(Slip Opinion)              OCTOBER TERM, 2010                                       1

                                       Syllabus

         NOTE: Where it is feasible, a syllabus (headnote) will be released, as is
       being done in connection with this case, at the time the opinion is issued.
       The syllabus constitutes no part of the opinion of the Court but has been
       prepared by the Reporter of Decisions for the convenience of the reader.
       See United States v. Detroit Timber & Lumber Co., 200 U. S. 321, 337.


SUPREME COURT OF THE UNITED STATES

                                       Syllabus

                 HARRINGTON, WARDEN v. RICHTER

CERTIORARI TO THE UNITED STATES COURT OF APPEALS FOR
                  THE NINTH CIRCUIT

   No. 09–587.      Argued October 12, 2010—Decided January 19, 2011
In 1994, deputies called to drug dealer Johnson’s California home found
  Johnson wounded and Klein fatally wounded. Johnson claimed that
  he was shot in his bedroom by respondent Richter’s codefendant,
  Branscombe; that he found Klein on the living room couch; and that
  his gun safe, a pistol, and cash were missing. His account was cor
  roborated by evidence at the scene, including, relevant here, spent
  shell casings, blood spatters, and blood pooled in the bedroom door
  way. Investigators took a blood sample from a wall near the bedroom
  door, but not from the blood pool. A search of Richter’s home turned
  up the safe and ammunition matching evidence at the scene. After
  his arrest on murder and other charges, Richter initially denied his
  involvement, but later admitted disposing of Johnson’s and
  Branscombe’s guns. The prosecution initially built its case on John
  son’s testimony and the circumstantial evidence, but it adjusted its
  approach after Richter’s counsel, in his opening statement, outlined
  the theory that Branscombe shot Johnson in self-defense and that
  Klein was killed in the crossfire in the bedroom doorway, and
  stressed the lack of forensic support for the prosecution’s case. The
  prosecution then decided to call an expert in blood pattern evidence,
  who testified that it was unlikely that Klein had been shot outside
  the living room and then moved to the couch, and a serologist, who
  testified that the blood sample taken near the blood pool could be
  Johnson’s but not Klein’s. Under cross-examination, she conceded
  that she had not tested the sample for cross-contamination and that
  a degraded sample would make it difficult to tell if it had blood of
  Klein’s type. Defense counsel called Richter to tell his conflicting
  version of events and called other witnesses to corroborate Richter’s
  version. Richter was convicted and sentenced to life without parole.
2                      HARRINGTON v. RICHTER

                                  Syllabus

    He later sought habeas relief from the California Supreme Court, as
    serting, inter alia, that his counsel provided ineffective assistance,
    see Strickland v. Washington, 466 U. S. 668, when he failed to pre
    sent expert testimony on blood evidence, because it could have dis
    closed the blood pool’s source and bolstered Richter’s theory. He also
    offered affidavits from forensics experts to support his claim. The
    court denied the petition in a one-sentence summary order. Subse
    quently, he reasserted his state claims in a federal habeas petition.
    The District Court denied his petition. A Ninth Circuit panel af
    firmed, but the en banc court reversed. Initially it questioned
    whether 28 U. S. C. §2254(d)—which, as amended by the Antiterror
    ism and Effective Death Penalty Act of 1996 (AEDPA), limits the
    availability of federal habeas relief for claims previously “adjudicated
    on the merits” in state court—applied to Richter’s petition, since the
    State Supreme Court issued only a summary denial. But it found the
    state-court decision unreasonable anyway. In its view, trial counsel
    was deficient in failing to consult blood evidence experts in planning
    a trial strategy and in preparing to rebut expert evidence the prose
    cution might—and later did—offer.
Held:
    1. Section 2254(d) applies to Richter’s petition, even though the
 state court’s order was unaccompanied by an opinion explaining the
 court’s reasoning. Pp. 7–10.
       (a) By its terms, §2254(d) bars relitigation of a claim “adjudicated
 on the merits” in state court unless, among other exceptions, the ear
 lier state-court “decision” involved “an unreasonable application” of
 “clearly established Federal law, as determined by” this Court,
 §2254(d)(1). Nothing in its text—which refers only to a “decision” re
 sulting “from an adjudication”—requires a statement of reasons.
 Where the state-court decision has no explanation, the habeas peti
 tioner must still show there was no reasonable basis for the state
 court to deny relief. There is no merit to the assertion that applying
 §2254(d) when state courts issue summary rulings will encourage
 those courts to withhold explanations. The issuance of summary dis
 positions can enable state judiciaries to concentrate resources where
 most needed. Pp. 7–9.
       (b) Nor is there merit to Richter’s argument that §2254(d) does
 not apply because the California Supreme Court did not say it was
 adjudicating his claim “on the merits.” When a state court has de
 nied relief, adjudication on the merits can be presumed absent any
 contrary indication or state-law procedural principles. The presump
 tion may be overcome by a more likely explanation for the state
 court’s decision, but Richter does not make that showing here. Pp. 9–
 10.
                   Cite as: 562 U. S. ____ (2011)                     3

                              Syllabus

   2. Richter was not entitled to the habeas relief ordered by the
Ninth Circuit. Pp. 10–24.
      (a) That court failed to accord the required deference to the deci
sion of a state court adjudicating the same claims later presented in
the federal habeas petition. Its opinion shows an improper under
standing of §2254(d)’s unreasonableness standard and operation in
the context of a Strickland claim. Asking whether the state court’s
application of Strickland’s standard was unreasonable is different
from asking whether defense counsel’s performance fell below that
standard. Under AEDPA, a state court must be granted a deference
and latitude that are not in operation in a case involving direct re
view under Strickland. A state court’s determination that a claim
lacks merit precludes federal habeas relief so long as “fair-minded ju
rists could disagree” on the correctness of that decision. Yarborough
v. Alvarado, 541 U. S. 652, 664. And the more general the rule being
considered, “the more leeway courts have in reaching outcomes in
case-by-case determinations.” Ibid. The Ninth Circuit explicitly con
ducted a de novo review and found a Strickland violation; it then de
clared without further explanation that the state court’s contrary de
cision was unreasonable. But §2254(d) requires a habeas court to
determine what arguments or theories supported, or could have sup
ported, the state-court decision; and then to ask whether it is possible
fair-minded jurists could disagree that those arguments or theories
are inconsistent with a prior decision of this Court. AEDPA’s unrea
sonableness standard is not a test of the confidence of a federal ha
beas court in the conclusion it would reach as a de novo matter. Even
a strong case for relief does not make the state court’s contrary con
clusion unreasonable. Section 2254(d) is designed to confirm that
state courts are the principal forum for asserting constitutional chal
lenges to state convictions. Pp. 10–14.
      (b) The Ninth Circuit erred in concluding that Richter demon
strated an unreasonable application of Strickland by the state court.
Pp. 14–23.
        (1) Richter could have secured relief in state court only by
showing both that his counsel provided deficient assistance and that
prejudice resulted. To be deficient, counsel’s representation must
have fallen “below an objective standard of reasonableness,” Strick
land, 466 U. S., at 688; and there is a “strong presumption” that
counsel’s representation is within the “wide range” of reasonable pro
fessional assistance, id., at 689. The question is whether counsel
made errors so fundamental that counsel was not functioning as the
counsel guaranteed by the Sixth Amendment. Prejudice requires
demonstrating “a reasonable probability that, but for counsel’s unpro
fessional errors, the result of the proceeding would have been differ
4                      HARRINGTON v. RICHTER

                                  Syllabus

    ent.” Id., at 694. “Surmounting Strickland’s high bar is never . . .
    easy.” Padilla v. Kentucky, 559 U. S.___, ___. Strickland can func
    tion as a way to escape rules of waiver and forfeiture. The question is
    whether an attorney’s representation amounted to incompetence un
    der prevailing professional norms, not whether it deviated from best
    practices or most common custom. Establishing that a state court’s
    application of Strickland was unreasonable under §2254(d) is even
    more difficult, since both standards are “highly deferential,” 466 U. S,
    at 689, and since Strickland’s general standard has a substantial
    range of reasonable applications. The question under §2254(d) is not
    whether counsel’s actions were reasonable, but whether there is any
    reasonable argument that counsel satisfied Strickland’s deferential
    standard. Pp. 14–16.
           (2) The Ninth Circuit erred in holding that because Richter’s
    attorney had not consulted forensic blood experts or introduced ex
    pert evidence, the State Supreme Court could not reasonably have
    concluded counsel provided adequate representation.
       A state court could reasonably conclude that a competent attorney
    could elect a strategy that did not require using blood evidence ex
    perts. Rare are the situations in which the latitude counsel enjoys
    will be limited to any one technique or approach. There were any
    number of experts whose insight might have been useful to the de
    fense. Counsel is entitled to balance limited resources in accord with
    effective trial tactics and strategies. In finding otherwise the Ninth
    Circuit failed to “reconstruct the circumstances of counsel’s chal
    lenged conduct” and “evaluate the conduct from counsel’s perspective
    at the time.” Strickland, supra, at 689. Given the many factual dif
    ferences between the prosecution and defense versions of events, it
    was far from evident at the time of trial that the blood source was
    central to Richter’s case. And relying on “the harsh light of hind
    sight” to cast doubt on a trial that took place over 15 years ago is pre
    cisely what Strickland and AEDPA seek to prevent. See Bell v. Cone,
    535 U. S. 685, 702. Even had the value of expert testimony been ap
    parent, it would be reasonable to conclude that a competent attorney
    might elect not to use it here, where counsel had reason to question
    the truth of his client’s account. Making blood evidence a central is
    sue could also have led the prosecution to produce its own expert
    analysis, possibly destroying Richter’s case, or distracted the jury
    with esoteric questions of forensic science. Defense counsel’s opening
    statement may have inspired the prosecution to present forensic evi
    dence, but that shows only that the defense strategy did not work out
    as well as hoped. In light of the record here there was no basis to
    rule that the state court’s determination was unreasonable.
       The Court of Appeals erred in dismissing such concern as an inac
                      Cite as: 562 U. S. ____ (2011)                        5

                                  Syllabus

  curate account of counsel’s actual thinking, since Strickland exam
  ined only the objective reasonableness of counsel’s actions. As to
  whether counsel was constitutionally deficient for not preparing ex
  pert testimony as a response to the prosecution’s, an attorney may
  not be faulted for a reasonable miscalculation or lack of foresight or
  for failing to prepare for remote possibilities. Here, even if counsel
  was mistaken, the prosecution itself did not expect to present forensic
  testimony until the eve of trial. Thus, it is at least debatable whether
  counsel’s error was so fundamental as to call the trial’s fairness into
  doubt. Even if counsel should have foreseen the prosecution’s tactic,
  Richter would still need to show it was indisputable that Strickland
  required his attorney to rely on a rebuttal witness rather than on
  cross-examination to discredit the witnesses, but Strickland imposes
  no such requirement. And while it is possible an isolated error can
  constitute ineffective assistance if it is sufficiently egregious, it is dif
  ficult to establish ineffective assistance where counsel’s overall per
  formance reflects active and capable advocacy. Pp. 16–22.
          (3) The Ninth Circuit also erred in concluding that Richter had
  established prejudice under Strickland, which asks whether it is
  “reasonably likely” the verdict would have been different, 466 U. S.,
  at 696, not whether a court can be certain counsel’s performance had
  no effect on the outcome or that reasonable doubt might have been
  established had counsel acted differently. There must be a substan
  tial likelihood of a different result. The State Supreme Court could
  have reasonably concluded that Richter’s prejudice evidence fell short
  of this standard. His expert serology evidence established only a
  theoretical possibility of Klein’s blood being in the blood pool; and at
  trial, defense counsel extracted a similar concession from the prose
  cution’s expert. It was also reasonable to find Richter had not estab
  lished prejudice given that he offered no evidence challenging other
  conclusions of the prosecution’s experts, e.g., that the blood sample
  matched Johnson’s blood type. There was, furthermore, sufficient
  conventional circumstantial evidence pointing to Richter’s guilt, in
  cluding, e.g., the items found at his home. Pp. 22–23.
578 F. 3d 944, reversed and remanded.

  KENNEDY, J., delivered the opinion of the Court, in which ROBERTS,
C. J., and SCALIA, THOMAS, BREYER, ALITO, and SOTOMAYOR, JJ., joined.
GINSBURG, J., filed an opinion concurring in the judgment. KAGAN, J.,
took no part in the consideration or decision of the case.
                       Cite as: 562 U. S. ____ (2011)                              1

                            Opinion of the Court

    NOTICE: This opinion is subject to formal revision before publication in the
    preliminary print of the United States Reports. Readers are requested to
    notify the Reporter of Decisions, Supreme Court of the United States, Wash
    ington, D. C. 20543, of any typographical or other formal errors, in order
    that corrections may be made before the preliminary print goes to press.


SUPREME COURT OF THE UNITED STATES
                                  _________________

                                  No. 09–587
                                  _________________


  KELLY HARRINGTON, WARDEN, PETITIONER v. 

             JOSHUA RICHTER 

 ON WRIT OF CERTIORARI TO THE UNITED STATES COURT OF

            APPEALS FOR THE NINTH CIRCUIT

                              [January 19, 2011] 


   JUSTICE KENNEDY delivered the opinion of the Court.
   The writ of habeas corpus stands as a safeguard against
imprisonment of those held in violation of the law. Judges
must be vigilant and independent in reviewing petitions
for the writ, a commitment that entails substantial judi
cial resources. Those resources are diminished and mis
spent, however, and confidence in the writ and the law it
vindicates undermined, if there is judicial disregard for
the sound and established principles that inform its
proper issuance. That judicial disregard is inherent in the
opinion of the Court of Appeals for the Ninth Circuit here
under review. The Court of Appeals, in disagreement with
the contrary conclusions of the Supreme Court of the State
of California and of a United States District Court, or
dered habeas corpus relief granted to set aside the convic
tion of Joshua Richter, respondent here. This was clear
error.
   Under 28 U. S. C. §2254(d), the availability of federal
habeas relief is limited with respect to claims previously
“adjudicated on the merits” in state-court proceedings.
The first inquiry this case presents is whether that pro
2                HARRINGTON v. RICHTER

                     Opinion of the Court

vision applies when state-court relief is denied without
an accompanying statement of reasons. If it does, the
question is whether the Court of Appeals adhered to the
statute’s terms, in this case as it relates to ineffective
assistance claims judged by the standard set forth in
Strickland v. Washington, 466 U. S. 668 (1984). A second
case decided today, Premo v. Moore, post, p. ___, presents
similar issues. Here, as in that case, it is necessary to
reverse the Court of Appeals for failing to accord required
deference to the decision of a state court.

                            I
  It is necessary to begin by discussing the details of a
crime committed more than a decade and a half ago.

                             A
   Sometime after midnight on December 20, 1994, sher
iff’s deputies in Sacramento County, California, arrived at
the home of a drug dealer named Joshua Johnson. Hours
before, Johnson had been smoking marijuana in the com
pany of Richter and two other men, Christian Branscombe
and Patrick Klein. When the deputies arrived, however,
they found only Johnson and Klein. Johnson was hysteri
cal and covered in blood. Klein was lying on a couch in
Johnson’s living room, unconscious and bleeding. Klein
and Johnson each had been shot twice. Johnson recov
ered; Klein died of his wounds.
   Johnson gave investigators this account: After falling
asleep, he awoke to find Richter and Branscombe in his
bedroom, at which point Branscombe shot him. Johnson
heard more gunfire in the living room and the sound of his
assailants leaving. He got up, found Klein bleeding on the
living room couch, and called 911. A gun safe, a pistol,
and $6,000 cash, all of which had been in the bedroom,
were missing.
                 Cite as: 562 U. S. ____ (2011)           3

                     Opinion of the Court

   Evidence at the scene corroborated Johnson’s account.
Investigators found spent shell casings in the bedroom
(where Johnson said he had been shot) and in the living
room (where Johnson indicated Klein had been shot). In
the living room there were two casings, a .32 caliber and a
.22 caliber. One of the bullets recovered from Klein’s body
was a .32 and the other was a .22. In the bedroom there
were two more casings, both .32 caliber. In addition detec
tives found blood spatter near the living room couch and
bloodstains in the bedroom. Pools of blood had collected in
the kitchen and the doorway to Johnson’s bedroom. Inves
tigators took only a few blood samples from the crime
scene. One was from a blood splash on the wall near
the bedroom doorway, but no sample was taken from the
doorway blood pool itself.
   Investigators searched Richter’s residence and found
Johnson’s gun safe, two boxes of .22-caliber ammunition,
and a gun magazine loaded with cartridges of the same
brand and type as the boxes. A ballistics expert later
concluded the .22-caliber bullet that struck Klein and
the .22-caliber shell found in the living room matched the
ammunition found in Richter’s home and bore markings
consistent with the model of gun for which the magazine
was designed.
   Richter and Branscombe were arrested. At first Richter
denied involvement. He would later admit taking John
son’s pistol and disposing of it and of the .32-caliber
weapon Branscombe used to shoot Johnson and Klein.
Richter’s counsel produced Johnson’s missing pistol, but
neither of the guns used to shoot Johnson and Klein was
found.
                             B
  Branscombe and Richter were tried together on charges
of murder, attempted murder, burglary, and robbery.
Only Richter’s case is presented here.
4                HARRINGTON v. RICHTER

                     Opinion of the Court

   The prosecution built its case on Johnson’s testimony
and on circumstantial evidence. Its opening statement
took note of the shell casings found at the crime scene and
the ammunition and gun safe found at Richter’s residence.
Defense counsel offered explanations for the circumstan
tial evidence and derided Johnson as a drug dealer, a
paranoid, and a trigger-happy gun fanatic who had drawn
a pistol on Branscombe and Richter the last time he had
seen them. And there were inconsistencies in Johnson’s
story. In his 911 call, for instance, Johnson first said
there were four or five men who had broken into his
house, not two; and in the call he did not identify Richter
and Branscombe among the intruders.
   Blood evidence does not appear to have been part of the
prosecution’s planned case prior to trial, and investigators
had not analyzed the few blood samples taken from the
crime scene. But the opening statement from the defense
led the prosecution to alter its approach. Richter’s attor
ney outlined the theory that Branscombe had fired on
Johnson in self-defense and that Klein had been killed not
on the living room couch but in the crossfire in the bed
room doorway. Defense counsel stressed deficiencies in
the investigation, including the absence of forensic support
for the prosecution’s version of events.
   The prosecution took steps to adjust to the counterat
tack now disclosed. Without advance notice and over the
objection of Richter’s attorney, one of the detectives who
investigated the shootings testified for the prosecution as
an expert in blood pattern evidence. He concluded it was
unlikely Klein had been shot outside the living room and
then moved to the couch, given the patterns of blood on
Klein’s face, as well as other evidence including “high
velocity” blood spatter near the couch consistent with the
location of a shooting. The prosecution also offered testi
mony from a serologist. She testified the blood sample
taken near the pool by the bedroom door could be John
                 Cite as: 562 U. S. ____ (2011)           5

                     Opinion of the Court

son’s but not Klein’s.
  Defense counsel’s cross-examination probed weaknesses
in the testimony of these two witnesses. The detective
who testified on blood patterns acknowledged that his
inferences were imprecise, that it was unlikely Klein had
been lying down on the couch when shot, and that he could
not say the blood in the living room was from either of
Klein’s wounds. Defense counsel elicited from the serolo
gist a concession that she had not tested the bedroom
blood sample for cross-contamination. She said that if the
year-old sample had degraded, it would be difficult to tell
whether blood of Klein’s type was also present in the
sample.
  For the defense, Richter’s attorney called seven wit
nesses. Prominent among these was Richter himself.
Richter testified he and Branscombe returned to Johnson’s
house just before the shootings in order to deliver some
thing to one of Johnson’s roommates. By Richter’s ac
count, Branscombe entered the house alone while Richter
waited in the driveway; but after hearing screams and
gunshots, Richter followed inside. There he saw Klein
lying not on the couch but in the bedroom doorway, with
Johnson on the bed and Branscombe standing in the
middle of the room. According to Richter, Branscombe
said he shot at Johnson and Klein after they attacked him.
Other defense witnesses provided some corroboration for
Richter’s story. His former girlfriend, for instance, said
she saw the gun safe at Richter’s house shortly before the
shootings.
  The jury returned a verdict of guilty on all charges.
Richter was sentenced to life without parole. On appeal,
his conviction was affirmed. People v. Branscombe, 72
Cal. Rptr. 2d 773 (Cal. App. 1998) (officially depublished).
The California Supreme Court denied a petition for re
view, People v. Branscombe, No. S069751, 1998 Cal.
LEXIS 4252 (June 24, 1998), and Richter did not file a
6                HARRINGTON v. RICHTER

                     Opinion of the Court

petition for certiorari with this Court.    His conviction
became final.
                              C
   Richter later petitioned the California Supreme Court
for a writ of habeas corpus. He asserted a number of
grounds for relief, including ineffective assistance of coun
sel. As relevant here, he claimed his counsel was deficient
for failing to present expert testimony on serology, pathol
ogy, and blood spatter patterns, testimony that, he argued,
would disclose the source of the blood pool in the bedroom
doorway. This, he contended, would bolster his theory
that Johnson had moved Klein to the couch.
   He offered affidavits from three types of forensic ex
perts. First, he provided statements from two blood se
rologists who said there was a possibility Klein’s blood was
intermixed with blood of Johnson’s type in the sample
taken from near the pool in the bedroom doorway. Second,
he provided a statement from a pathologist who said the
blood pool was too large to have come from Johnson given
the nature of his wounds and his own account of his ac
tions while waiting for the police. Third, he provided a
statement from an expert in bloodstain analysis who said
the absence of “a large number of satellite droplets” in
photographs of the area around the blood in the bedroom
doorway was inconsistent with the blood pool coming from
Johnson as he stood in the doorway. App. 118. Richter
argued this evidence established the possibility that the
blood in the bedroom doorway came from Klein, not John
son. If that were true, he argued, it would confirm his
account, not Johnson’s. The California Supreme Court
denied Richter’s petition in a one-sentence summary
order. See In re Richter, No. S082167 (Mar. 28, 2001),
App. to Pet. for Cert. 22a. Richter did not seek certiorari
from this Court.
   After the California Supreme Court issued its summary
                 Cite as: 562 U. S. ____ (2011)            7

                     Opinion of the Court

order denying relief, Richter filed a petition for habeas
corpus in United States District Court for the Eastern
District of California. He reasserted the claims in his
state petition. The District Court denied his petition, and
a three-judge panel of the Court of Appeals for the Ninth
Circuit affirmed. See Richter v. Hickman, 521 F. 3d 1222
(2008). The Court of Appeals granted rehearing en banc
and reversed the District Court’s decision. See Richter v.
Hickman, 578 F. 3d 944 (2009).
   As a preliminary matter, the Court of Appeals ques
tioned whether 28 U. S. C. §2254(d) was applicable to
Richter’s petition, since the California Supreme Court
issued only a summary denial when it rejected his Strick
land claims; but it determined the California decision was
unreasonable in any event and that Richter was entitled
to relief. The court held Richter’s trial counsel was defi
cient for failing to consult experts on blood evidence in
determining and pursuing a trial strategy and in prepar
ing to rebut expert evidence the prosecution might—and
later did—offer. Four judges dissented from the en banc
decision.
   We granted certiorari. 559 U. S. ___ (2010).
                              II
  The statutory authority of federal courts to issue habeas
corpus relief for persons in state custody is provided by 28
U. S. C. §2254, as amended by the Antiterrorism and
Effective Death Penalty Act of 1996 (AEDPA). The text of
§2254(d) states:
      “An application for a writ of habeas corpus on behalf
    of a person in custody pursuant to the judgment of a
    State court shall not be granted with respect to any
    claim that was adjudicated on the merits in State
    court proceedings unless the adjudication of the
    claim—
      “(1) resulted in a decision that was contrary to, or
8                HARRINGTON v. RICHTER

                     Opinion of the Court

    involved an unreasonable application of, clearly estab
    lished Federal law, as determined by the Supreme
    Court of the United States; or
       “(2) resulted in a decision that was based on an un
    reasonable determination of the facts in light of the
    evidence presented in the State court proceeding.”
As an initial matter, it is necessary to decide whether
§2254(d) applies when a state court’s order is unaccompa
nied by an opinion explaining the reasons relief has been
denied.
  By its terms §2254(d) bars relitigation of any claim
“adjudicated on the merits” in state court, subject only to
the exceptions in §§2254(d)(1) and (d)(2). There is no text
in the statute requiring a statement of reasons. The
statute refers only to a “decision,” which resulted from an
“adjudication.” As every Court of Appeals to consider the
issue has recognized, determining whether a state court’s
decision resulted from an unreasonable legal or factual
conclusion does not require that there be an opinion from
the state court explaining the state court’s reasoning. See
Chadwick v. Janecka, 312 F. 3d 597, 605–606 (CA3 2002);
Wright v. Secretary for Dept. of Corrections, 278 F. 3d
1245, 1253–1254 (CA11 2002); Sellan v. Kuhlman, 261
F. 3d 303, 311–312 (CA2 2001); Bell v. Jarvis, 236 F. 3d
149, 158–162 (CA4 2000) (en banc); Harris v. Stovall, 212
F. 3d 940, 943, n. 1 (CA6 2000); Aycox v. Lytle, 196 F. 3d
1174, 1177–1178 (CA10 1999); James v. Bowersox, 187
F. 3d 866, 869 (CA8 1999). And as this Court has ob
served, a state court need not cite or even be aware of our
cases under §2254(d). Early v. Packer, 537 U. S. 3, 8
(2002) (per curiam). Where a state court’s decision is
unaccompanied by an explanation, the habeas petitioner’s
burden still must be met by showing there was no reason
able basis for the state court to deny relief. This is so
whether or not the state court reveals which of the ele
                 Cite as: 562 U. S. ____ (2011)            9

                     Opinion of the Court

ments in a multipart claim it found insufficient, for
§2254(d) applies when a “claim,” not a component of one,
has been adjudicated.
   There is no merit to the assertion that compliance with
§2254(d) should be excused when state courts issue sum
mary rulings because applying §2254(d) in those cases will
encourage state courts to withhold explanations for their
decisions. Opinion-writing practices in state courts are
influenced by considerations other than avoiding scrutiny
by collateral attack in federal court. Cf. In re Robbins, 18
Cal. 4th 770, 778, n. 1, 959 P. 2d 311, 316, n. 1 (1998)
(state procedures limiting habeas are “a means of protect
ing the integrity of our own appeal and habeas corpus
process,” rather than a device for “insulating our judg
ments from federal court review” (emphasis deleted)). At
the same time, requiring a statement of reasons could
undercut state practices designed to preserve the integrity
of the case-law tradition. The issuance of summary dispo
sitions in many collateral attack cases can enable a state
judiciary to concentrate its resources on the cases where
opinions are most needed. See Brief for California Attor
neys for Criminal Justice et al. as Amici Curiae 8 (noting
that the California Supreme Court disposes of close to
10,000 cases a year, including more than 3,400 original
habeas corpus petitions).
   There is no merit either in Richter’s argument that
§2254(d) is inapplicable because the California Supreme
Court did not say it was adjudicating his claim “on the
merits.” The state court did not say it was denying the
claim for any other reason. When a federal claim has been
presented to a state court and the state court has denied
relief, it may be presumed that the state court adjudicated
the claim on the merits in the absence of any indication or
state-law procedural principles to the contrary. Cf. Harris
v. Reed, 489 U. S. 255, 265 (1989) (presumption of a merits
determination when it is unclear whether a decision ap
10                HARRINGTON v. RICHTER

                     Opinion of the Court

pearing to rest on federal grounds was decided on another
basis).
   The presumption may be overcome when there is reason
to think some other explanation for the state court’s deci
sion is more likely. See, e.g., Ylst v. Nunnemaker, 501
U. S. 797, 803 (1991). Richter, however, does not make
that showing. He mentions the theoretical possibility that
the members of the California Supreme Court may not
have agreed on the reasons for denying his petition. It is
pure speculation, however, to suppose that happened in
this case. And Richter’s assertion that the mere possibil
ity of a lack of agreement prevents any attribution of
reasons to the state court’s decision is foreclosed by prece
dent. See ibid.
   As has been noted before, the California courts or Legis
lature can alter the State’s practices or elaborate more
fully on their import. See Evans v. Chavis, 546 U. S. 189,
197, 199 (2006). But that has not occurred here. This
Court now holds and reconfirms that §2254(d) does not
require a state court to give reasons before its decision can
be deemed to have been “adjudicated on the merits.”
Richter has failed to show that the California Supreme
Court’s decision did not involve a determination of the
merits of his claim. Section 2254(d) applies to his petition.
                             III
  Federal habeas relief may not be granted for claims
subject to §2254(d) unless it is shown that the earlier state
court’s decision “was contrary to” federal law then clearly
established in the holdings of this Court, §2254(d)(1);
Williams v. Taylor, 529 U. S. 362, 412 (2000); or that
it “involved an unreasonable application of” such law,
§2254(d)(1); or that it “was based on an unreasonable
determination of the facts” in light of the record before the
state court, §2254(d)(2).
  The Court of Appeals relied on the second of these ex
                 Cite as: 562 U. S. ____ (2011)          11

                     Opinion of the Court

ceptions to §2254(d)’s relitigation bar, the exception in
§2254(d)(1) permitting relitigation where the earlier state
decision resulted from an “unreasonable application of”
clearly established federal law. In the view of the Court of
Appeals, the California Supreme Court’s decision on Rich
ter’s ineffective-assistance claim unreasonably applied the
holding in Strickland. The Court of Appeals’ lengthy
opinion, however, discloses an improper understanding of
§2254(d)’s unreasonableness standard and of its operation
in the context of a Strickland claim.
  The pivotal question is whether the state court’s appli
cation of the Strickland standard was unreasonable. This
is different from asking whether defense counsel’s per
formance fell below Strickland’s standard. Were that the
inquiry, the analysis would be no different than if, for
example, this Court were adjudicating a Strickland claim
on direct review of a criminal conviction in a United States
district court. Under AEDPA, though, it is a necessary
premise that the two questions are different. For purposes
of §2254(d)(1), “an unreasonable application of federal law
is different from an incorrect application of federal law.”
Williams, supra, at 410. A state court must be granted a
deference and latitude that are not in operation when the
case involves review under the Strickland standard itself.
  A state court’s determination that a claim lacks merit
precludes federal habeas relief so long as “fairminded
jurists could disagree” on the correctness of the state
court’s decision. Yarborough v. Alvarado, 541 U. S. 652,
664 (2004).        And as this Court has explained,
“[E]valuating whether a rule application was unreason
able requires considering the rule’s specificity. The more
general the rule, the more leeway courts have in reaching
outcomes in case-by-case determinations.” Ibid. “[I]t is
not an unreasonable application of clearly established
Federal law for a state court to decline to apply a specific
legal rule that has not been squarely established by this
12               HARRINGTON v. RICHTER

                     Opinion of the Court

Court.” Knowles v. Mirzayance, 556 U. S. ___, ___ (2009)
(slip op., at 9–10) (internal quotation marks omitted).
   Here it is not apparent how the Court of Appeals’ analy
sis would have been any different without AEDPA. The
court explicitly conducted a de novo review, 578 F. 3d, at
952; and after finding a Strickland violation, it declared,
without further explanation, that the “state court’s deci
sion to the contrary constituted an unreasonable applica
tion of Strickland.” 578 F. 3d, at 969. AEDPA demands
more. Under §2254(d), a habeas court must determine
what arguments or theories supported or, as here, could
have supported, the state court’s decision; and then it
must ask whether it is possible fairminded jurists could
disagree that those arguments or theories are inconsistent
with the holding in a prior decision of this Court. The
opinion of the Court of Appeals all but ignored “the only
question that matters under §2254(d)(1).” Lockyer v.
Andrade, 538 U. S. 63, 71 (2003).
   The Court of Appeals appears to have treated the un
reasonableness question as a test of its confidence in the
result it would reach under de novo review: Because the
Court of Appeals had little doubt that Richter’s Strickland
claim had merit, the Court of Appeals concluded the state
court must have been unreasonable in rejecting it. This
analysis overlooks arguments that would otherwise justify
the state court’s result and ignores further limitations of
§2254(d), including its requirement that the state court’s
decision be evaluated according to the precedents of this
Court. See Renico v. Lett, 559 U. S. ___, ___ (2010) (slip
op., at 11–12). It bears repeating that even a strong case
for relief does not mean the state court’s contrary conclu
sion was unreasonable. See Lockyer, supra, at 75.
   If this standard is difficult to meet, that is because it
was meant to be. As amended by AEDPA, §2254(d) stops
short of imposing a complete bar on federal court relitiga
tion of claims already rejected in state proceedings. Cf.
                 Cite as: 562 U. S. ____ (2011)           13

                     Opinion of the Court

Felker v. Turpin, 518 U. S. 651, 664 (1996) (discussing
AEDPA’s “modified res judicata rule” under §2244). It
preserves authority to issue the writ in cases where there
is no possibility fairminded jurists could disagree that the
state court’s decision conflicts with this Court’s prece
dents. It goes no farther. Section 2254(d) reflects the view
that habeas corpus is a “guard against extreme malfunc
tions in the state criminal justice systems,” not a substi
tute for ordinary error correction through appeal. Jackson
v. Virginia, 443 U. S. 307, 332, n. 5 (1979) (Stevens, J.,
concurring in judgment). As a condition for obtaining
habeas corpus from a federal court, a state prisoner must
show that the state court’s ruling on the claim being pre
sented in federal court was so lacking in justification that
there was an error well understood and comprehended in
existing law beyond any possibility for fairminded dis
agreement.
   The reasons for this approach are familiar. “Federal
habeas review of state convictions frustrates both the
States’ sovereign power to punish offenders and their
good-faith attempts to honor constitutional rights.”
Calderon v. Thompson, 523 U. S. 538, 555–556 (1998)
(internal quotation marks omitted). It “disturbs the
State’s significant interest in repose for concluded litiga
tion, denies society the right to punish some admitted
offenders, and intrudes on state sovereignty to a degree
matched by few exercises of federal judicial authority.”
Reed, 489 U. S., at 282 (KENNEDY, J., dissenting).
   Section 2254(d) is part of the basic structure of federal
habeas jurisdiction, designed to confirm that state courts
are the principal forum for asserting constitutional chal
lenges to state convictions. Under the exhaustion re
quirement, a habeas petitioner challenging a state convic
tion must first attempt to present his claim in state court.
28 U. S. C. §2254(b). If the state court rejects the claim on
procedural grounds, the claim is barred in federal court
14               HARRINGTON v. RICHTER

                     Opinion of the Court

unless one of the exceptions to the doctrine of Wainwright
v. Sykes, 433 U. S. 72, 82–84 (1977), applies. And if the
state court denies the claim on the merits, the claim is
barred in federal court unless one of the exceptions to
§2254(d) set out in §§2254(d)(1) and (2) applies. Section
2254(d) thus complements the exhaustion requirement
and the doctrine of procedural bar to ensure that state
proceedings are the central process, not just a preliminary
step for a later federal habeas proceeding, see id., at 90.
   Here, however, the Court of Appeals gave §2254(d) no
operation or function in its reasoning. Its analysis illus
trates a lack of deference to the state court’s determina
tion and an improper intervention in state criminal proc
esses, contrary to the purpose and mandate of AEDPA and
to the now well-settled meaning and function of habeas
corpus in the federal system.
                             IV
  The conclusion of the Court of Appeals that Richter
demonstrated an unreasonable application by the state
court of the Strickland standard now must be discussed.
To have been entitled to relief from the California Su
preme Court, Richter had to show both that his counsel
provided deficient assistance and that there was prejudice
as a result.
  To establish deficient performance, a person challenging
a conviction must show that “counsel’s representation fell
below an objective standard of reasonableness.” 466 U. S.,
at 688. A court considering a claim of ineffective assis
tance must apply a “strong presumption” that counsel’s
representation was within the “wide range” of reasonable
professional assistance. Id., at 689. The challenger’s
burden is to show “that counsel made errors so serious
that counsel was not functioning as the ‘counsel’ guaran
teed the defendant by the Sixth Amendment.” Id., at 687.
  With respect to prejudice, a challenger must demon
                  Cite as: 562 U. S. ____ (2011)           15

                      Opinion of the Court

strate “a reasonable probability that, but for counsel’s
unprofessional errors, the result of the proceeding would
have been different. A reasonable probability is a prob
ability sufficient to undermine confidence in the outcome.”
Id., at 694. It is not enough “to show that the errors had
some conceivable effect on the outcome of the proceeding.”
Id., at 693. Counsel’s errors must be “so serious as to
deprive the defendant of a fair trial, a trial whose result is
reliable.” Id., at 687.
   “Surmounting Strickland’s high bar is never an easy
task.” Padilla v. Kentucky, 559 U. S. ___, ___ (2010) (slip
op., at 14). An ineffective-assistance claim can function as
a way to escape rules of waiver and forfeiture and raise
issues not presented at trial, and so the Strickland stan
dard must be applied with scrupulous care, lest “intrusive
post-trial inquiry” threaten the integrity of the very ad
versary process the right to counsel is meant to serve.
Strickland, 466 U. S., at 689–690. Even under de novo
review, the standard for judging counsel’s representation
is a most deferential one. Unlike a later reviewing court,
the attorney observed the relevant proceedings, knew of
materials outside the record, and interacted with the
client, with opposing counsel, and with the judge. It is “all
too tempting” to “second-guess counsel’s assistance after
conviction or adverse sentence.” Id., at 689; see also Bell
v. Cone, 535 U. S. 685, 702 (2002); Lockhart v. Fretwell,
506 U. S. 364, 372 (1993). The question is whether an
attorney’s representation amounted to incompetence
under “prevailing professional norms,” not whether it
deviated from best practices or most common custom.
Strickland, 466 U. S., at 690.
   Establishing that a state court’s application of Strick
land was unreasonable under §2254(d) is all the more
difficult.   The standards created by Strickland and
§2254(d) are both “highly deferential,” id., at 689; Lindh v.
Murphy, 521 U. S. 320, 333, n. 7 (1997), and when the two
16                HARRINGTON v. RICHTER

                     Opinion of the Court

apply in tandem, review is “doubly” so, Knowles, 556 U. S.,
at ___ (slip op., at 11). The Strickland standard is a gen
eral one, so the range of reasonable applications is sub
stantial. 556 U. S., at ___ (slip op., at 11). Federal habeas
courts must guard against the danger of equating unrea
sonableness under Strickland with unreasonableness
under §2254(d). When §2254(d) applies, the question is
not whether counsel’s actions were reasonable. The ques
tion is whether there is any reasonable argument that
counsel satisfied Strickland’s deferential standard.
                              A
  With respect to defense counsel’s performance, the
Court of Appeals held that because Richter’s attorney had
not consulted forensic blood experts or introduced expert
evidence, the California Supreme Court could not rea
sonably have concluded counsel provided adequate repre
sentation. This conclusion was erroneous.
                              1
   The Court of Appeals first held that Richter’s attorney
rendered constitutionally deficient service because he did
not consult blood evidence experts in developing the basic
strategy for Richter’s defense or offer their testimony as
part of the principal case for the defense. Strickland,
however, permits counsel to “make a reasonable decision
that makes particular investigations unnecessary.” 466
U. S., at 691. It was at least arguable that a reasonable
attorney could decide to forgo inquiry into the blood evi
dence in the circumstances here.
   Criminal cases will arise where the only reasonable and
available defense strategy requires consultation with
experts or introduction of expert evidence, whether pre
trial, at trial, or both. There are, however, “countless
ways to provide effective assistance in any given case.
Even the best criminal defense attorneys would not defend
                  Cite as: 562 U. S. ____ (2011)           17

                      Opinion of the Court

a particular client in the same way.” Id., at 689. Rare are
the situations in which the “wide latitude counsel must
have in making tactical decisions” will be limited to any
one technique or approach. Ibid. It can be assumed that
in some cases counsel would be deemed ineffective for
failing to consult or rely on experts, but even that formula
tion is sufficiently general that state courts would have
wide latitude in applying it. Here it would be well within
the bounds of a reasonable judicial determination for the
state court to conclude that defense counsel could follow a
strategy that did not require the use of experts regarding
the pool in the doorway to Johnson’s bedroom.
   From the perspective of Richter’s defense counsel when
he was preparing Richter’s defense, there were any num
ber of hypothetical experts—specialists in psychiatry,
psychology, ballistics, fingerprints, tire treads, physiology,
or numerous other disciplines and subdisciplines—whose
insight might possibly have been useful. An attorney can
avoid activities that appear “distractive from more impor
tant duties.” Bobby v. Van Hook, 558 U. S. ___, ___ (2009)
(per curiam) (slip op., at 8). Counsel was entitled to for
mulate a strategy that was reasonable at the time and to
balance limited resources in accord with effective trial
tactics and strategies. See Knowles, supra, at ___ (slip op.,
at 14–15); Rompilla v. Beard, 545 U. S. 374, 383 (2005);
Wiggins v. Smith, 539 U. S. 510, 525 (2003); Strickland,
466 U. S., at 699.
   In concluding otherwise the Court of Appeals failed to
“reconstruct the circumstances of counsel’s challenged
conduct” and “evaluate the conduct from counsel’s per
spective at the time.” Id., at 689. In its view Klein’s
location was “the single most critical issue in the case”
given the differing theories of the prosecution and the
defense, and the source of the blood in the doorway was
therefore of central concern. 578 F. 3d, at 953–954. But it
was far from a necessary conclusion that this was evident
18               HARRINGTON v. RICHTER

                     Opinion of the Court

at the time of the trial. There were many factual differ
ences between prosecution and defense versions of the
events on the night of the shootings. It is only because
forensic evidence has emerged concerning the source of the
blood pool that the issue could with any plausibility be
said to stand apart. Reliance on “the harsh light of hind
sight” to cast doubt on a trial that took place now more
than 15 years ago is precisely what Strickland and
AEDPA seek to prevent. Cone, 535 U. S., at 702; see also
Lockhart, 506 U. S., at 372.
  Even if it had been apparent that expert blood testi
mony could support Richter’s defense, it would be reason
able to conclude that a competent attorney might elect not
to use it. The Court of Appeals opinion for the en banc
majority rests in large part on a hypothesis that reasona
bly could have been rejected. The hypothesis is that with
out jeopardizing Richter’s defense, an expert could have
testified that the blood in Johnson’s doorway could not
have come from Johnson and could have come from Klein,
thus suggesting that Richter’s version of the shooting was
correct and Johnson’s a fabrication. This theory overlooks
the fact that concentrating on the blood pool carried its
own serious risks. If serological analysis or other forensic
evidence demonstrated that the blood came from Johnson
alone, Richter’s story would be exposed as an invention.
An attorney need not pursue an investigation that would
be fruitless, much less one that might be harmful to the
defense. Strickland, supra, at 691. Here Richter’s attor
ney had reason to question the truth of his client’s ac
count, given, for instance, Richter’s initial denial of
involvement and the subsequent production of Johnson’s
missing pistol.
  It would have been altogether reasonable to conclude
that this concern justified the course Richter’s counsel
pursued. Indeed, the Court of Appeals recognized this risk
insofar as it pertained to the suggestion that counsel
                  Cite as: 562 U. S. ____ (2011)           19

                      Opinion of the Court

should have had the blood evidence tested. 578 F. 3d, at
956, n. 9. But the court failed to recognize that making a
central issue out of blood evidence would have increased
the likelihood of the prosecution’s producing its own evi
dence on the blood pool’s origins and composition; and
once matters proceeded on this course, there was a serious
risk that expert evidence could destroy Richter’s case.
Even apart from this danger, there was the possibility
that expert testimony could shift attention to esoteric
matters of forensic science, distract the jury from whether
Johnson was telling the truth, or transform the case into a
battle of the experts. Accord, Bonin v. Calderon, 59 F. 3d
815, 836 (CA9 1995).
   True, it appears that defense counsel’s opening state
ment itself inspired the prosecution to introduce expert
forensic evidence. But the prosecution’s evidence may
well have been weakened by the fact that it was assem
bled late in the process; and in any event the prosecution’s
response shows merely that the defense strategy did not
work out as well as counsel had hoped, not that counsel
was incompetent.
   To support a defense argument that the prosecution has
not proved its case it sometimes is better to try to cast
pervasive suspicion of doubt than to strive to prove a
certainty that exonerates. All that happened here is that
counsel pursued a course that conformed to the first op
tion. If this case presented a de novo review of Strickland,
the foregoing might well suffice to reject the claim of
inadequate counsel, but that is an unnecessary step. The
Court of Appeals must be reversed if there was a reason
able justification for the state court’s decision. In light of
the record here there was no basis to rule that the state
court’s determination was unreasonable.
   The Court of Appeals erred in dismissing strategic
considerations like these as an inaccurate account of
counsel’s actual thinking. Although courts may not in
20                HARRINGTON v. RICHTER

                     Opinion of the Court

dulge “post hoc rationalization” for counsel’s decisionmak
ing that contradicts the available evidence of counsel’s
actions, Wiggins, 539 U. S., at 526–527, neither may they
insist counsel confirm every aspect of the strategic basis
for his or her actions. There is a “strong presumption”
that counsel’s attention to certain issues to the exclusion
of others reflects trial tactics rather than “sheer neglect.”
Yarborough v. Gentry, 540 U. S. 1, 8 (2003) (per curiam).
After an adverse verdict at trial even the most experienced
counsel may find it difficult to resist asking whether a
different strategy might have been better, and, in the
course of that reflection, to magnify their own responsibil
ity for an unfavorable outcome. Strickland, however, calls
for an inquiry into the objective reasonableness of coun
sel’s performance, not counsel’s subjective state of mind.
466 U. S., at 688.
                              2
   The Court of Appeals also found that Richter’s attorney
was constitutionally deficient because he had not expected
the prosecution to offer expert testimony and therefore
was unable to offer expert testimony of his own in re
sponse.
   The Court of Appeals erred in suggesting counsel had
to be prepared for “any contingency,” 578 F. 3d, at 946
(internal quotation marks omitted).        Strickland does
not guarantee perfect representation, only a “ ‘reasonably
competent attorney.’ ” 466 U. S., at 687 (quoting McMann
v. Richardson, 397 U. S. 759, 770 (1970)); see also Gentry,
supra, at 7. Representation is constitutionally ineffective
only if it “so undermined the proper functioning of the
adversarial process” that the defendant was denied a fair
trial. Strickland, supra, at 686. Just as there is no expec
tation that competent counsel will be a flawless strategist
or tactician, an attorney may not be faulted for a reason
able miscalculation or lack of foresight or for failing to
                 Cite as: 562 U. S. ____ (2011)           21

                     Opinion of the Court

prepare for what appear to be remote possibilities.
   Here, Richter’s attorney was mistaken in thinking the
prosecution would not present forensic testimony. But the
prosecution itself did not expect to make that presenta-
tion and had made no preparations for doing so on the eve
of trial. For this reason alone, it is at least debatable
whether counsel’s error was so fundamental as to call the
fairness of the trial into doubt.
   Even if counsel should have foreseen that the prosecu
tion would offer expert evidence, Richter would still need
to show it was indisputable that Strickland required his
attorney to act upon that knowledge. Attempting to estab
lish this, the Court of Appeals held that defense counsel
should have offered expert testimony to rebut the evidence
from the prosecution. But Strickland does not enact New
ton’s third law for the presentation of evidence, requiring
for every prosecution expert an equal and opposite expert
from the defense.
   In many instances cross-examination will be sufficient
to expose defects in an expert’s presentation. When de
fense counsel does not have a solid case, the best strategy
can be to say that there is too much doubt about the
State’s theory for a jury to convict. And while in some
instances “even an isolated error” can support an ineffec
tive-assistance claim if it is “sufficiently egregious and
prejudicial,” Murray v. Carrier, 477 U. S. 478, 496 (1986),
it is difficult to establish ineffective assistance when coun
sel’s overall performance indicates active and capable
advocacy. Here Richter’s attorney represented him with
vigor and conducted a skillful cross-examination. As
noted, defense counsel elicited concessions from the State’s
experts and was able to draw attention to weaknesses in
their conclusions stemming from the fact that their analy
ses were conducted long after investigators had left the
crime scene. For all of these reasons, it would have been
reasonable to find that Richter had not shown his attorney
22               HARRINGTON v. RICHTER

                     Opinion of the Court

was deficient under Strickland.
                             B
   The Court of Appeals further concluded that Richter had
established prejudice under Strickland given the expert
evidence his attorney could have introduced. It held that
the California Supreme Court would have been unreason
able in concluding otherwise. This too was error.
   In assessing prejudice under Strickland, the question is
not whether a court can be certain counsel’s performance
had no effect on the outcome or whether it is possible a
reasonable doubt might have been established if counsel
acted differently. See Wong v. Belmontes, 558 U. S. ___,
___ (2009) (per curiam) (slip op., at 13); Strickland, 466
U. S., at 693. Instead, Strickland asks whether it is “rea
sonably likely” the result would have been different. Id.,
at 696. This does not require a showing that counsel’s
actions “more likely than not altered the outcome,” but the
difference between Strickland’s prejudice standard and a
more-probable-than-not standard is slight and matters
“only in the rarest case.” Id., at 693, 697. The likelihood
of a different result must be substantial, not just conceiv
able. Id., at 693.
   It would not have been unreasonable for the California
Supreme Court to conclude Richter’s evidence of prejudice
fell short of this standard. His expert serology evidence
established nothing more than a theoretical possibility
that, in addition to blood of Johnson’s type, Klein’s blood
may also have been present in a blood sample taken near
the bedroom doorway pool. At trial, defense counsel ex
tracted a concession along these lines from the prosecu
tion’s expert. The pathology expert’s claim about the size
of the blood pool could be taken to suggest only that the
wounded and hysterical Johnson erred in his assessment
of time or that he bled more profusely than estimated.
And the analysis of the purported blood pattern expert
                 Cite as: 562 U. S. ____ (2011)          23

                     Opinion of the Court

indicated no more than that Johnson was not standing up
when the blood pool formed.
   It was also reasonable to find Richter had not estab
lished prejudice given that he offered no evidence directly
challenging other conclusions reached by the prosecution’s
experts. For example, there was no dispute that the blood
sample taken near the doorway pool matched Johnson’s
blood type. The California Supreme Court reasonably
could have concluded that testimony about patterns that
form when blood drips to the floor or about the rate at
which Johnson was bleeding did not undermine the re
sults of chemical tests indicating blood type. Nor did
Richter provide any direct refutation of the State’s expert
testimony describing how blood spatter near the couch
suggested a shooting in the living room and how the blood
patterns on Klein’s face were inconsistent with Richter’s
theory that Klein had been killed in the bedroom doorway
and moved to the couch.
   There was, furthermore, sufficient conventional circum
stantial evidence pointing to Richter’s guilt. It included
the gun safe and ammunition found at his home; his flight
from the crime scene; his disposal of the .32-caliber gun
and of Johnson’s pistol; his shifting story concerning his
involvement; the disappearance prior to the arrival of the
law enforcement officers of the .22-caliber weapon that
killed Klein; the improbability of Branscombe’s not being
wounded in the shootout that resulted in a combined four
bullet wounds to Johnson and Klein; and the difficulties
the intoxicated and twice-shot Johnson would have had in
carrying the body of a dying man from bedroom doorway
to living room couch, not to mention the lack of any obvi
ous reason for him to do so. There was ample basis for the
California Supreme Court to think any real possibility of
Richter’s being acquitted was eclipsed by the remaining
evidence pointing to guilt.
24               HARRINGTON v. RICHTER

                     Opinion of the Court

                        *    *     *
   The California Supreme Court’s decision on the merits
of Richter’s Strickland claim required more deference than
it received. Richter was not entitled to the relief ordered
by the Court of Appeals. The judgment is reversed, and
the case is remanded for further proceedings consistent
with this opinion.
                                           It is so ordered.

  JUSTICE KAGAN took no part in the consideration or
decision of this case.
                 Cite as: 562 U. S. ____ (2011)            1

              GINSBURG, J., concurring in judgment

SUPREME COURT OF THE UNITED STATES
                          _________________

                          No. 09–587
                          _________________


  KELLY HARRINGTON, WARDEN, PETITIONER v. 

             JOSHUA RICHTER 

 ON WRIT OF CERTIORARI TO THE UNITED STATES COURT OF

            APPEALS FOR THE NINTH CIRCUIT

                      [January 19, 2011] 


   JUSTICE GINSBURG, concurring in the judgment.
   In failing even to consult blood experts in preparation
for the murder trial, Richter’s counsel, I agree with the
Court of Appeals, “was not functioning as the ‘counsel’
guaranteed the defendant by the Sixth Amendment.”
Strickland v. Washington, 466 U. S. 668, 687 (1984). The
strong force of the prosecution’s case, however, was not
significantly reduced by the affidavits offered in support of
Richter’s habeas petition. I would therefore not rank
counsel’s lapse “so serious as to deprive [Richter] of a fair
trial, a trial whose result is reliable.” Ibid. For that rea
son, I concur in the Court’s judgment.
