                 Cite as: 561 U. S. ____ (2010)            1

                          Per Curiam

SUPREME COURT OF THE UNITED STATES
     DEMARCUS ALI SEARS v. STEPHEN UPTON, 

                   WARDEN 

  ON PETITION FOR WRIT OF CERTIORARI TO THE SUPREME 

                  COURT OF GEORGIA

              No. 09–8854. Decided June 29, 2010 


   PER CURIAM.
   According to an expert who testified during state post
conviction relief, petitioner Demarcus A. Sears performs at
or below the bottom first percentile in several measures of
cognitive functioning and reasoning. The cause of this
abnormality appears to be significant frontal lobe brain
damage Sears suffered as a child, as well as drug and
alcohol abuse in his teens. But because—in the words of
the state trial court—his counsel conducted a penalty
phase investigation that was “on its face . . . constitution
ally inadequate,” App. to Pet. for Cert. 27B, evidence
relating to Sears’ cognitive impairments and childhood
difficulties was not brought to light at the time he was
sentenced to death.
   After finding constitutionally deficient attorney per
formance under the framework we set forth in Strickland
v. Washington, 466 U. S. 668 (1984), the state postconvic
tion court found itself unable to assess whether counsel’s
inadequate investigation might have prejudiced Sears.
App. to Pet. for Cert. 29B–30B. Because Sears’ counsel
did present some mitigation evidence during Sears’ pen
alty phase—but not the significant mitigation evidence a
constitutionally adequate investigation would have uncov
ered—the state court determined it could not speculate as
to what the effect of additional evidence would have been.
Id., at 30B. Accordingly, it denied Sears postconviction
relief. Id., at 34B. Thereafter, the Supreme Court of
Georgia summarily denied review of his claims. Id., at 1A.
2                           SEARS v. UPTON

                               Per Curiam

  For the reasons that follow, it is plain from the face of
the state court’s opinion that it failed to apply the correct
prejudice inquiry we have established for evaluating
Sears’ Sixth Amendment claim. We therefore grant the
petition for writ of certiorari, vacate the judgment, and
remand for further proceedings not inconsistent with this
opinion.1
                               I
   In 1993, a Georgia jury convicted Sears of armed rob
bery and kidnaping with bodily injury (which also resulted
in death), a capital crime under state law. See Ga. Code
Ann. §16–5–40(d)(4) (2006).2 During the penalty phase of
Sears’ capital trial, his counsel presented evidence describ
ing his childhood as stable, loving, and essentially without
incident. Seven witnesses offered testimony along the
following lines: Sears came from a middle-class back
ground; his actions shocked and dismayed his relatives;
and a death sentence, the jury was told, would devastate
the family. See Pet. for Cert. 6–7. Counsel’s mitigation
——————
  1 Although this is a state-court decision, it resolved a federal issue on

exclusively federal-law grounds. We therefore have jurisdiction. 28
U. S. C. §1257; see also Padilla v. Kentucky, 559 U. S. ___ (2010)
(reviewing state postconviction decision raising Sixth Amendment
question).
  2 Sears was sentenced to death for the Kentucky murder of a woman

whom he and an accomplice kidnaped in Georgia. Under Georgia law,
a jury may “impose a death sentence for the offense of kidnapping with
bodily injury on the ground that the offense of kidnapping with bodily
injury was committed while the offender was engaged in the commis
sion of the capital felon[y] of murder . . . .” Potts v. State, 261 Ga. 716,
720, 410 S. E. 2d 89, 93 (1991). So long as “the murder . . . [is] suffi
ciently a part of the same criminal transaction,” it may count as a
“statutory aggravating circumstanc[e] of the offense of kidnapping with
bodily injury.” Ibid., 410 S. E. 2d, at 94. Sears has raised a categorical
Eighth Amendment challenge to the constitutionality of his death
sentence for a kidnaping offense, which we decline to reach. And any
jurisdictional or constitutional issue with respect to Georgia’s ability to
execute Sears for a murder occurring in Kentucky is not before us.
                     Cite as: 561 U. S. ____ (2010)                    3

                              Per Curiam

theory, it seems, was calculated to portray the adverse
impact of Sears’ execution on his family and loved ones.
20 Record 5181. But the strategy backfired. The prosecu
tor ultimately used the evidence of Sears’ purportedly
stable and advantaged upbringing against him during the
State’s closing argument. With Sears, the prosecutor told
the jury, “[w]e don’t have a deprived child from an inner
city; a person who[m] society has turned its back on at an
early age. But, yet, we have a person, privileged in every
way, who has rejected every opportunity that was afforded
him.” Pet. for Cert. 7 (quoting trial transcript; internal
quotation marks omitted).
   The mitigation evidence that emerged during the state
postconviction evidentiary hearing, however, demon
strates that Sears was far from “privileged in every way.”
Sears’ home life, while filled with material comfort, was
anything but tranquil: His parents had a physically abu
sive relationship, Exh. 26, 6 Record 1676 (Affidavit of
Demetrius A. Sears), and divorced when Sears was young,
Exh. 22, id., at 1654 (Affidavit of Virginia Sears Graves);
he suffered sexual abuse at the hands of an adolescent
male cousin, Exh. 26, id., at 1681–1682; his mother’s
“favorite word for referring to her sons was ‘little mother
fuckers,’ ” Exh. 3, 2 Record 265 (Affidavit of Richard G.
Dudley, Jr., MD); and his father was “verbally abusive,”
Exh. 37, 6 Record 1746–1747 (Affidavit of Carol Becci-
Youngs),3 and disciplined Sears with age-inappropriate

——————
  3 In the particular instance recounted in this affidavit, Sears’ art

teacher stated that his father “berate[d] [him] in front of” the school
principal and her during a parent-teacher conference. Exh. 37, 6 Record
1746. The event was significant: “I’ll never forget the way he bullied
him,” the art teacher explained, “Mr. Sears was so verbally abusive and
made such a scene, that it made everyone in the room uncomfortable.”
Ibid. The art teacher had “never been in a conference where a parent
severely criticized a child in the presence of his teachers and meant it,
as Mr. Sears did.” Id., at 1747.
4                     SEARS v. UPTON

                         Per Curiam

military-style drills, Exh. 3, 2 Record 263–264; Exh. 19, 6
Record 1622 (Affidavit of Frank Sears); Exh. 22, id., at
1651; Exh. 28, id., at 1694 (Affidavit of Kenneth Burns,
Sr.). Sears struggled in school, demonstrating substantial
behavior problems from a very young age. For example,
Sears repeated the second grade, Exh. 6, 3 Record 500–
501, and was referred to a local health center for evalua
tion at age nine, Exh. 7, id., at 503, 504, 508. By the time
Sears reached high school, he was “described as severely
learning disabled and as severely behaviorally handi
capped.” Exh. A to Exh. 1, 2 Record 174–176 (Affidavit of
Tony L. Strickland, M. S., Ph. D.).
   Environmental factors aside, and more significantly,
evidence produced during the state postconviction relief
process also revealed that Sears suffered “significant
frontal lobe abnormalities.” Exh. 1, id., at 147. Two dif
ferent psychological experts testified that Sears had sub
stantial deficits in mental cognition and reasoning—i.e.,
“problems with planning, sequencing and impulse control,”
ibid.—as a result of several serious head injuries he suf
fered as a child, as well as drug and alcohol abuse. See 1
Record 37–40 (Testimony of Dr. Strickland); id., at 95–96
(Testimony of Dr. Dudley). Regardless of the cause of his
brain damage, his scores on at least two standardized
assessment tests placed him at or below the first percen
tile in several categories of cognitive function, “making
him among the most impaired individuals in the popula
tion in terms of ability to suppress competing impulses
and conform behavior only to relevant stimuli.” Exh. 1, 2
Record 148; see also 1 Record 37. The assessment also
revealed that Sears’ “ability to organize his choices, assign
them relative weight and select among them in a deliber
ate way is grossly impaired.” Exh. 1, 2 Record 149. From
an etiological standpoint, one expert explained that Sears’
“history is replete with multiple head trauma, substance
abuse and traumatic experiences of the type expected” to
                     Cite as: 561 U. S. ____ (2010)                     5

                              Per Curiam

lead to these significant impairments. Id., at 150; see also
1 Record 44.
   Whatever concern the dissent has about some of the
sources relied upon by Sears’ experts—informal personal
accounts, see post, at 5–7 (opinion of SCALIA, J.)—it does
not undermine the well-credentialed expert’s assessment,4
based on between 12 and 16 hours of interviews, testing,
and observations, see 1 Record 32, that Sears suffers from
substantial cognitive impairment. Sears performed dis
mally on several of the forensic tests administered to him
to assess his frontal lobe functioning. On the Stroop Word
Interference Test, which measures response inhibition, id.,
at 36–37, 99.6% of those individuals in his cohort (which
accounts for age, education, and background) performed
better than he did. Ibid. On the Trail-Making B test,
which also measures frontal lobe functioning, id., at 37–
38, Sears performed at the first (and lowest) percentile.
Id., at 38. Based on these results, the expert’s first-hand
observations, and an extensive review of Sears’ personal
history, the expert’s opinion was unequivocal: There is
“clear and compelling evidence” that Sears has “pro
nounced frontal lobe pathology.”5 Id., at 68.
——————
   4 Dr. Strickland, a psychologist, is the director of a mild head injury

clinic and the Sports Concussion Institute at Centinella Freeman
Medical Center in Los Angeles. 1 Record 30. He is an associate profes
sor of psychiatry in residence at the University of California at Los
Angeles and directs a memory disorder and cerebral palsy clinic for
that university’s department of neuroscience. Id., at 30–31. The State
had no objection to his being tendered as an expert in neuropsychology.
Id., at 31.
   5 During a colloquy with the court, Dr. Strickland further explained:

   “THE COURT: But by taking some history of head injuries, coupled
with the results of the tests that you’ve given, you can comfortably
conclude that the results of the tests that you’ve given were a conse
quence of frontal lobe head injuries?
   “THE WITNESS: Absolutely. And, moreover, Your Honor, the
patient has a lesion on the front of his head, which is something I can
observe.” Id., at 78.
6                          SEARS v. UPTON

                               Per Curiam

  Further, the fact that Sears’ brother is a convicted drug
dealer and user, and introduced Sears to a life of crime, 6
Record 1683–1686, actually would have been consistent
with a mitigation theory portraying Sears as an individual
with diminished judgment and reasoning skills, who may
have desired to follow in the footsteps of an older brother
who had shut him out of his life. Post, at 6. And the fact
that some of such evidence may have been “hearsay” does
not necessarily undermine its value—or its admissibility—
for penalty phase purposes.6 Post, at 5, n. 3.
  Finally, the fact that along with this new mitigation
evidence there was also some adverse evidence is unsur
prising, post, at 7, given that counsel’s initial mitigation
investigation was constitutionally inadequate. Competent
counsel should have been able to turn some of the adverse
evidence into a positive—perhaps in support of a cognitive
deficiency mitigation theory. In particular, evidence of
Sears’ grandiose self-conception and evidence of his magi
cal thinking, ibid., were features, in another well
credentialed expert’s view,7 of a “profound personality
——————
    6 LikeGeorgia’s “necessity exception” to its hearsay rules, see Ga.
Code Ann. §24–3–1(b) (2006), we have also recognized that reliable
hearsay evidence that is relevant to a capital defendant’s mitigation
defense should not be excluded by rote application of a state hearsay
rule. See Green v. Georgia, 442 U. S. 95, 97 (1979) (per curiam) (“Re
gardless of whether the proffered testimony comes within Georgia’s
hearsay rule, under the facts of this case its exclusion constituted a
violation of the Due Process Clause . . . . The excluded testimony was
highly relevant to a critical issue in the punishment phase of the trial”);
see also Chambers v. Mississippi, 410 U. S. 284, 302 (1973) (“In these
circumstances, where constitutional rights directly affecting the ascer
tainment of guilt are implicated, the hearsay rule may not be applied
mechanistically to defeat the ends of justice”). We take no view on
whether the evidence at issue would satisfy the considerations we set
forth in Green, or would be otherwise admissible under Georgia law.
   7 Dr. Dudley, a psychiatrist, completed his internship and residency

at Northwestern University Medical Center, and has been board
certified in psychiatry by the American Board of Psychiatry and Neu
                     Cite as: 561 U. S. ____ (2010)                   7

                              Per Curiam

disorder.” 1 Record 104. 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 horren
dous acts—especially in light of his purportedly stable
upbringing.
   Because they failed to conduct an adequate mitigation
investigation, none of this evidence was known to Sears’
trial counsel. It emerged only during state postconviction
relief.
                             II
   Unsurprisingly, the state postconviction trial court
concluded that Sears had demonstrated his counsel’s
penalty phase investigation was constitutionally deficient.
See Strickland, 466 U. S., at 688 (explaining that first
inquiry when evaluating Sixth Amendment ineffectiveness
claim is whether counsel’s representation “fell below an
objective standard of reasonableness”). In its view, the
cursory nature of counsel’s investigation into mitigation
evidence—“limited to one day or less, talking to witnesses
selected by [Sears’] mother”—was “on its face . . . constitu
tionally inadequate.” App. to Pet. for Cert. 27B.
   What is surprising, however, is the court’s analysis
regarding whether counsel’s facially inadequate mitigation
investigation prejudiced Sears. See Strickland, supra, at
694. Although the court appears to have stated the proper
prejudice standard,8 it did not correctly conceptualize how
that standard applies to the circumstances of this case.
——————
rology for more than 35 years. 1 Record 91–92. The State also had no
objection to his being tendered as an expert in psychiatry. Id., at 93.
  8 The court asked whether “there is a reasonable likelihood that the

outcome of his trial would have been different if his counsel had done
more investigation.” App. to Pet. for Cert. 29B–30B; see Strickland,
466 U. S., at 694 (“The 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. A reasonable probability is a
probability sufficient to undermine confidence in the outcome”).
8                          SEARS v. UPTON

                               Per Curiam

Because Sears’ counsel did present some mitigation evi
dence during his penalty phase, the court concluded that
“[t]his case cannot be fairly compared with those where
little or no mitigation evidence is presented and where a
reasonable prediction of outcome can be made.” App. to
Pet. for Cert. 30B. The court explained that “it is impossi
ble to know what effect [a different mitigation theory]
would have had on [the jury].” Ibid. “Because counsel put
forth a reasonable theory with supporting evidence,” the
court reasoned, “[Sears] . . . failed to meet his burden of
proving that there is a reasonable likelihood that the
outcome at trial would have been different if a different
mitigation theory had been advanced.”9 Ibid.
   There are two errors in the state court’s analysis of
Sears’ Sixth Amendment claim. First, the court curtailed
a more probing prejudice inquiry because it placed undue
reliance on the assumed reasonableness of counsel’s miti
gation theory. The court’s determination that counsel had
conducted a constitutionally deficient mitigation investi
gation, should have, at the very least, called into question
the reasonableness of this theory. Cf. Wiggins v. Smith,
539 U. S. 510, 522 (2003) (explaining that “counsel’s fail
ure to uncover and present voluminous mitigating evi
dence at sentencing could not be justified as a tactical
decision . . . because counsel had not ‘fulfill[ed] their obli
——————
  9 Channeling powers of telepathy, JUSTICE SCALIA asserts that what

the trial court actually decided in this case is that “Sears’ trial counsel
presented a reasonable mitigation theory and offered evidence suffi
cient to support it, so the prejudice inquiry was more difficult—so
difficult that Sears could not make the requisite showing.” Post, at 4.
Such a highly favorable reading of the trial court’s analysis would be
far more convincing had the trial court engaged with the evidence as
JUSTICE SCALIA does. But it offered no such analysis in its opinion;
indeed, it appears the court did not even conduct any real analysis,
explaining that it was “impossible to know what effect” the evidence
might have had on the jury. App. to Pet. for Cert. 30B (emphasis
added).
                     Cite as: 561 U. S. ____ (2010)                    9

                              Per Curiam

gation to conduct a thorough investigation of the defen
dant’s background’ ” (quoting Williams v. Taylor, 529 U. S.
362, 396 (2000); alteration in original)). And, more to the
point, that a theory might be reasonable, in the abstract,
does not obviate the need to analyze whether counsel’s
failure to conduct an adequate mitigation investigation
before arriving at this particular theory prejudiced Sears.
The “reasonableness” of counsel’s theory was, at this stage
in the inquiry, beside the point: Sears might be prejudiced
by his counsel’s failures, whether his haphazard choice
was reasonable or not.
   JUSTICE SCALIA chides the Court for concluding that the
trial court assumed, rather than found, that counsel’s
mitigation theory was a reasonable one. Post, at 2. But
our point is that any finding with respect to the reason
ableness of the mitigation theory counsel utilized—in this
case, family impact—is in tension with the trial court’s
unambiguous finding that counsel’s investigation was
itself so unreasonable as to be facially unconstitutional.
This point is plain in Williams: We rejected any suggestion
that a decision to focus on one potentially reasonable trial
strategy—in that case, petitioner’s voluntary confession—
was “justified by a tactical decision” when “counsel did not
fulfill their obligation to conduct a thorough investigation
of the defendant’s background.” 529 U. S., at 396. A
“tactical decision” is a precursor to concluding that coun
sel has developed a “reasonable” mitigation theory in a
particular case.10
——————
  10 Moreover, the reasonableness of the theory is not relevant when
evaluating the impact of evidence that would have been available and
likely introduced, had counsel completed a constitutionally adequate
investigation before settling on a particular mitigation theory. This
point was also plain in Williams: “Whether or not . . . omissions [in the
investigation] were sufficiently prejudicial to have affected the outcome
of sentencing,” they may nevertheless demonstrate deficiency. 529
U. S., at 396. The one inquiry, deficient mitigation investigation, is
10                        SEARS v. UPTON

                             Per Curiam

   Second, and more fundamentally, the court failed to
apply the proper prejudice inquiry. We have never limited
the prejudice inquiry under Strickland to cases in which
there was only “little or no mitigation evidence” presented,
App. to Pet. for Cert. 30B. True, we have considered cases
involving such circumstances,11 and we have explained
that there is no prejudice when the new mitigating evi
dence “would barely have altered the sentencing profile
presented” to the decisionmaker, Strickland, supra, at
700. But we also have found deficiency and prejudice in
other cases in which counsel presented what could be
described as a superficially reasonable mitigation theory
during the penalty phase. E.g., Williams, supra, at 398
(remorse and cooperation with police); Rompilla v. Beard,
545 U. S. 374, 378 (2005) (residual doubt). We did so most
recently in Porter v. McCollum, 558 U. S. ___, ___ (2009)
(per curiam) (slip op., at 3), where counsel at trial had
attempted to blame his client’s bad acts on his drunken
ness, and had failed to discover significant mitigation
evidence relating to his client’s heroic military service and
substantial mental health difficulties that came to light
only during postconviction relief, id., at ___ (slip op., at
11–12). Not only did we find prejudice in Porter, but—
bound by deference owed under 28 U. S. C. §2254(d)(1)—
we also concluded the state court had unreasonably ap
plied Strickland’s prejudice prong when it analyzed Por
ter’s claim. Porter, supra, at ___ (slip op., at 13).
   We certainly have never held that counsel’s effort to
present some mitigation evidence should foreclose an
inquiry into whether a facially deficient mitigation inves
tigation might have prejudiced the defendant. To the
contrary, we have consistently explained that the Strick
——————
distinct from the second, whether there was prejudice as a result.
  11See, e.g., Wiggins v. Smith, 539 U. S. 510, 515–516 (2003); Strick

land v. Washington, 466 U. S. 668, 700 (1984).
                     Cite as: 561 U. S. ____ (2010) 	                 11

                              Per Curiam

land inquiry requires precisely the type of probing and
fact-specific analysis that the state trial court failed to
undertake below.12 In the Williams decision, for instance,
we categorically rejected the type of truncated prejudice
inquiry undertaken by the state court in this case. 529
U. S., at 397–398. And, in Porter, we recently explained:
                   	
     “To assess [the] probability [of a different outcome
     under Strickland], we consider the totality of the
     available mitigation evidence—both that adduced at
     trial, and the evidence adduced in the habeas proceed
     ing—and reweig[h] it against the evidence in aggrava
     tion.” 558 U. S., at ____ (slip op., at 11) (internal quo
     tation marks omitted; third alteration in original).
That same standard applies—and will necessarily require
a court to “speculate” as to the effect of the new evidence—
regardless of how much or how little mitigation evidence
was presented during the initial penalty phase. Indeed, it
is exactly this kind of probing inquiry that JUSTICE SCALIA
now undertakes, post, at 4–8, and that the trial court
failed to do. In all circumstances, this is the proper preju
dice standard for evaluating a claim of ineffective repre
sentation in the context of a penalty phase mitigation
investigation.

——————
   12 Whether it did so implicitly is far from apparent, notwithstanding

JUSTICE SCALIA’s suggestion to the contrary. See post, at 3–4. The trial
court stated that the record was “largely silent” on “what [evidence]
would have been shown if [additional mitigating evidence] had been
sought.” App. to Pet. for Cert. 28B. This is a curious assertion in light
of the 22 volumes of evidentiary hearing transcripts and submissions in
the record, which spell out the findings discussed above. It also un
dermines any suggestion that the court did, in fact, do the reweighing
JUSTICE SCALIA believes it undertook; it is plain the record is not
“largely silent.” And it also undermines any suggestion that the court
simply discounted the value of the testimony; had it made any such
finding, the court could have easily stated, instead, that the record
evidence was unpersuasive.
12                    SEARS v. UPTON 


                         Per Curiam


                              III 

  A proper analysis of prejudice under Strickland would
have taken into account the newly uncovered evidence of
Sears’ “significant” mental and psychological impairments,
along with the mitigation evidence introduced during
Sears’ penalty phase trial, to assess whether there is a
reasonable probability that Sears would have received a
different sentence after a constitutionally sufficient miti
gation investigation. See Porter, supra, at ___ (slip op., at
11); Williams, supra, at 397–398; Strickland, supra, at
694. It is for the state court—and not for either this Court
or even JUSTICE SCALIA—to undertake this reweighing in
the first instance.
  Accordingly, the petition for certiorari and the motion
for leave to proceed in forma pauperis are granted. The
judgment below is vacated, and the case is remanded for
further proceedings not inconsistent with this opinion.

                                             It is so ordered.

  THE CHIEF JUSTICE and JUSTICE ALITO would deny the
petition for a writ of certiorari.
                 Cite as: 561 U. S. ____ (2010)           1

                     SCALIA, J., dissenting

SUPREME COURT OF THE UNITED STATES
     DEMARCUS ALI SEARS v. STEPHEN UPTON, 

                   WARDEN 

  ON PETITION FOR WRIT OF CERTIORARI TO THE SUPREME 

                  COURT OF GEORGIA

              No. 09–8854. Decided June 29, 2010 


   JUSTICE SCALIA, with whom JUSTICE THOMAS joins,
dissenting.
   The Court concludes, ante, at 7–12, that the Superior
Court of Butts County, Georgia, made errors of law in
applying the prejudice inquiry for ineffective-assistance-of
counsel claims under Strickland v. Washington, 466 U. S.
668 (1984). In my view there was no error of law, and the
Court today remands for the state court to do what it has
already done: find no reasonable likelihood that the miti
gation evidence the Court details in its opinion would have
persuaded a jury to change its mind about the death sen
tence for this brutal rape-murder.
   The state habeas court responsibly executed the first
step in the Strickland analysis, finding that the investiga
tion of mitigation evidence by Sears’ trial counsel was
deficient performance. The issue here is the second step:
whether Sears was prejudiced by that deficiency. As the
Court acknowledges, ante, at 7, the state habeas court
correctly stated the prejudice standard under Strickland:
The defendant has the burden to establish “a reasonable
probability that, but for counsel’s deficient performance,
the result of the proceeding would have been different.”
App. to Pet. for Cert. 24B–25B (citing 466 U. S., at 688,
694). “When applied to the sentencing phase of death
penalty trials,” that means “a reasonable probability that,
absent [counsel’s] errors, the sentencer would have con
cluded that the balance of the aggravating and mitigating
circumstances did not warrant death.” App. to Pet. for
2                      SEARS v. UPTON

                     SCALIA, J., dissenting

Cert. 25B–26B.
   The Court today concludes that there were two errors in
the application of that proper standard. First, it reasons
that the court erroneously “curtailed a more probing
prejudice inquiry because it placed undue reliance on the
assumed reasonableness of counsel’s mitigation theory” at
trial. Ante, at 8. That argument is flawed on several
levels. To begin with, the state habeas court did not as
sume trial counsel’s mitigation theory was reasonable; it
found that it was. It said: “[A]lthough counsel failed to
investigate thoroughly, they did develop a reasonable
mitigation theory with evidence to support it.” App. to
Pet. for Cert. 30B. After interviews of roughly a dozen
potential mitigation witnesses, who, with the exception of
Sears’ father, gave positive accounts of Sears and his
family, see 7 Record 2025, 2051–2052; 8 id., at 2129,
2291–2344, Sears’ trial counsel developed a mitigation
theory that Sears came from a good family and had a solid
middle-class upbringing; that his offense was completely
out of character; that he cooperated with police; and that
sentencing Sears to death would devastate his family and
friends, see id., at 2124–2125; 19 id., at 4861–4862, 4916–
4917, 4954–4955; 20 id., at 5181. To support that ap
proach his attorneys called seven witnesses, including
Sears’ mother, four family friends, and his high school
guidance counselor. See Pet. for Cert. 6–7 (citing trial
transcript pages between 2375 and 2451). The state ha
beas court did not declare that this mitigation theory
“might be reasonable, in the abstract,” as the Court puts
it, ante, at 8. Rather, it concluded that counsel “put forth
a reasonable theory with supporting evidence.” App. to
Pet. for Cert. 30B.
   The Court’s argument is also flawed because the habeas
court’s reasonableness finding did not cause it to “curtai[l]”
its prejudice inquiry, or lead to the conclusion that it could
“obviate the need to analyze” whether pursuing a different
                      Cite as: 561 U. S. ____ (2010)                     3

                          SCALIA, J., dissenting

mitigation theory would have made a difference. Ante, at
9. The reasonableness finding merely meant that the
prejudice determination had to be made by asking, not
whether the jury’s mind would probably have been
changed by hearing Sears’ new mitigation theory instead
of hearing no mitigation theory at all; but rather whether
it would probably have been changed by substituting
Sears’ new mitigation theory for the reasonable mitigation
theory that was presented and rejected.1 After hearing all
the witnesses and other evidence Sears presented before
it, the state court concluded that “it is just not possible to
know what effect a different mitigation theory would have
had.” App. to Pet. for Cert. 30B (emphasis added).2
   The second, “and more fundamenta[l],” legal error the
Court alleges, ante, at 10–11, is really encased within the
first. The Court claims that the state habeas court “lim
ited the prejudice inquiry under Strickland to cases in
which there was only ‘little or no mitigation evidence’
presented.” Id., at 10 (quoting App. to Pet. for Cert. 30B).
The court erred, we are told, by determining that “pre
sent[ation of] some mitigation evidence should foreclose an
inquiry into whether” Sears was prejudiced. Ibid. That is
not a fair reading of the opinion. The state court did not
hold that a defendant could never suffer prejudice when
ever his counsel provided any mitigation evidence.
Rather, it stated that “[t]his case cannot be fairly com
——————
  1 The Court contends, ante, at 9, that there was a “tension” between
the state court’s conclusion that the investigation was deficient and its
conclusion that the mitigation theory presented to the jury was reason
able. This terribly misreads the state court’s opinion. It did not say (as
the Court’s point assumes) that counsel’s using the mitigation theory
they did was reasonable; it said that the theory itself was reasonable,
making it hard to say whether a different theory would have persuaded
the jury. This presents no conceivable “tension.”
  2 On the fair reading we owe the state court, its opinion provides no

basis for inferring that it failed to “engag[e] with the evidence” and “did
not even conduct any real analysis.” Ante, at 8, n. 8.
4                    SEARS v. UPTON

                    SCALIA, J., dissenting

pared with those where little or no mitigation evidence is
presented and where a reasonable prediction of outcome
can be made.” App. to Pet. for Cert. 30B (emphasis
added). That is absolutely correct. This case is not like
the prejudice cases on which the Court relies, where it
could readily be said that the overlooked mitigation theory
would have made a much deeper impression on the jury
than the utterly unsupported theory (or absence of any
theory) offered at trial. See Porter v. McCollum, 558 U. S.
___, ___ (2009) (per curiam) (slip op., at 12); Rompilla v.
Beard, 545 U. S. 374, 378, 393 (2005); Wiggins v. Smith,
539 U. S. 510, 515, 537 (2003); Williams v. Taylor, 529
U. S. 362, 369 (2000). Sears’ trial counsel presented a
reasonable mitigation theory and offered evidence suffi
cient to support it, so the prejudice inquiry was more
difficult—so difficult that Sears could not make the requi
site showing. Clearly referring to the evidence in this
particular case, the court said:
    “Although here, the Petitioner can argue that a prior
    appeal shows the difficulty one juror was having
    reaching the same verdict as the others, it is just not
    possible to know what effect a different mitigation
    theory would have had on her, just as it is impossible
    to know what effect it would have had on other ju
    rors.” App. to Pet. for Cert. 30B.
   Since the habeas court made no legal error en route to
its Strickland conclusion, the only basis for reversing the
judgment here would be disagreement with the conclusion
itself: that Sears had not established that his new mitiga
tion theory would probably have caused the jury to impose
a life sentence instead of death.
   The Court makes no attempt to contradict that conclu
sion. Doing so would require a fact-intensive inquiry into
the 22-volume record to measure the persuasiveness of the
evidence supporting Sears’ new mitigation theory—an
                     Cite as: 561 U. S. ____ (2010)                    5

                         SCALIA, J., dissenting

inquiry the Court purports to disavow, ante, at 12, but
nonetheless tendentiously undertakes, ante, at 3–6. The
reader might think the state habeas court’s conclusion
highly questionable from the Court’s account, which re
cites as solid all the evidence supporting Sears’ new miti
gation theory, see ante, at 3–7. It is far from solid. Some
is likely inadmissible as unreliable hearsay under Georgia
law, see Gissendaner v. State, 272 Ga. 704, 714, 532 S. E.
2d 677, 688–689 (2000); Gulley v. State, 271 Ga. 337, 347,
519 S. E. 2d 655, 664 (1999)—such as much of the evi
dence for the uncorroborated second-hand claim that
Sears “suffered sexual abuse at the hands of an adolescent
male cousin,” ante, at 3.3 Other evidence a competent
attorney would likely not have placed before the jury—
such as all the testimony about Sears’ childhood from his
brother Demetrius, an admitted drug dealer and drug
user, 6 Record 1682–1684, 1695, 1752, and a convicted
felon (for bank fraud, wire fraud, identity theft, and co
caine trafficking), id., at 1687. No juror would have been
impressed by such a character witness.
   Some of the evidence is incredible, such as the psychia
trist’s assertion that Sears had “substantial deficits in
mental cognition and reasoning . . . as a result of serious
——————
  3 The  Court’s reliance on Green v. Georgia, 442 U. S. 95, 97 (1979)
(per curiam), ante, at 6, n. 6, to suggest that this unreliable hearsay
would be admissible for sentencing purposes is entirely misplaced. In
Green, we held it violated constitutional due process to exclude testi
mony regarding a co-conspirator’s confession that he alone committed
the capital murder with which the defendant was charged. Our holding
depended on “th[e] unique circumstances” of the case: the testimony to
be used at sentencing was “highly relevant” and “substantial[ly]”
reliable as a statement against penal interest made to a close friend; it
was corroborated by “ample” evidence and was used by the State to
obtain a conviction in a separate trial against the co-conspirator. 442
U. S., at 97. Here there are no such circumstances. The testimony is
uncorroborated second-hand reporting from self-interested witnesses
that is unreliable and therefore likely inadmissible.
6                           SEARS v. UPTON

                           SCALIA, J., dissenting

head injuries he suffered as a child,” ante, at 4. The seri
ous head injuries consisted of Sears’ hitting his head at a
roller-skating rink sometime early in elementary school,
1 Record 76; 2 id., at 225, running into an end table as a
child, 6 id., at 1651, and getting hit with a golf club some
time later in elementary school, 1 id., at 79; 2 id., at 225.4
(The last of these major injuries might not have been
introduced anyway, since that would have provided the
prosecution an opportunity to refute both the extent of the
injury and the mercy-worthiness of Sears, by introducing
into evidence Sears’ boast that when he was 11 or 12 he
“beat the s*** out of” someone after he was hit on the head
with a golf club, 8 id., at 2195.) Likewise incredible was
the assertion that Demetrius “introduced Sears to a life of
crime,” ante, at 6. According to testimony on which the
Court relies, Demetrius would “never let [Sears] hang
around” with him and his drug-dealing friends. 6 Record
1685–1686.
  A jury also would have discredited the psychiatric tes
timony of Dr. Strickland that “[f]rom an etiological stand
point . . . Sears’ ‘history is replete with multiple head
trauma, substance abuse and traumatic experiences of the
type expected’ to lead to these significant [mental] im
pairments,” ante, at 4–5 (quoting 2 id., at 150). As already
noted, the evidence of brain-damaging trauma is nonexis
tent. The psychiatric testimony of Dr. Dudley relied upon
the self-interested reporting of Sears himself and the

——————
  4 There is an unsubstantiated claim from Sears himself, 8 Record

2195, that when he was a teenager he was hit with a “hatchet” above
his right eye. Of course, that is the same place where he collided with
an end table, 6 id., at 1651, leaving the “lesion”—better known as a
scar—on his head that Dr. Strickland noted, ante, at 5–6, n. 5 (quoting
1 Record 78). There is no corroborating evidence for this event: no
medical records, 1 id., at 77, no other apparent scars, 2 id., at 245; 6 id.,
at 1651, and, tellingly, no family or friends to confirm what surely
would have been memorable had it happened.
                 Cite as: 561 U. S. ____ (2010)            7

                     SCALIA, J., dissenting

testimony of his less-than-trustworthy brother, Demetrius,
see, e.g., 1 Record 122, 133. And then there are the unfa
vorable parts of Dr. Dudley’s testimony: Sears is a “narcis
sis[t],” id., at 135, with a “grandiose” opinion of himself,
id., at 98–99; 2 id., at 246. Dr. Dudley’s affidavit portrays
Sears as arrogant and self-centered, id., at 246, 247, and
notes what he termed Sears’ “fantastical” boasting of his
first sexual experience with a woman at the age of six and
his other “innumerable sexual experiences,” 1 id., at 98–
99, 100; 2 id., at 246–247. It is hard to see how it could be
thought probable that Sears’ so-called “magical thinking,”
1 id., at 84, would have helped his plea for leniency, see
ante, at 6–7. It seems to me more likely the jury would
conclude that Sears’ “profoun[d] personality disorder,”
1 Record 104, made him exactly the kind of person who
would commit heinous crimes in the future.
   And some of the evidence the Court recounts is so ut
terly unlikely to affect a jury’s determination that this
brutal murder deserved death that its recitation is just
plain hilarious. For example, the claim that Sears’ father
“was ‘verbally abusive,’ ” ante, at 3, resting on nothing
more than an art teacher’s recollection that Sears’ father
“severely criticized” him—“and meant it”!—at a conference
with the principal concerning his son’s poor academic
performance, 6 Record 1747; the claim that his father
“disciplined Sears with age-inappropriate military-style
drills,” ante, at 3–4, which consisted of positively Von-
Steubenesque acts such as dousing the kid with cold water
when he refused to get up for school, and making him run
extra laps after sports practices, 6 Record 1622; and the
claim that his mother’s “ ‘favorite word’ ”—actually three
words—to refer to her sons was scatological, ante, at 3
(quoting 2 Record 265).
   While the Court takes pain to describe all the elements
of Sears’ new mitigation theory, down to the silliest, it
does not trouble to describe the brutal circumstances of
8                          SEARS v. UPTON

                          SCALIA, J., dissenting

the crime—which are at least just as relevant to assessing
whether the different mitigation theory would probably
have altered the sentence. But the jury heard all about
them. See Sears v. State, 268 Ga. 759, 759–760, 493 S. E.
2d 180, 182 (1997). They heard Sears’ confession that he
kidnaped, raped, and murdered Gloria Wilbur, a 59-year
old wife and mother. Sears, carrying a briefcase contain
ing various instruments of mayhem—brass knuckles,
knives, and handcuffs—and his accomplice, Phillip Wil
liams, were surveying a supermarket parking lot on a
Sunday evening in October 1990, looking for a car to steal
to drive back home to Ohio from Georgia. As the victim
was putting her groceries in the trunk of her car, Sears
approached, punched her in the face with his brass knuck
les, shoved her into the car, and drove to pick up Williams.
Sears then handcuffed her and pulled her into the back
seat as Williams drove. After they passed into Tennessee,
Sears raped her. Later in the evening, after they had
crossed into Kentucky, Sears told Williams to stop the car.
Sears forced her, still handcuffed, into the woods by the
side of the highway as she begged for her life. After
throwing her on the ground, he stabbed her in the neck.
In his confession he showed no regret or remorse for his
heinous crimes.5
   I do not know how anyone could disagree with the ha
beas court’s conclusion that it is impossible to say that
substituting the “deprived-childhood-cum-brain-damage”
defense for the “good-middle-class-kid-who-made-a
mistake” defense would probably have produced a differ
ent verdict. I respectfully dissent.

——————
  5 The jury also heard from several corrections officers who testified

that while Sears was incarcerated awaiting trial and sentencing, he
racked up dozens of disciplinary infractions, including assaults on other
inmates. “ ‘Predatory,’ ” “ ‘[i]ncorrigible,’ ” and incapable of reform was
how they described him. 10 id., at 2951–2957; 19 id., at 4868.
