Cite as: 563 U. S. ____ (2011)
Strickland v. Washington, 466 U. S. 668, provides the clearly
established federal law here. To overcome the strong presumption
that counsel has acted competently, id., at 690, a defendant must
show that counsel failed to act “reasonabl[y] considering all the cir-
cumstances,” id., at 688, and must prove the “reasonable probability
that, but for counsel’s unprofessional errors, the result of the proceed-
ing would have been different,” id., at 694. Review here is thus “dou-
bly deferential,” Knowles v. Mirzayance, 556 U. S. ___, ___, requiring
a “highly deferential” look at counsel’s performance, Strickland, su-
pra, at 689, through §2254(d)’s “deferential lens,” Mirzayance, supra,
at ___, n. 2. Pp. 16–18.
(c) Pinholster has not shown that the State Supreme Court’s de-
cision that he could not demonstrate deficient performance by his
trial counsel necessarily involved an unreasonable application of fed-
eral law. Pp. 18–26.
(1) The state-court record supports the idea that his counsel
acted strategically to get the prosecution’s aggravation witnesses ex-
cluded for lack of notice, and if that failed, to put on his mother as a
mitigation witness. Billing records show that they spent time inves-
tigating mitigating evidence. The record also shows that they had an
unsympathetic client who had boasted about his criminal history dur-
ing the guilt phase, leaving them with limited mitigation strategies.
In addition, when Dr. Stalberg concluded that Pinholster had no sig-
nificant mental disorder or defect, he was aware of Pinholster’s medi-
cal and social history. Given these impediments, it would have been
a reasonable penalty-phase strategy to focus on evoking sympathy for
Pinholster’s mother. Pinholster has responded with only a handful of
post-hoc nondenials by one of his lawyers. Pp. 18–23.
Strickland when it drew from
this Court’s recent cases a “constitutional duty to investigate” and a
principle that it was prima facie ineffective for counsel to abandon an
investigation based on rudimentary knowledge of Pinholster’s back-
ground. Beyond the general requirement of reasonableness, “specific
guidelines are not appropriate” under Strickland. 466 U. S., at 688.
Nor did the Ninth Circuit properly apply the strong presumption of
competence mandated by Strickland. Pp. 23–26.
(d) Even if his trial counsel had performed deficiently, Pinholster
also has failed to show that the State Supreme Court must have un-
reasonably concluded that he was not prejudiced. Pp. 26–31.
To determine “whether there is a reasonable probability
that, absent the errors, the sentencer . . . would have concluded that”
death was not warranted, Strickland, supra, at 695, the aggravating
evidence is reweighed “against the totality of available mitigating
evidence,” Wiggins v. Smith, 539 U. S. 510, 534. Here, the State pre-