsel’s investigation was adequate was an unreasonable application of Strickland. 539 U. S., at 528.[Footnote 23]

This case is remarkably similar to Wiggins. As the majority reads the record, counsel’s mitigation investigation consisted of talking to Pinholster’s mother, consulting with Dr. Stalberg, and researching epilepsy.[Footnote 24] Ante, at 20. What little information counsel gleaned from this “rudimentary” investigation, Wiggins, 539 U. S., at 524, would have led any reasonable attorney “to investigate further,” id., at 527. Counsel learned from Pinholster’s mother that he attended a class for educationally handicapped children, that a psychologist had recommended placing him in a mental institution, and that he spent time in a state hospital for emotionally handicapped children. They knew that Pinholster had been diagnosed with epilepsy:chanrobles.com-red

“[A]ny reasonably competent attorney would have realized that pursuing” the leads suggested by this information “was necessary to making an informed choice among possible defenses.” Id., at 525; see also Penry v. Lynaugh, 492 U. S. 302, 319 (1989) (“[E]vidence about the defendant’s background and character is relevant because of the belief, long held by this society, that defendants who commit criminal acts that are attributable to a disadvantaged background, or to emotional and mental problems, may be less culpable than defendants who have no such excuse” (internal quotation marks omitted)). Yet counsel made no effort to obtain the readily available evidence suggested by the information they learned, such as Pinholster’s schooling or medical records, or to contact Pinholster’s school authorities. They did not contact Dr. Dubin or the many other health-care providers who had treated Pinholster. Put simply, counsel “failed to act while potentially powerful mitigating evidence stared them in the face.” Bobby, 558 U. S., at ___ (slip op., at 8) (citing Wiggins, 539 U. S., at 525):chanrobles.com-red

The “impediments” facing counsel, ante, at 21, did not justify their minimal investigation. It is true that Pinholster was “an unsympathetic client.” Ibid. But this fact compounds, rather than excuses, counsel’s deficiency in ignoring the glaring avenues of investigation that could explain why Pinholster was the way he was. See Sears, 561 U. S., at ___ (slip op., at 7) (“This evidence might not have made Sears any more likable to the jury, but it might well have helped the jury understand Sears, and his horrendous acts—especially in light of his purportedly stable upbringing”). Nor can Dr. Stalberg’s two-page report, which was based on a very limited record and focused primarily on Pinholster’s mental state at the time of the homicides, excuse counsel’s failure to investigate the broader range of potential mitigating circumstances:chanrobles.com-red

“The record of the actual sentencing proceedings underscores the unreasonableness of counsel’s conduct by suggesting that their failure to investigate thoroughly re-sulted from inattention, not reasoned strategic judgment.” Wiggins, 539 U. S., at 526. Dettmar told the trial judge that he was unprepared to present any mitigation evidence. The mitigation case that counsel eventually put on can be described, at best, as “halfhearted.” Ibid. Counsel made no effort to bolster Brashear’s self-interested testimony with school or medical records, as the prosecutor effectively emphasized in closing argument. And because they did not pursue obvious leads, they failed to recognize that Brashear’s testimony painting Pinholster as the bad apple in a normal, nondeprived family was false:chanrobles.com-red

In denying Pinholster’s claim, the California Supreme Court necessarily overlooked Strickland’s clearly established admonition that “strategic choices made after less than complete investigation are reasonable precisely to the extent that reasonable professional judgments support the limitations.” 466 U. S., at 690–691. As in Wiggins, in light of the information available to Pinholster’s counsel, it is plain that “reasonable professional judgments” could not have supported their woefully inadequate investigation.[Footnote 25] 466 U. S., at 691. Accordingly, the California Supreme Court could not reasonably have concluded that Pinholster had failed to allege that his counsel’s investigation was inadequate under Strickland:chanrobles.com-red

D

The majority also concludes that the California Supreme Court could reasonably have concluded that Pinholster did not state a claim of prejudice. This conclusion, in light of the overwhelming mitigating evidence that was not before the jury, is wrong. To establish prejudice, “[t]he defendant must show that there is a reasonable probability that, but for counsel’s unprofessional errors, the result of the proceeding would have been different.” Id., at 694. When a habeas petitioner challenges a death sentence, “the question is whether there is a reasonable probability that, absent the errors, the sentencer … would have concluded that the balance of aggravating and mitigating circumstances did not warrant death.” Id., at 695. This inquiry requires evaluating “the totality of the available mitigation evidence—both that adduced at trial, and the evidence adduced in the habeas proceeding—in reweighing it against the evidence in aggravation.” Terry Williams, 529 U. S., at 397–398. The ultimate question in this case is whether, taking into account all the mitigating and aggravating evidence, “there is a reasonable probability that at least one juror would have struck a different balance.” Wiggins, 539 U. S., at 537; see Cal. Penal Code Ann. §190.4(b) (West 2008) (requiring a unanimous jury verdict to impose a death sentence):chanrobles.com-red

1

Like the majority, I first consider the aggravating and mitigating evidence presented at trial. By virtue of its verdict in the guilt phase, the jury had already concluded that Pinholster had stabbed and killed the victims. As the majority states, the jury saw Pinholster “revel” in his history of burglaries during the guilt phase. Ante, at 26. The jury heard evidence of Pinholster’s violent tendencies: He had kidnapped someone with a knife, cut a person in the arm with a razor, and had a history of hitting and kicking people. He threatened to kill the State’s lead witness. And he had an extensive disciplinary record in jail:chanrobles.com-red

Brashear offered brief testimony that was apparently intended to be mitigating. See supra, at 19–20; see also ante, at 27–28.[Footnote 26] However, as the prosecutor argued, Brashear was not a neutral witness. See 53 Tr. 7441 (“A mother clearly loves her son, ladies and gentlemen. Clearly not the most unbiased witness in the world”). Notwithstanding Brashear’s obvious self-interest, counsel failed to offer readily available, objective evidence that would have substantiated and expanded on her testimony. Their failure to do so allowed the prosecutor to belittle her testimony in closing argument. See supra, at 19–20. And Brashear’s statement that Pinholster would not be alive much longer because he had “a chip in his head floating around,” 52 Tr. 7397, could only have undermined her credibility, as the prosecutor urged, see 53 id., at 7447 (“Does she want you to believe sometime before he got to country jail some doctor looked in a crystal ball and said, ‘In three years you are going to die’? That’s ridiculous”). The trial judge was thoroughly unimpressed with Brashear’s testimony. See supra, at 20:chanrobles.com-red

Moreover, the evidence presented in Pinholster’s state-court petition revealed that Brashear distorted facts in her testimony in ways that undermined Pinholster’s mitigation case. As in Sears, 561 U. S., at ___ (slip op., at 3), the prosecutor used Brashear’s testimony that Pinholster came from a good family against him. See 53 Tr. 7442:chanrobles.com-red

In sum, counsel presented little in the way of mitigating evidence, and the prosecutor effectively used their halfhearted attempt to present a mitigation case to advocate for the death penalty. The jury nonetheless took two days to reach a decision to impose a death sentence:chanrobles.com-red

2

The additional mitigating evidence presented to the California Supreme Court “adds up to a mitigation case that bears no relation” to Brashear’s unsubstantiated testimony. Rompilla, 545 U. S., at 393:chanrobles.com-red

Assuming the evidence presented to the California Supreme Court to be true, as that court was required to do, the new mitigating evidence presented to that court would have shown that Pinholster was raised in “chaos and poverty.” Record ER–312. The family home was filled with violence. Pinholster’s siblings had extremely troubled pasts. There was substantial evidence of “mental disturbance during Mr. Pinholster’s childhood and some degree of brain damage.” Id., at ER–493:chanrobles.com-red

Dr. Woods concluded that Pinholster’s aggressive conduct resulted from bipolar mood disorder. Just months before the murders, a doctor had recommended that Pinholster be sent to a psychiatric institute. Dr. Woods also explained that Pinholster’s bizarre behavior before the murders reflected “[a]uditory hallucinations” and “severe psychosis.” Id., at ER–169. The available records confirmed that Pinholster suffered from longstanding seizure disorders, which may have been caused by his childhood head injuries:chanrobles.com-red

On this record, I do not see how it can be said that “[t]he ‘new’ evidence largely duplicated the mitigation evidence at trial.” Ante, at 29; see Arizona v. Fulminante, 499 U. S. 279, 298–299 (1991) (evidence is not “merely cumulative” if it corroborates other evidence that is “unbelievable” on its own). Brashear’s self-interested testimony was not confirmed with objective evidence, as the prosecutor highlighted. The new evidence would have “destroyed the [relatively] benign conception of [Pinholster’s] upbringing” presented by his mother. Rompilla, 545 U. S., at 391. The jury heard no testimony at all that Pinholster likely suffered from brain damage or bipolar mood disorder, and counsel offered no evidence to help the jury understand the likely effect of Pinholster’s head injuries or his bizarre behavior on the night of the homicides. The jury heard no testimony recounting the substantial evidence of Pinholster’s likely neurological problems. And it heard no medical evidence that Pinholster suffered from epilepsy:chanrobles.com-red

The majority responds that “much” of Pinholster’s new mitigating evidence “is of questionable mitigating value.” Ante, at 29. By presenting psychiatric testimony, it contends, “Pinholster would have opened the door to rebuttal by a state expert.” Ibid. But, because the California Supreme Court denied Pinholster’s petition on the pleadings, it had no reason to know what a state expert might have said. Moreover, given the record evidence, it is reasonably probable that at least one juror would have credited his expert. In any event, even if a rebuttal expert testified that Pinholster suffered from antisocial personality disorder, this would hardly have come as a surprise to the jury. See ante, at 22 (describing Pinholster as a “psychotic client whose performance at trial hardly endeared him to the jury”). It is for this reason that it was especially important for counsel to present the available evidence to help the jury understand Pinholster. See Sears, 561 U. S., at ___ (slip op., at 6–7):chanrobles.com-red

Had counsel conducted an adequate investigation, the judge and jury would have heard credible evidence showing that Pinholster’s criminal acts and aggressive tendencies were “attributable to a disadvantaged background, or to emotional and mental problems.” Penry, 492 U. S., at 319 (internal quotation marks omitted). They would have learned that Pinholster had the “ ‘kind of troubled history we have declared relevant to assessing a defendant’s moral culpability.’ ” Porter, 558 U. S., at ___ (slip op., at 12) (quoting Wiggins, 539 U. S., at 535). Applying Strickland, we have repeatedly found “a reasonable probability,” 466 U. S., at 694, that the sentencer would have reached a different result had counsel presented similar evidence. See, e.g., Porter, 558 U. S., at ___ (slip op., at 12–13) (evidence of the defendant’s childhood history of physical abuse, brain abnormality, limited schooling, and heroic military service); Rompilla, 545 U. S., at 392 (evidence of severe abuse and neglect as a child, as well as brain damage); Wiggins, 539 U. S., at 535 (evidence of the defendant’s “severe privation and abuse” as a child, homelessness, and “diminished mental capacities”); Terry Williams, 529 U. S., at 398 (evidence of childhood mistreatment and neglect, head injuries, possible organic mental impairments, and borderline mental retardation):chanrobles.com-red

The majority does not dispute the similarity between this case and the cited cases. However, it criticizes the Court of Appeals for relying on Rompilla and Terry Williams on the ground that we reviewed the prejudice question de novo in those cases. See ante, at 31. I do not read Terry Williams to review the prejudice question de novo.[Footnote 27] More fundamentally, however, I cannot agree with the premise that “[t]hose cases … offer no guidance with respect to whether a state court has unreasonably determined that prejudice is lacking.” Ante, at 31 (emphasis deleted). In each of these cases, we did not purport to create new law; we simply applied the same clearly established precedent, Strickland, to a different set of facts. Because these cases illuminate the kinds of mitigation evidence that suffice to establish prejudice under Strickland, they provide useful, but not dispositive, guidance for courts to consider when determining whether a state court has unreasonably applied Strickland:chanrobles.com-red

In many cases, a state court presented with additional mitigation evidence will reasonably conclude that there is 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. This is not such a case. Admittedly, Pinholster unjustifiably stabbed and killed two people, and his history of violent outbursts and burglaries surely did not endear him to the jury. But the homicides did not appear premeditated. And the State’s aggravation case was no stronger than in Rompilla and Terry Williams. See 545 U. S., at 378, 383 (the defendant committed murder by torture and had a significant history of violent felonies, including a rape); 529 U. S., at 418 (Rehnquist, C.J., concurring in part and dissenting in part) (the defendant had a lifetime of crime, and after the murder he “savagely beat an elderly woman,” set a home on fire, and stabbed a man (internal quotation marks omitted)). Even on the trial record, it took the jury two days to decide on a penalty. The contrast between the “not persuasive” mitigation case put on by Pinholster’s counsel, 54 Tr. 7514, and the substantial mitigation evidence at their fingertips was stark. Given these considerations, it is not a foregone conclusion, as the majority deems it, that a juror familiar with his troubled background and psychiatric issues would have reached the same conclusion regarding Pinholster’s culpability. Fairminded jurists could not doubt that, on the record before the California Supreme Court, “there [was] a reasonable probability that at least one juror would have struck a different balance.” Wiggins, 539 U. S., at 537:chanrobles.com-red

III

The state-court record on its own was more than adequate to support the Court of Appeals’ conclusion that the California Supreme Court could not reasonably have rejected Pinholster’s Strickland claim. The additional evidence presented in the federal evidentiary hearing only confirms that conclusion:chanrobles.com-red

A

At the hearing, Pinholster offered many of the same documents that were before the state habeas court. He also offered his trial attorneys’ billing records, which were before the state habeas court as part of the trial record. Of the seven lay witnesses who testified at the hearing, six had previously executed declarations in support of Pinholster’s state-court petition. (The seventh, Pinholster’s uncle, provided testimony cumulative of other testimony.)

Two experts testified on Pinholster’s behalf; neither had presented declarations to the state habeas court. The first was Dr. Donald Olson, assistant professor of neurology and neurological sciences and director of the Pediatric Epilepsy Program at Stanford University Medical Center. It appears that Pinholster retained Dr. Olson to rebut the testimony of the expert disclosed by the State in the federal proceeding. See Decl. of Michael D. Abzug in Support of Stipulated Ex Parte Application to Continue Evidentiary Hearing and Discovery Cut-Off and to Substitute Counsel in Pinholster v. Calderon, No. CV 95–6240–GLT (CD Cal.), p. 2. Relying in part on Pinholster’s abnormal EEG, Dr. Olson opined that Pinholster’s childhood accidents “likely result[ed] in brain injury” and that these injuries “conferred a risk of epilepsy.” Record ER–699 to ER–700. He concluded that it was reasonably probable that Pinholster had suffered from partial epilepsy since at least 1968 and had suffered from brain injury since at least 1964. Id., at ER–701:chanrobles.com-red

Pinholster’s second expert was Dr. Sophia Vinogradov, associate professor of psychiatry at the University of California, San Francisco. Dr. Vinogradov’s testimony was based on essentially the same facts as Dr. Woods’ and Dr. Stalberg’s state-court declarations. She highlighted Pinholster’s childhood head traumas, history of epilepsy, abusive and neglected upbringing, history of substance abuse, and bizarre behavior on the night of the homicides. She opined that his aggressive behavior resulted from childhood head traumas:clubjurisvirtuallawlibrary

“All data indicates that there were severe effects of the two serious head injuries sustained at age 2 and age 3, with evidence for behavioral changes related to dysfunction of frontal cortex: severe attentional and learning problems in childhood, hyperactivity, aggressivity, impulsivity, social-emotional impairment, seizure disorder, and explosive dyscontrol.” Id., at ER–731:chanrobles.com-red

She also opined that, right before the homicides, Pinholster was in an “apparently hallucinatory state [that] was likely the result of his intoxication with multiple substances.” Id., at ER–707

The State presented two experts: Dr. Stalberg, the psychiatrist who had examined Pinholster in the middle of trial,[Footnote 28] and Dr. David Rudnick. Although Dr. Stalberg maintained that Pinholster suffered from antisocial personality disorder, which was his original diagnosis in the middle of trial, he again emphasized that there was “voluminous” and “compelling” mitigation evidence that had not previously been made available to him or presented to the jury. Id., at ER–926, ER–953. He stated that conversations with Pinholster’s family revealed that he and his siblings were “raised like animals, wild animals,” id., at ER–948, and he opined that Pinholster’s upbringing was a risk factor for antisocial personality disorder. See ibid. (Pinholster’s upbringing “would speak volumes, looking at it from a mitigation point of view”). And he agreed that the mitigation evidence presented at trial was “profoundly misleading.” Id., at ER–966. Dr. Rudnick testified that Pinholster suffered from antisocial personality disorder:chanrobles.com-red

The State also introduced into evidence the 1978 probation report that Pinholster’s counsel had in their possession at the time of his trial. The report demonstrated that counsel were aware that Pinholster was in classes for educationally handicapped children, that he was committed to a state hospital for emotionally handicapped children, and that he suffered two “severe head injuries.” Id., at SER–243:chanrobles.com-red

B

Much of the evidence presented at the federal hearing was duplicative of the evidence submitted to the California Supreme Court. The additional evidence presented at the hearing only confirmed that the California Supreme Court could not reasonably have rejected Pinholster’s claim.[Footnote 29]

For example, the probation report presented by the State confirmed that counsel had in their possession information that would have led any reasonable attorney “to investigate further.” Wiggins, 539 U. S., at 527. Counsel nevertheless took no action to investigate these leads:chanrobles.com-red

Pinholster’s experts opined that his childhood head traumas likely resulted in brain injury and conferred a risk of epilepsy. Although the State presented testimony that Pinholster had antisocial personality disorder, it was not clear error for the District Court to conclude that jurors could have credited Pinholster’s experts. Even the State’s own expert, Dr. Stalberg, testified to the “voluminous” mitigation evidence in Pinholster’s case. Record ER–926:chanrobles.com-red

In sum, the evidence confirmed what was already apparent from the state-court record: Pinholster’s counsel failed to conduct an adequate mitigation investigation, and there was a reasonable probability that at least one juror confronted with the “voluminous” mitigating evidence counsel should have discovered would have voted to spare Pinholster’s life. Ibid. Accordingly, whether on the basis of the state- or federal-court record, the courts below correctly concluded that Pinholster had shown that the California Supreme Court’s decision reflected an unreasonable application of Strickland.[Footnote 30]

*  *  *

I cannot agree with either aspect of the Court’s ruling. I fear the consequences of the Court’s novel interpretation of §2254(d)(1) for diligent state habeas petitioners with compelling evidence supporting their claims who were unable, through no fault of their own, to present that evidence to the state court that adjudicated their claims. And the Court’s conclusion that the California Supreme Court reasonably denied Pinholster’s ineffective-assistance-of-counsel claim overlooks counsel’s failure to investigate obvious avenues of mitigation and the contrast between the woefully inadequate mitigation case they presented and the evidence they should and would have discovered. I respectfully dissent.

Footnote 1

Relatedly, a state prisoner must, as a general matter, properly exhaust his federal claims in state court to avoid having his claim defaulted on procedural grounds. See Coleman v. Thompson, 501 U. S. 722, 750 (1991).

Footnote 2

Section 2254(e)(2) also governs an attempt to obtain relief “based on new evidence without an evidentiary hearing.” Holland v. Jackson, 542 U. S. 649 , 653 (2004) (per curiam) (emphasis deleted).

Footnote 3

See, e.g., nn. 5, 7, and 13, infra.

Footnote 4

See, e.g., Michael Williams, 529 U. S. 420 , 432 (2000) (noting that diligent efforts to develop the facts might be “thwarted, for example, by the conduct of another or by happenstance”); id., at 434 (noting that the prosecution might have “concealed the facts” supporting “a claim which was pursued with diligence”); Townsend v. Sain, 372 U. S. 293, 313 (1963) (requiring federal courts to grant evidentiary hearings when, inter alia, “the fact-finding procedure employed by the state court was not adequate to afford a full and fair hearing” or “there is a substantial allegation of newly discovered evidence”), overruled in part on other grounds by Keeney v. Tamayo-Reyes, 504 U. S. 1 , 5 (1992).

Footnote 5

Of course, §2254(d)(1) only applies when a state court has adjudicated a claim on the merits. There may be situations in which new evidence supporting a claim adjudicated on the merits gives rise to an altogether different claim. See, e.g., Reply Brief for Petitioner 10–11 (evidence withheld by the prosecutor relating to one claim may give rise to a separate claim under Brady v. Maryland, 373 U. S. 83 (1963)). The majority opinion does not foreclose this possibility:chanrobles.com-red

I assume that the majority does not intend to suggest that review is limited to the state-court record when a petitioner’s inability to develop the facts supporting his claim was the fault of the state court itself. See generally Tr. of Oral Arg. in Bell v. Kelly, O. T. 2008, No. 07–1223.

Footnote 6

See, e.g., id., at 37–38 (statement by counsel for the respondent warden that Virginia law bars all successive habeas applications, even in cases where the petitioner has new evidence).

Footnote 7

The majority declines, however, to provide any guidance to the lower courts on how to distinguish claims adjudicated on the merits from new claims.

Footnote 8

Even if it can fairly be argued that my hypothetical petitioner has a new claim, the majority fails to explain how a diligent petitioner with new evidence supporting an existing claim can present his new evidence to a federal court.

Footnote 9

In this vein, it is the majority’s approach that “would not take seriously AEDPA’s requirement that federal courts defer to state-court decisions.” Ante, at 10, n. 3.

Footnote 10

Under my reading of §2254(d)(1), of course, the district court would review properly admitted new evidence through the deferential lens of §2254(d)(1), not de novo.

Footnote 11

The majority overlooks this aspect of Landrigan. It quotes Landrigan’s observation that “if the record refutes the applicant’s factual allegations or otherwise precludes habeas relief, a district court is not required to hold an evidentiary hearing,” 550 U. S., at 474, but that statement has no bearing on the question decided by the Court today.

Footnote 12

The majority claims that Michael Williams supports its reading of §2254(d)(1). With respect to one claim asserted by the petitioner, we observed that “[t]he Court of Appeals rejected this claim on the merits under §2254(d)(1), so it is unnecessary to reach the question whether §2254(e)(2) would permit a hearing on the claim.” 529 U. S., at 444. That statement merely reflects the fact that the Court of Appeals had rejected that claim under §2254(d)(1) without considering whether the petitioner was entitled to a hearing because the petitioner had not requested a hearing on that claim. See Williams v. Taylor, 189 F. 3d 421, 425, 428–429 (CA4 1999).

Footnote 13

I agree with the majority that the state-court record in this case consists of “the ‘allegations of [the] habeas corpus petition … and … any matter of record pertaining to the case.’ ” Ante, at 16, n. 12 (quoting In re Hochberg, 2 Cal. 3d 870, 874, n. 2, 471 P. 2d 1, 3–4, n. 2 (1970); some internal quotation marks omitted):chanrobles.com-red

The majority does not decide which of the two state-court decisions should be reviewed. See ante, at 15, n. 11. One amicus argues that Pinholster must prove that both state-court decisions involved an unreasonable application of law. See Brief for Criminal Justice Legal Foundation as Amicus Curiae 26. This argument is based on amicus’ understanding that the California Supreme Court rejected the second petition as successive and, alternatively, on the merits. The State has not argued, however, that the second ruling rests on a procedural ground. See ante, at 6, n. 2. When a state court denies two petitions on the merits and the difference between the petitions is that the second petition contains additional evidence supporting the petitioner’s claim, I see no reason why the petitioner must independently show that the first decision was unreasonable.

Footnote 14

The judge instructed the jury to disregard this testimony upon motion by the prosecutor, but the prosecutor then discussed the testimony in her closing argument. See infra, at 33–34.

Footnote 15

By the time of Pinholster’s state-court habeas petition, Dettmar was deceased.

Footnote 16

Counsel’s billing records, which were before the California Supreme Court as part of the trial record, confirmed Brainard’s recollection.

Footnote 17

According to Pinholster’s half sister, “The death of our brother Alvin was a severe emotional blow to me and to Scott. I believed Scott’s substance abuse (heroin) arose following and as a result of Alvin’s death.” Record ER–314.

Footnote 18

Counsel had arranged for Dr. Stalberg to examine Pinholster in the middle of his original trial. The only documents they provided to him were police reports relating to the case and a 1978 probation report. In a two-page report that focused primarily on Pinholster’s mental state at the time of the offenses, Dr. Stalberg concluded that Pinholster had “psychopathic personality traits.” Id., at ER–187.

Footnote 19

The District Court based its decision on the evidence adduced at an evidentiary hearing. The District Court did not apply 28 U. S. C. §2254(d) because it thought, erroneously, that the California Supreme Court had not adjudicated Pinholster’s claim on the merits. App. to Pet. for Cert. 257. For the reasons I discuss, however, the District Court could have concluded that Pinholster had satisfied §2254(d)(1) on the basis of the state-court record alone.

Footnote 20

The majority misleadingly cites entries showing that counsel were preparing Brashear’s penalty phase testimony after counsel learned that the State intended to present aggravation evidence. The cited entries predating that event show only that counsel conducted about one day’s worth of investigation—consisting of talking to Brashear and researching epilepsy—two months before the penalty phase. See 3 Clerk’s Tr. 798 (1.5-hour phone call to Brashear on Jan. 13); id., at 864, 869 (3-hour meeting with Brashear regarding “childhood problems” on Feb. 23); id., at 869 (3.5 hours for “[r]esearch re; epilepsy and conf. with nurse” on Feb. 25). There is no evidence in the records that counsel actually planned to present mitigating evidence. Indeed, their complete failure to follow up on any of the information they learned in their minimal investigation only confirms that they were not planning to present mitigating evidence. See infra, at 29–31.

Footnote 21

I do not doubt that a decision to present a family-sympathy mitigation defense might be consistent “with the standard of professional competence in capital cases that prevailed in Los Angeles in 1984” in some cases. Ante, at 24. My point is that even if counsel made a strategic decision to proceed with such a defense, that decision was unreasonable because it was based on an unreasonably incomplete investigation.

Footnote 22

See also 1 ABA Standards 4–4.1, commentary, at 4–55 (“Information concerning the defendant’s background, education, employment record, mental and emotional stability, family relationships, and the like, will be relevant, as will mitigating circumstances surrounding the commission of the offense itself”). As we recognized in Strickland, the ABA Standards, though not dispositive, “are guides to determining what is reasonable.” 466 U. S., at 688; see also Wiggins v. Smith, 539 U. S. 510 , 524 (2003).

Footnote 23

As the majority notes, see ante, at 24–25, Wiggins’ trial counsel acknowledged that the investigation he conducted was inconsistent with standard practice in Maryland. See 539 U. S., at 524. We independently concluded, however, that the investigation “was also unreasonable in light of what counsel actually discovered in the … records.” Id., at 525 (emphasis added).

Footnote 24

The majority also posits that Brainard likely spent time preparing Pinholster’s brother Terry. However, Terry averred in a declaration that Pinholster’s attorneys “never asked [him] any questions relating to Scott’s background or [their] family history.” Record ER–313.

Footnote 25

The majority chastises the Court of Appeals for “attributing strict rules to this Court’s recent case law.” Ante, at 24. I agree that courts should not interpret our cases to prescribe strict rules regarding the required scope of mitigation investigations. See Rompilla v. Beard, 545 U. S. 374 , 394 (2005) (O’Connor, J., concurring) (noting “our longstanding case-by-case approach to determining whether an attorney’s performance was unconstitutionally deficient under Strickland”). The Ninth Circuit, however, did no such thing. It appropriately gave thoughtful consideration to the guideposts contained in these cases, just as we have previously done. See, e.g., Bobby v. Van Hook, 558 U. S. ___, ___ (2009) (per curiam) (slip op., at 8).

Footnote 26

The majority mischaracterizes several aspects of Brashear’s testimony. Although Brashear testified that the family “didn’t have lots of money,” she followed up that comment by stating that Pinholster did not bring friends to the house because “it was too nice a house.” 52 Tr. 7404. The prosecutor did not understand Brashear to have testified that Pinholster’s childhood was deprived. See 53 id., at 7442 (“You heard that he was not a deprived child”). Nor did the California Supreme Court on direct appeal. People v. Pinholster, 1 Cal. 4th 865, 910, 824 P. 2d 571, 587 (1992):chanrobles.com-red

Brashear did testify that Pinholster’s stepfather tried to “discipline” him and that he was “at times” “abusive or near abusive.” 52 Tr. 7392–7393. She suggested, however, that Pinholster deserved the “discipline” he received. See, e.g., id., at 7392 (“Scott was always—he had a mind of his own”). It is unlikely the jury understood Brashear to be suggesting that her husband routinely beat Pinholster. The prosecutor did not come away with this understanding. See 53 id., at 7442.

Footnote 27

Terry Williams held that the state court’s decision was “unreasonable in at least two respects”: (1) It applied the wrong legal standard, see 529 U. S., at 397, and (2) it “failed to accord appropriate weight to the body of mitigation evidence available to trial counsel,” id., at 398. We did not purport to conduct de novo review.

Footnote 28

Before the hearing, Dr. Stalberg had opined that Pinholster was “substantially impaired by a bipolar mood disorder operating synergistically with intoxication and a seizure disorder at the time the crime was committed.” Record ER–587. At a prehearing deposition, however, Dr. Stalberg revised his opinion and stated that he continued to believe that Pinholster suffered from psychopathic personality traits. After the deposition, Pinholster elected to proceed with a different expert, presumably in light of Dr. Stalberg’s unexpected change in position. The State then retained Dr. Stalberg as its own expert.

Footnote 29

The State argues that the District Court was not entitled to rely on the evidence adduced at the hearing because Pinholster was not diligent in developing his claims in state court and the hearing was therefore barred by 28 U. S. C. §2254(e)(2). This argument is somewhat imprecise. Pinholster’s allegations in his amended federal petition were “identical” to the allegations he presented to the California Supreme Court, ante, at 6, and he diligently requested a hearing in state court. The State presumably means to argue that Pinholster’s new expert testimony changed “the factual basis” of his claim such that, by the time of the evidentiary hearing, he no longer satisfied §2254(e)(2). However, at oral argument, the State suggested that Pinholster was presenting an altogether new claim in the federal court. See Tr. of Oral Arg. 18. If that is the case, §2254(d)(1) does not apply at all, and the State should be arguing lack of exhaustion or procedural default. I do not understand Pinholster to have presented a new claim to the District Court:chanrobles.com-red

In any event, Pinholster satisfied §2254(e)(2) in this case. He made “a reasonable attempt, in light of the information available at the time, to investigate and pursue claims in state court.” Michael Williams, 529 U. S., at 435. His experts relied on the very same facts and evidence. I cannot read §2254(e)(2) to impose a strict requirement that petitioners must use the same experts they presented to the state court. This rule would result in numerous practical problems, for example in the case of the unanticipated death of an expert.

Footnote 30

The State’s challenge in this Court is limited to the questions whether the Federal District Court was entitled to consider the additional evidence in the §2254(d)(1) analysis and whether Pinholster satisfied §2254(d)(1) on the basis of the state-court record. It has not challenged the District Court’s ultimate conclusion that Pinholster had proved that he was “in custody in violation of the Constitution or laws or treaties of the United States.” §2254(a).