CONE v. BELL, WARDEN

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CONE v. BELL, WARDEN
certiorari to the united states court of appeals for
the sixth circuit
No. 07–1114. Argued December 9, 2008—Decided April 28, 2009
After the State discredited petitioner Cone’s defense that he killed two
people while suffering from acute psychosis caused by drug addiction, he
was convicted and sentenced to death. The Tennessee Supreme Court
affirmed on direct appeal, and the state courts denied postconviction
relief. Later, in a second petition for state postconviction relief, Cone
raised the claim that the State had violated Brady v. Maryland, 373
U. S. 83, by suppressing witness statements and police reports that
would have corroborated his insanity defense and bolstered his case in
mitigation of the death penalty. The postconviction court denied him a
hearing on the ground that the Brady claim had been previously deter
mined, either on direct appeal or in earlier collateral proceedings. The
State Court of Criminal Appeals affirmed. Cone then filed a petition
for a writ of habeas corpus in Federal District Court. That court de
nied relief, holding the Brady claim procedurally barred because the
state courts’ disposition rested on adequate and independent state
grounds: Cone had waived it by failing to present his claim in state
court. Even if he had not defaulted the claim, ruled the court, it would
fail on its merits because none of the withheld evidence would have cast
doubt on his guilt. The Sixth Circuit agreed with the latter conclusion,
but considered itself barred from reaching the claim’s merits because
the state courts had ruled the claim previously determined or waived
under state law.
Held:
1. The state courts’ rejection of Cone’s Brady claim does not rest
on a ground that bars federal review. Neither of the State’s asserted
justifications for such a bar—that the claim was decided by the State
Supreme Court on direct review or that Cone had waived it by never
properly raising it in state court—provides an independent and ade
quate state ground for denying review of Cone’s federal claim. The
state postconviction court’s denial of the Brady claim on the ground it
had been previously determined in state court rested on a false premise:
Cone had not presented the claim in earlier proceedings, and, conse
quently, the state courts had not passed on it. The Sixth Circuit’s rejec
tion of the claim as procedurally defaulted because it had been twice
presented to the Tennessee courts was thus erroneous. Also unpersua

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sive is the State’s alternative argument that federal review is barred
because the Brady claim was properly dismissed by the state postcon
viction courts as waived. Those courts held only that the claim had
been previously determined, and this Court will not second-guess their
judgment. Because the claim was properly preserved and exhausted
in state court, it is not defaulted. Pp. 464–469.
2. The lower federal courts failed to adequately consider whether the
withheld documents were material to Cone’s sentence. Both the quan
tity and quality of the suppressed evidence lend support to Cone’s trial
position that he habitually used excessive amounts of drugs, that his
addiction affected his behavior during the murders, and that the State’s
contrary arguments were false and misleading. Nevertheless, even
when viewed in the light most favorable to Cone, the evidence does not
sustain his insanity defense: His behavior before, during, and after the
crimes was inconsistent with the contention that he lacked substantial
capacity either to appreciate the wrongfulness of his conduct or to con
form it to the requirements of law. Because the likelihood that the
suppressed evidence would have affected the jury’s verdict on the insan
ity issue is remote, the Sixth Circuit did not err by denying habeas relief
on the ground that such evidence was immaterial to the jury’s guilt
finding. The same cannot be said of that court’s summary treatment of
Cone’s claim that the suppressed evidence would have influenced the
jury’s sentencing recommendation. Because the suppressed evidence
might have been material to the jury’s assessment of the proper punish
ment, a full review of that evidence and its effect on the sentencing
verdict is warranted. Pp. 469–475.
492 F. 3d 743, vacated and remanded.
Stevens, J., delivered the opinion of the Court, in which Kennedy,
Souter, Ginsburg, and Breyer, JJ., joined. Roberts, C. J., filed an
opinion concurring in the judgment, post, p. 476. Alito, J., filed an opin
ion concurring in part and dissenting in part, post, p. 478. Thomas, J.,
filed a dissenting opinion, in which Scalia, J., joined, post, p. 486.
Thomas C. Goldstein argued the cause for petitioner.
With him on the briefs were Patricia A. Millett, Amy Howe,
Kevin K. Russell, Pamela S. Karlan, Jeffrey L. Fisher, and
Paul R. Bottei.
Jennifer L. Smith, Associate Deputy Attorney General of
Tennessee, argued the cause for respondent. With her on

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the brief were Robert E. Cooper, Jr., Attorney General, and
Michael E. Moore, Solicitor General.*
Justice Stevens delivered the opinion of the Court.
The right to a fair trial, guaranteed to state criminal de
fendants by the Due Process Clause of the Fourteenth
Amendment, imposes on States certain duties consistent
with their sovereign obligation to ensure “that ‘justice shall
be done’ ” in all criminal prosecutions. United States v.
Agurs, 427 U. S. 97, 111 (1976) (quoting Berger v. United
States, 295 U. S. 78, 88 (1935)). In Brady v. Maryland, 373
U. S. 83 (1963), we held that when a State suppresses evi
dence favorable to an accused that is material to guilt or to
punishment, the State violates the defendant’s right to due
process, “irrespective of the good faith or bad faith of the
prosecution.” Id., at 87.
In this case, Gary Cone, a Vietnam veteran sentenced to
death, contends that the State of Tennessee violated his
right to due process by suppressing witness statements and
police reports that would have corroborated his trial defense
and bolstered his case in mitigation of the death penalty. At
his trial in 1982, Cone asserted an insanity defense, contend
ing that he had killed two people while suffering from acute
amphetamine psychosis, a disorder caused by drug addiction.
The State of Tennessee discredited that defense, alleging
that Cone’s drug addiction was “ ‘baloney.’ ” 492 F. 3d 743,
760 (CA6 2007) (Merritt, J., dissenting). Ten years later,
Cone learned that the State had suppressed evidence sup
porting his claim of drug addiction.
Cone presented his new evidence to the state courts in a
petition for postconviction relief, but the Tennessee courts
*Briefs of amici curiae urging reversal were filed for Former Prosecu
tors by Walter Dellinger and Sri Srinivasan; and for Veterans for
America by Donald B. Verrilli, Jr.
Kent S. Scheidegger filed a brief for the Criminal Justice Legal Founda
tion as amicus curiae urging affirmance.

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denied him a hearing on the ground that his Brady claim had
been “previously determined,” id., at 753 (majority opinion),
either on direct appeal from his conviction or in earlier col
lateral proceedings. On application for a writ of habeas cor
pus pursuant to 28 U. S. C. § 2254, the Federal District Court
concluded that the state courts’ disposition rested on an ade
quate and independent state ground that barred further re
view in federal court, and the Court of Appeals for the Sixth
Circuit agreed. Doubt concerning the correctness of that
holding, coupled with conflicting decisions from other Courts
of Appeals, prompted our grant of certiorari. 554 U. S. 916
(2008).
After a complete review of the trial and postconviction
proceedings, we conclude that the Tennessee courts’ rejec
tion of petitioner’s Brady claim does not rest on a ground
that bars federal review. Furthermore, although the Dis
trict Court and the Court of Appeals passed briefly on the
merits of Cone’s claim, neither court distinguished the mate
riality of the suppressed evidence with respect to Cone’s
guilt from the materiality of the evidence with respect to his
punishment. While we agree that the withheld documents
were not material to the question whether Cone committed
murder with the requisite mental state, the lower courts
failed to adequately consider whether that same evidence
was material to Cone’s sentence. Therefore, we vacate the
decision of the Court of Appeals and remand the case to the
District Court to determine in the first instance whether
there is a reasonable probability that the withheld evidence
would have altered at least one juror’s assessment of the
appropriate penalty for Cone’s crimes.
I
On the afternoon of Saturday, August 10, 1980, Cone
robbed a jewelry store in downtown Memphis, Tennessee.
Fleeing the scene by car, he led police on a high-speed chase

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into a residential neighborhood. Once there, he abandoned
his vehicle and shot a police officer.1 When a bystander
tried to impede his escape, Cone shot him, too, before escap
ing on foot.
A short time later, Cone tried to hijack a nearby car.
When that attempt failed (because the driver refused to sur
render his keys), Cone tried to shoot the driver and a hov
ering police helicopter before realizing he had run out of
ammunition. He then fled the scene. Although police con
ducted a thorough search, Cone was nowhere to be found.
Early the next morning, Cone reappeared in the same
neighborhood at the door of an elderly woman. He asked to
use her telephone, and when she refused, he drew a gun.
Before he was able to gain entry, the woman slammed the
door and called the police. By the time officers arrived,
however, Cone had once again disappeared.
That afternoon, Cone gained entry to the home of 93-year
old Shipley Todd and his wife, 79-year-old Cleopatra Todd.
Cone beat the couple to death with a blunt instrument and
ransacked the first floor of their home. Later, he shaved his
beard and escaped to the airport without being caught.
Cone then traveled to Florida, where he was arrested sev
eral days later after robbing a drugstore in Pompano Beach.
A Tennessee grand jury charged Cone with two counts of
first-degree murder, two counts of murder in the perpetra
tion of a burglary, three counts of assault with intent to mur
der, and one count of robbery by use of deadly force. At his
jury trial in 1982, Cone did not challenge the overwhelming
physical and testimonial evidence supporting the charges
against him. His sole defense was that he was not guilty by
reason of insanity.
1 From the abandoned vehicle, police recovered stolen jewelry, large
quantities of illegal and prescription drugs, and approximately $2,400 in
cash. Much of the cash was later connected to a grocery store robbery
that had occurred on the previous day.

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Cone’s counsel portrayed his client as suffering from se
vere drug addiction attributable to trauma Cone had experi
enced in Vietnam. Counsel argued that Cone had com
mitted his crimes while suffering from chronic amphetamine
psychosis, a disorder brought about by his drug abuse. That
defense was supported by the testimony of three witnesses.
First was Cone’s mother, who described her son as an honor
ably discharged Vietnam veteran who had changed following
his return from service. She recalled Cone describing “how
terrible” it had been to handle the bodies of dead soldiers,
and she explained that Cone slept restlessly and sometimes
“holler[ed]” in his sleep. Tr. 1643–1645 (Apr. 20, 1982).
She also described one occasion, following Cone’s return
from service, when a package was shipped to him that con
tained marijuana. Before the war, she asserted, Cone had
not used drugs of any kind.
Two expert witnesses testified on Cone’s behalf. Mat
thew Jaremko, a clinical psychologist, testified that Cone suf
fered from substance abuse and posttraumatic stress disor
ders related to his military service in Vietnam. Jaremko
testified that Cone had expressed remorse for the murders,
and he opined that Cone’s mental disorder rendered him sub
stantially incapable of conforming his conduct to the law.
Jonathan Lipman, a neuropharmacologist, recounted at
length Cone’s history of illicit drug use, which began after
Cone joined the Army and escalated to the point where Cone
was consuming “rather horrific” quantities of drugs daily.
App. 100. According to Lipman, Cone’s drug abuse had led
to chronic amphetamine psychosis, a disorder manifested
through hallucinations and ongoing paranoia that prevented
Cone from obeying the law and appreciating the wrongful
ness of his actions.
In rebutting Cone’s insanity defense the State’s strategy
throughout trial was to present Cone as a calculating, intelli
gent criminal who was fully in control of his decisions and
actions at the time of the crimes. A key component of that

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strategy involved discrediting Cone’s claims of drug use.2
Through cross-examination, the State established that both
defense experts’ opinions were based solely on Cone’s repre
sentations to them about his drug use rather than on any
independently corroborated sources, such as medical records
or interviews with family or friends. The prosecution also
adduced expert and lay testimony to establish that Cone was
not addicted to drugs and had acted rationally and intention
ally before, during, and after the Todd murders.
Particularly damaging to Cone’s defense was the testi
mony of rebuttal witness Ilene Blankman, who had spent
time with Cone several months before the murders and at
whose home Cone had stayed in the days leading up to his
arrest in Florida. Blankman admitted to being a former
heroin addict but testified that she no longer used drugs and
tried to stay away from people who did. She testified that
she had never seen Cone use drugs, had never observed
track marks on his body, and had never seen him exhibit
signs of paranoia.
Emphasizing the State’s position with respect to Cone’s
alleged addiction, the prosecutor told the jury during closing
argument, “[Y]ou’re not dealing with a crazy person, an in
sane man. A man . . . out of his mind. You’re dealing,
I submit to you, with a premeditated, cool, deliberate—and
even cowardly, really—murderer.” Tr. 2084 (Apr. 22, 1982).
Pointing to the quantity of drugs found in Cone’s car, the
prosecutor suggested that far from being a drug addict, Cone
was actually a drug dealer. The prosecutor argued, “I’m not
trying to be absurd, but he says he’s a drug addict. I say
2 The State also cast doubt on Cone’s defense by eliciting testimony that
Cone had enrolled in college following his return from Vietnam and had
graduated with high honors. Later, after serving time in prison for an
armed robbery, Cone gained admission to the University of Arkansas Law
School. The State suggested that Cone’s academic success provided fur
ther proof that he was not impaired following his return from war.

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balony. He’s a drug seller. Doesn’t the proof show that?”
App. 107.3
The jury rejected Cone’s insanity defense and found him
guilty on all counts. At the penalty hearing, the prosecution
asked the jury to find that Cone’s crime met the criteria for
four different statutory aggravating factors, any one of
which would render him eligible for a capital sentence.4
Cone’s counsel called no witnesses but instead rested on the
evidence adduced during the guilt phase proceedings. Ac
knowledging that the prosecution’s experts had disputed the
existence of Cone’s alleged mental disorder, counsel never
theless urged the jury to consider Cone’s drug addiction
when weighing the aggravating and mitigating factors in the
case.5 The jury found all four aggravating factors and unan
imously returned a sentence of death.6
3 In his closing rebuttal argument, the prosecutor continued to press the
point, asserting: “There aren’t any charges for drug sales, but that doesn’t
mean that you can’t look and question in deciding whether or not this man
was, in fact, a drug user, or why he had those drugs. Did he just have
those drugs, or did he have those drugs and thousands of dollars in that
car? Among those drugs are there only the drugs he used? How do we
know if he used drugs? The only thing that we ever had that he used
drugs, period, is the fact that those drugs were in the car and what he
told people. What he told people. But according to even what he told
people, there are drugs in there he didn’t even use.” Tr. 2068 (Apr. 22,
1982).
4 The jury could impose a capital sentence only if it unanimously deter
mined that one or more statutory aggravating circumstances had been
proved by the State beyond a reasonable doubt, and that the mitigating
circumstances of the case did not outweigh any statutory aggravating fac
tors. Tenn. Code Ann. § 39–2–203(g) (1982).
5 As defense counsel emphasized to the jury, one of the statutory miti
gating factors it was required to consider was whether “[t]he capacity of
the defendant to appreciate the wrongfulness of his conduct or to conform
his conduct to the requirements of the law was substantially impaired as
a result of mental disease or defect or intoxication which was insufficient
to establish a defense to the crime but which substantially affected his
judgment.” § 39–2–203( j)(8).
6 Specifically, the jury found Cone had committed one or more prior fel
onies involving the use or threat of violence, see § 39–2–203(i)(2); the mur

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II
On direct appeal Cone raised numerous challenges to his
conviction and sentence. Among those was a claim that the
prosecution violated state law by failing to disclose a tape
recorded statement and police reports relating to several
trial witnesses. See id., at 114–117. The Tennessee Su
preme Court rejected each of Cone’s claims, and affirmed his
conviction and sentence. State v. Cone, 665 S. W. 2d 87
(1984).7 Cone then filed a petition for postconviction relief,
primarily raising claims that his trial counsel had been inef
fective; the Tennessee Court of Criminal Appeals affirmed
the denial of that petition in 1987. Cone v. State, 747 S. W.
2d 353.
In 1989, Cone, acting pro se, filed a second petition for
postconviction relief, raising myriad claims of error. Among
these was a claim that the State had failed to disclose evi
dence in violation of his rights under the United States Con
ders had been committed for the purpose of avoiding, interfering with, or
preventing Cone’s lawful arrest or prosecution, see § 39–2–203(i)(6); the
murders were especially heinous, atrocious, or cruel in that they involved
torture and depravity of mind, see § 39–2–203(i)(5); and Cone had know
ingly created a risk of death to two or more persons, other than the victim
murdered, during his act of murder, see § 39–2–203(i)(3). The Tennessee
Supreme Court later observed that by finding Cone guilty of murder in
the first degree during the perpetration of a burglary, the jury implicitly
found the existence of an additional statutory aggravating factor: that the
murders occurred while Cone was committing a burglary, § 39–2–203(i)(7).
State v. Cone, 665 S. W. 2d 87, 94 (1984).
7 In summarizing the trial proceedings the Tennessee Supreme Court
observed: “The only defense interposed on [Cone’s] behalf was that of in
sanity, or lack of mental capacity, due to drug abuse and to stress arising
out of his previous service in the Vietnamese war, some eleven years prior
to the events involved in this case. This proved to be a tenuous defense,
at best, since neither of the expert witnesses who testified on his behalf
had ever seen or heard of him until a few weeks prior to the trial. Nei
ther was a medical doctor or psychiatrist, and neither had purported to
treat him as a patient. Their testimony that he lacked mental capacity
was based purely upon his personal recitation to them of his history of
military service and drug abuse.” Id., at 90.

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stitution. At the State’s behest, the postconviction court
summarily denied the petition, concluding that all the claims
raised in it had either been “previously determined” or
“waived.” Order Dismissing Petition for Post-Conviction
Relief in Cone v. State, No. P–06874 (Crim. Ct. Shelby Cty.,
Tenn., Jan. 2, 1990).8 At that time, the court did not specify
which claims fell into which category.
Cone appealed the denial of his petition to the Tennessee
Court of Criminal Appeals, asserting that the postconviction
court had erred by dismissing 13 claims—his Brady claim
among them—as previously determined when, in fact, they
had not been “previously addressed or determined by any
court.” Brief for Petitioner-Appellant in No. P–06874,
pp. 23–24, and n. 11. In addition Cone urged the court to
remand the case to allow him, with the assistance of counsel,
to rebut the presumption that he had waived any of his
claims by not raising them at an earlier stage in the litiga
tion. Id., at 24.9 The court agreed and remanded the case
for further proceedings.
On remand counsel was appointed, and an amended peti
tion was filed. The State once again urged the postconvic
8 Under Tennessee law in effect at the time, a criminal defendant was
entitled to collateral relief if his conviction or sentence violated “any right
guaranteed by the constitution of [Tennessee] or the Constitution of the
United States.” Tenn. Code Ann. § 40–30–105 (1982); see also § 40–30–
102. Any hearing on a petition for postconviction relief was limited, how
ever, to claims that had not been “waived or previously determined.” See
§ 40–30–111. A ground for relief was “previously determined” if “a court
of competent jurisdiction ha[d] ruled on the merits [of the claim] after
a full and fair hearing.” § 40–30–112(a). The claim was waived “if the
petitioner knowingly and understandingly failed to present it for determi
nation in any proceeding before a court of competent jurisdiction in which
the ground could have been presented.” § 40–30–112(b)(1).
9 See Swanson v. State, 749 S. W. 2d 731, 734 (Tenn. 1988) (courts should
not dismiss postconviction petitions on technical grounds unless the pe
titioner has first had “reasonable opportunity, with aid of counsel, to
file amendments” and rebut presumption of waiver (internal quotation
marks omitted)).

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tion court to dismiss Cone’s petition. Apparently conflating
the state-law disclosure claim Cone had raised on direct ap
peal with his newly filed Brady claim, the State represented
that the Tennessee Supreme Court had already decided the
Brady issue and that Cone was therefore barred from reliti
gating it. See App. 15–16.
While that petition remained pending before the postcon
viction court, the Tennessee Court of Appeals held for the
first time that the State’s Public Records Act allowed a crim
inal defendant to review the prosecutor’s file in his case.
See Capital Case Resource Center of Tenn., Inc. v. Woodall,
No. 01–A–019104CH00150, 1992 WL 12217 (Jan. 29, 1992).
Based on that holding, Cone obtained access to the prosecu
tor’s files, in which he found proof that evidence had indeed
been withheld from him at trial. Among the undisclosed
documents Cone discovered were statements from witnesses
who had seen him several days before and several days after
the murders. The witnesses described Cone’s appearance
as “wild eyed,” App. 50, and his behavior as “real weird,”
id., at 49. One witness affirmed that Cone had appeared “to
be drunk or high.” Ibid. The file also contained a police
report describing Cone’s arrest in Florida following the mur
ders. In that report, a police officer described Cone looking
around “in a frenzied manner,” and “walking in [an] agitated
manner” prior to his apprehension. Id., at 53. Multiple po
lice bulletins describing Cone as a “drug user” and a “heavy
drug user” were also among the undisclosed evidence. See
id., at 55–59.
With the newly discovered evidence in hand, Cone
amended his postconviction petition once again in October
1993, expanding his Brady claim to allege more specifically
that the State had withheld exculpatory evidence demon
strating that he “did in fact suffer drug problems and/or drug
withdrawal or psychosis both at the time of the offense and
in the past.” App. 20. Cone pointed to specific examples
of evidence that had been withheld, alleging the evidence

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was “exculpatory to both the jury’s determination of peti
tioner’s guilt and its consideration of the proper sentence,”
and that there was “a reasonable probability that, had the
evidence not been withheld, the jurors would not have con
victed [him] and would not have sentenced him to death.”
Id., at 20–21.10 In a lengthy affidavit submitted with his
amended petition, Cone explained that he had not raised his
Brady claim in earlier proceedings because the facts under
lying it “ha[d] been revealed through disclosure of the State’s
files, which occurred after the first post-conviction proceed
ing.” App. 18.
After denying Cone’s request for an evidentiary hearing,
the postconviction court denied relief on each claim pre
sented in the amended petition. Many of the claims were
dismissed on the ground that they had been waived by
Cone’s failure to raise them in earlier proceedings; however,
consistent with the position urged by the State, the court
dismissed many others, including the Brady claim, as mere
“re-statements of previous grounds heretofore determined
and denied by the Tennessee Supreme Court upon Direct
Appeal or the Court of Criminal Appeals upon the First Peti
tion.” App. 22.
Noting that “the findings of the trial court in post
conviction hearings are conclusive on appeal unless the evi
dence preponderates against the judgment,” the Tennessee
Court of Criminal Appeals affirmed. Cone v. State, 927
S. W. 2d 579, 581–582 (1995). The court concluded that Cone
had “failed to rebut the presumption of waiver as to all
claims raised in his second petition for post-conviction relief
which had not been previously determined.” Id., at 582
(emphasis added). Cone unsuccessfully petitioned for re
10 As examples of evidence that had been withheld, Cone pointed to
“statements of Charles and Debbie Slaughter, statements of Sue Cone,
statements of Lucille Tuech, statements of Herschel Dalton, and pa
trolman Collins” and “statements contained in official police reports.”
App. 20.

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view in the Tennessee Supreme Court, and we denied certio
rari. Cone v. Tennessee, 519 U. S. 934 (1996).
III
In 1997, Cone filed a petition for a federal writ of habeas
corpus. Without disclosing to the District Court the con
trary position it had taken in the state-court proceedings,
the State acknowledged that Cone’s Brady claim had not
been raised prior to the filing of his second postconviction
petition. However, wrenching out of context the state ap
pellate court’s holding that Cone had “waived ‘all claims . . .
which had not been previously determined,’ ” the State now
asserted the Brady claim had been waived. App. 39 (quot
ing Cone, 927 S. W. 2d, at 582).
In May 1998, the District Court denied Cone’s request for
an evidentiary hearing on his Brady claim. Lamenting that
its consideration of Cone’s claims had been “made more diffi
cult” by the parties’ failure to articulate the state procedural
rules under which each of Cone’s claims had allegedly been
defaulted, App. to Pet. for Cert. 98a, the District Court nev
ertheless held that the Brady claim was procedurally barred.
After parsing the claim into 11 separate subclaims based on
11 pieces of withheld evidence identified in the habeas peti
tion, the District Court concluded that Cone had waived each
subclaim by failing to present or adequately develop it in
state court. App. to Pet. for Cert. 112a–113a. Moreover,
the court concluded that even if Cone had not defaulted his
Brady claim, it would fail on its merits because none of the
withheld evidence would have cast doubt on Cone’s guilt.
App. to Pet. for Cert. 116a–119a. Throughout its opinion
the District Court repeatedly referenced factual allegations
contained in early versions of Cone’s second petition for post
conviction relief rather than the amended version of the peti
tion upon which the state court’s decision had rested. See,
e. g., id., at 112a.

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After the District Court dismissed the remainder of Cone’s
federal claims, the Court of Appeals for the Sixth Circuit
granted him permission to appeal several issues, including
the alleged suppression of Brady material. Before the
Court of Appeals, the State shifted its procedural default
argument once more, this time contending that Cone had
“simply never raised” his Brady claim in the state court be
cause he failed to make adequate factual allegations to sup
port that claim in his second petition for postconviction
relief. App. 41. Repeating the District Court’s error, the
State directed the Court of Appeals’ attention to Cone’s
pro se petition and to the petition Cone’s counsel filed before
he gained access to the prosecution’s case file. Id., at 41–42,
and n. 7. In other words, instead of citing the October 1993
amended petition on which the state court’s decision had
been based and to which its order explicitly referred, the
State pointed the court to earlier, less developed versions of
the same claim.
The Court of Appeals concluded that Cone had procedur
ally defaulted his Brady claim and had failed to show cause
and prejudice to overcome the default. Cone v. Bell, 243
F. 3d 961, 968 (2001). The court acknowledged that Cone
had raised his Brady claim. 243 F. 3d, at 969. Neverthe
less, the court considered itself barred from reaching the
merits of the claim because the Tennessee courts had con
cluded the claim was “previously determined or waived
under Tenn. Code Ann. § 40–30–112.” Ibid.
Briefly mentioning several isolated pieces of suppressed
evidence, the court summarily concluded that even if Cone’s
Brady claim had not been defaulted, the suppressed evidence
would not undermine confidence in the verdict (and hence
was not Brady material) “because of the overwhelming evi
dence of Cone’s guilt.” 243 F. 3d, at 968, 969. The court
did not discuss whether any of the undisclosed evidence was
material with respect to Cone’s sentencing proceedings.

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Although the Court of Appeals rejected Cone’s Brady
claim, it held that he was entitled to have his death sentence
vacated because of his counsel’s ineffective assistance at sen
tencing. See 243 F. 3d, at 975. In 2002, this Court reversed
that holding after concluding that the Tennessee courts’ re
jection of Cone’s ineffective-assistance-of-counsel claim was
not “objectively unreasonable” within the meaning of the
Antiterrorism and Effective Death Penalty Act of 1996
(AEDPA). See Bell v. Cone, 535 U. S. 685, 699.
In 2004, following our remand, the Court of Appeals again
entered judgment ordering a new sentencing hearing, this
time based on the purported invalidity of an aggravating cir
cumstance found by the jury. Cone v. Bell, 359 F. 3d 785.
Again we granted certiorari and reversed, relying in part on
the deferential standard that governs our review of state
court decisions under AEDPA. See Bell v. Cone, 543 U. S.
447, 452–458 (2005) (per curiam).
Following our second remand, the Court of Appeals revis
ited Cone’s Brady claim. This time, the court divided the
claim into four separate subclaims: “(1) evidence regarding
[Cone’s] drug use; (2) evidence that might have been useful to
impeach the testimony and credibility of prosecution witness
Sergeant Ralph Roby; (3) FBI reports;[11] and (4) evidence
showing that prosecution witness Ilene Blankman was un
truthful and biased.” 492 F. 3d, at 753. Noting that it had
previously found all four subclaims to be procedurally de
faulted, the court declined to reconsider its earlier decision.
See ibid. (citing Cone, 243 F. 3d, at 968–970). At the same
time, the court reiterated that the withheld evidence “would
11 In the course of federal habeas proceedings, Cone had obtained access
to files from the Federal Bureau of Investigation where he found addi
tional previously undisclosed evidence not contained in the state prosecu
tor’s case file. The suppressed FBI documents make repeated reference
to Cone’s drug use and corroborate his expert’s representation that he
had used drugs during his prior incarceration for armed robbery. See
App. 26–28.

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not have overcome the overwhelming evidence of Cone’s
guilt in committing a brutal double murder and the persua
sive testimony that Cone was not under the influence of
drugs.” 492 F. 3d, at 756. Summarily discounting Cone’s
contention that the withheld evidence was material with re
spect to his sentence, the court concluded that the introduc
tion of the suppressed evidence would not have altered the
jurors’ finding that Cone’s alleged drug use did not “vitiate
his specific intent to murder his victims and did not mitigate
his culpability sufficient to avoid the death sentence.” Id.,
at 757.
Judge Merritt dissented. He castigated the State not
only for withholding documents relevant to Cone’s sole de
fense and plea for mitigation, but also for its “falsification of
the procedural record . . . concerning the State’s procedural
default defense to the Brady claim.” Id., at 760. Over the
dissent of seven judges, Cone’s petition for rehearing en banc
was denied. 505 F. 3d 610 (2007).
We granted certiorari to answer the question whether a
federal habeas claim is “ ‘procedurally defaulted’ ” when it is
twice presented to the state courts. Pet. for Cert. i.
IV
During the state and federal proceedings below, the State
of Tennessee offered two different justifications for denying
review of the merits of Cone’s Brady claim. First, in con
nection with Cone’s amended petition for state postconvic
tion relief, the State argued that the Brady claim was barred
because it had been decided on direct appeal. See App. 15–
16. Then, in connection with Cone’s federal habeas petition,
the State argued that Cone’s claim was waived because it
had never been properly raised before the state courts. See
id., at 39. The District Court and the Court of Appeals
agreed that Cone’s claim was procedurally barred, but for
different reasons. The District Court held that the claim

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had been waived, App. to Pet. for Cert. 102a, while the Court
of Appeals held that the claim had been either waived or
previously determined, Cone, 243 F. 3d, at 969. We now
conclude that neither prior determination nor waiver pro
vides an independent and adequate state ground for denying
Cone review of his federal claim.
It is well established that federal courts will not review
questions of federal law presented in a habeas petition when
the state court’s decision rests upon a state-law ground that
“is independent of the federal question and adequate to sup
port the judgment.” Coleman v. Thompson, 501 U. S. 722,
729 (1991); Lee v. Kemna, 534 U. S. 362, 375 (2002). In the
context of federal habeas proceedings, the independent and
adequate state ground doctrine is designed to “ensur[e] that
the States’ interest in correcting their own mistakes is re
spected in all federal habeas cases.” Coleman, 501 U. S., at
732. When a petitioner fails to properly raise his federal
claims in state court, he deprives the State of “an opportu
nity to address those claims in the first instance” and frus
trates the State’s ability to honor his constitutional rights.
Id., at 732, 748. Therefore, consistent with the longstanding
requirement that habeas petitioners must exhaust available
state remedies before seeking relief in federal court, we have
held that when a petitioner fails to raise his federal claims
in compliance with relevant state procedural rules, the state
court’s refusal to adjudicate the claim ordinarily qualifies as
an independent and adequate state ground for denying fed
eral review. See id., at 731.
That does not mean, however, that federal habeas review
is barred every time a state court invokes a procedural rule
to limit its review of a state prisoner’s claims. We have rec
ognized that “ ‘[t]he adequacy of state procedural bars to the
assertion of federal questions’ . . . is not within the State’s
prerogative finally to decide; rather, adequacy ‘is itself a fed
eral question.’ ” Lee, 534 U. S., at 375 (quoting Douglas v.

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Alabama, 380 U. S. 415, 422 (1965)); see also Coleman, 501
U. S., at 736 (“[F]ederal habeas courts must ascertain for
themselves if the petitioner is in custody pursuant to a state
court judgment that rests on independent and adequate state
grounds”). The question before us now is whether federal
review of Cone’s Brady claim is procedurally barred either
because the claim was twice presented to the state courts or
because it was waived, and thus not presented at all.
First, we address the contention that the repeated presen
tation of a claim in state court bars later federal review.
The Tennessee postconviction court denied Cone’s Brady
claim after concluding it had been previously determined fol
lowing a full and fair hearing in state court. See Tenn. Code
Ann. § 40–30–112(a). That conclusion rested on a false
premise: Contrary to the state courts’ finding, Cone had not
presented his Brady claim in earlier proceedings, and, conse
quently, the state courts had not passed on it. The Sixth
Circuit recognized that Cone’s Brady claim had not been de
cided on direct appeal, see Cone, 243 F. 3d, at 969, but felt
constrained by the state courts’ refusal to reach the merits of
that claim on postconviction review. The Court of Appeals
concluded that because the state postconviction courts had
applied a state procedural law to avoid reaching the merits
of Cone’s Brady claim, “an ‘independent and adequate’ state
ground” barred federal habeas review. 243 F. 3d, at 969.
In this Court the State does not defend that aspect of the
Court of Appeals’ holding, and rightly so.
When a state court declines to review the merits of a peti
tioner’s claim on the ground that it has done so already, it
creates no bar to federal habeas review. In Ylst v. Nunnem
aker, 501 U. S. 797, 804, n. 3 (1991), we observed in passing
that when a state court declines to revisit a claim it has al
ready adjudicated, the effect of the later decision upon the
availability of federal habeas is “nil” because “a later state
decision based upon ineligibility for further state review nei
ther rests upon procedural default nor lifts a pre-existing

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procedural default.” 12 When a state court refuses to read
judicate a claim on the ground that it has been previously
determined, the court’s decision does not indicate that the
claim has been procedurally defaulted. To the contrary, it
provides strong evidence that the claim has already been
given full consideration by the state courts and thus is ripe
for federal adjudication. See 28 U. S. C. § 2254(b)(1)(A) (per
mitting issuance of a writ of habeas corpus only after “the
applicant has exhausted the remedies available in the courts
of the State”).
A claim is procedurally barred when it has not been fairly
presented to the state courts for their initial consideration—
not when the claim has been presented more than once. Ac
cordingly, insofar as the Court of Appeals rejected Cone’s
Brady claim as procedurally defaulted because the claim had
been twice presented to the Tennessee courts, its decision
was erroneous.
As an alternative (and contradictory) ground for barring
review of Cone’s Brady claim, the State has argued that
Cone’s claim was properly dismissed by the state postconvic
tion court on the ground it had been waived. We are not
persuaded. The state appellate court affirmed the denial of
Cone’s Brady claim on the same mistaken ground offered by
the lower court—that the claim had been previously deter
mined.13 Contrary to the State’s assertion, the Tennessee
12 With the exception of the Sixth Circuit, all Courts of Appeals to have
directly confronted the question both before and after Ylst, 501 U. S. 797,
have agreed that a state court’s successive rejection of a federal claim
does not bar federal habeas review. See, e. g., Page v. Frank, 343 F. 3d
901, 907 (CA7 2003); Brecheen v. Reynolds, 41 F. 3d 1343, 1358 (CA10
1994); Bennett v. Whitley, 41 F. 3d 1581, 1582 (CA5 1994); Silverstein v.
Henderson, 706 F. 2d 361, 368 (CA2 1983). See also Lambright v. Stewart,
241 F. 3d 1201, 1206 (CA9 2001).
13 As recounted earlier, Cone’s state postconviction petition contained
numerous claims of error. The state postconviction court dismissed some
of those claims as waived and others, including the Brady claim, as having
been previously determined. In affirming the denial of Cone’s petition

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appellate court did not hold that Cone’s Brady claim was
waived.
When a state court declines to find that a claim has been
waived by a petitioner’s alleged failure to comply with state
procedural rules, our respect for the state-court judgment
counsels us to do the same. Although we have an independ
ent duty to scrutinize the application of state rules that bar
our review of federal claims, Lee, 534 U. S., at 375, we have
no concomitant duty to apply state procedural bars where
the Tennessee Court of Criminal Appeals summarily stated that Cone had
“failed to rebut the presumption of waiver as to all claims raised in his
second petition for post-conviction relief which had not been previously
determined.” Cone v. State, 927 S. W. 2d 579, 582 (1995). Pointing to
that language, the State asserts that the Tennessee Court of Criminal
Appeals denied Cone’s Brady claim not because it had been previously
determined, but because it was waived in the postconviction court pro
ceedings. Not so. Without questioning the trial court’s finding that
Cone’s Brady claim had been previously determined, the Court of Crimi
nal Appeals affirmed the denial of Cone’s postconviction petition in its
entirety. Nothing in that decision suggests the appellate court believed
the Brady claim had been waived in the court below.
Similarly, while Justice Alito’s parsing of the record persuades him
that Cone failed to adequately raise his Brady claim to the Tennessee
Court of Criminal Appeals, he does not argue that the court expressly
held that Cone waived the claim. A review of Cone’s opening brief
reveals that he made a broad challenge to the postconviction court’s
dismissal of his petition and plainly asserted that the court erred by
dismissing claims as previously determined on direct appeal or in his
initial postconviction petition. See Brief for Petitioner-Appellant in
No. 02–C–01–9403–CR–00052 (Tenn. Crim. App.), pp. 7, 14. The state
appellate court did not state or suggest that Cone had waived his Brady
claim. Rather, after commending the postconviction court for its “exem
plary and meticulous treatment of the appellant’s petition,” Cone, 927 S. W.
2d, at 581, the appellate court simply adopted without modification the
lower court’s findings with respect to the application of Tenn. Code Ann.
§ 40–30–112 to the facts of this case. The best reading of the Tennessee
Court of Criminal Appeals’ decision is that it was based on an approval
of the postconviction court’s reasoning rather than on an unmentioned fail
ure by Cone to adequately challenge the dismissal of his Brady claim on
appeal.

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state courts have themselves declined to do so. The Tennes
see courts did not hold that Cone waived his Brady claim,
and we will not second-guess their judgment.14
The State’s procedural objections to federal review of the
merits of Cone’s claim have resulted in a significant delay
in bringing this unusually protracted case to a conclusion.
Ultimately, however, they provide no obstacle to judicial re
view. Cone properly preserved and exhausted his Brady
claim in the state court; therefore, it is not defaulted. We
turn now to the merits of that claim.
V
Although the State is obliged to “prosecute with earnest
ness and vigor,” it “is as much [its] duty to refrain from im
proper methods calculated to produce a wrongful conviction
as it is to use every legitimate means to bring about a just
one.” Berger, 295 U. S., at 88. Accordingly, we have held
that when the State withholds from a criminal defendant evi
dence that is material to his guilt or punishment, it violates
his right to due process of law in violation of the Fourteenth
Amendment. See Brady, 373 U. S., at 87. In United States
v. Bagley, 473 U. S. 667, 682 (1985) (opinion of Blackmun, J.),
we explained that evidence is “material” within the meaning
14 Setting aside the state courts’ mistaken belief that Cone’s Brady claim
had been previously determined, there are many reasons the state courts
might have rejected the State’s waiver argument. The record establishes
that the suppressed documents which form the basis for Cone’s claim were
not available to him until the Tennessee Court of Appeals’ 1992 decision
interpreting the State’s Public Records Act as authorizing the disclosure
of prosecutorial records. Soon after obtaining access to the prosecutor’s
file and discovering within it documents that had not been disclosed prior
to trial, Cone amended his petition for postconviction relief, adding de
tailed allegations regarding the suppressed evidence recovered from the
file, along with an affidavit explaining the reason why his claim had not
been filed sooner. See App. 13, 18. The State did not oppose the amend
ment of Cone’s petition on the ground that it was untimely, and it appears
undisputed that there would have been no basis under state law for doing
so. See Brief for Petitioner 7, n. 1.

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of Brady when there is a reasonable probability that, had the
evidence been disclosed, the result of the proceeding would
have been different. In other words, favorable evidence is
subject to constitutionally mandated disclosure when it
“could reasonably be taken to put the whole case in such a
different light as to undermine confidence in the verdict.”
Kyles v. Whitley, 514 U. S. 419, 435 (1995); accord, Banks v.
Dretke, 540 U. S. 668, 698–699 (2004); Strickler v. Greene, 527
U. S. 263, 290 (1999).15
The documents suppressed by the State vary in kind, but
they share a common feature: Each strengthens the infer
ence that Cone was impaired by his use of drugs around the
time his crimes were committed. The suppressed evidence
includes statements by witnesses acknowledging that Cone
appeared to be “drunk or high,” App. 49, “acted real weird,”
ibid., and “looked wild eyed,” id., at 50, in the two days pre
ceding the murders.16 It also includes documents that could
15 Although the Due Process Clause of the Fourteenth Amendment, as
interpreted by Brady, only mandates the disclosure of material evidence,
the obligation to disclose evidence favorable to the defense may arise more
broadly under a prosecutor’s ethical or statutory obligations. See Kyles,
514 U. S., at 437 (“[T]he rule in Bagley (and, hence, in Brady) requires less
of the prosecution than the ABA Standards for Criminal Justice . . . . See
. . . Prosecution Function and Defense Function 3–3.11(a) (3d ed. 1993)”).
See also ABA Model Rule of Professional Conduct 3.8(d) (2008) (“The
prosecutor in a criminal case shall” “make timely disclosure to the defense
of all evidence or information known to the prosecutor that tends to negate
the guilt of the accused or mitigates the offense, and, in connection with
sentencing, disclose to the defense and to the tribunal all unprivileged
mitigating information known to the prosecutor, except when the prosecu
tor is relieved of this responsibility by a protective order of the tribunal”).
As we have often observed, the prudent prosecutor will err on the side of
transparency, resolving doubtful questions in favor of disclosure. See
Kyles, 514 U. S., at 439; United States v. Bagley, 473 U. S. 667, 711, n. 4
(1985) (Stevens, J., dissenting); United States v. Agurs, 427 U. S. 97, 108
(1976).
16 The State contends that the statements were made by witnesses who
observed Cone during and immediately after he committed robberies;
therefore, it is not surprising that Cone appeared less than “serene.” See

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have been used to impeach witnesses whose trial testimony
cast doubt on Cone’s drug addiction. For example, Memphis
police officer Ralph Roby testified at trial that Cone had no
needle marks on his body when he was arrested—an obser
vation that bolstered the State’s argument that Cone was
not a drug user. The suppressed evidence reveals, however,
that Roby authorized multiple teletypes to law enforcement
agencies in the days following the murders in which he de
scribed Cone as a “drug user” and a “heavy drug user.” See
id., at 55–58.17 A suppressed statement made by the chief
of police of Cone’s hometown also describes Cone as a serious
drug user. See Cone, 243 F. 3d, at 968. And undisclosed
notes of a police interview with Ilene Blankman conducted
several days after the murders reveal discrepancies between
her initial statement and her trial testimony relevant to
Cone’s alleged drug use. App. 72–73. In sum, both the
quantity and the quality of the suppressed evidence lends
support to Cone’s position at trial that he habitually used
excessive amounts of drugs, that his addiction affected his
behavior during his crime spree, and that the State’s argu
ments to the contrary were false and misleading.
Brief for Respondent 46. Although a jury would have been free to infer
that Cone’s behavior was attributable to his criminal activity, the evidence
is also consistent with Cone’s assertion that he was suffering from chronic
amphetamine psychosis at the time of the crimes.
17 As the dissent points out, Roby did not testify directly that Cone was
not a drug user, and FBI Agent Eugene Flynn testified that, at the time of
Cone’s arrest in Pompano Beach, Cone reported that he had used cocaine,
Dilaudid, and Demerol and was suffering from “ ‘slight withdrawal symp
toms.’ ” See post, at 492–493, 496 (opinion of Thomas, J.). See also
Tr. 1916, 1920 (Apr. 22, 1982). It is important to note, however, that nei
ther Flynn nor Roby corroborated Cone’s account of alleged drug use.
Taken in context, Roby’s statement that he had not observed any needle
marks on Cone’s body invited the jury to infer that Cone’s self-reported
drug use was either minimal or contrived. See id., at 1939. Therefore,
although the suppressed evidence does not directly contradict Roby’s trial
testimony, it does place it in a different light.

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Thus, the federal question that must be decided is whether
the suppression of that probative evidence deprived Cone of
his right to a fair trial. See Agurs, 427 U. S., at 108. Be
cause the Tennessee courts did not reach the merits of Cone’s
Brady claim, federal habeas review is not subject to the def
erential standard that applies under AEDPA to “any claim
that was adjudicated on the merits in State court proceed
ings.” 28 U. S. C. § 2254(d). Instead, the claim is reviewed
de novo. See, e. g., Rompilla v. Beard, 545 U. S. 374, 390
(2005) (de novo review where state courts did not reach prej
udice prong under Strickland v. Washington, 466 U. S. 668
(1984)); Wiggins v. Smith, 539 U. S. 510, 534 (2003) (same).
Contending that the Federal District Court and Court of
Appeals adequately and correctly resolved the merits of that
claim, the State urges us to affirm the Sixth Circuit’s denial
of habeas relief. In assessing the materiality of the evi
dence suppressed by the State, the Court of Appeals sug
gested that two facts outweighed the potential force of the
suppressed evidence. First, the evidence of Cone’s guilt
was overwhelming. Second, the evidence of Cone’s drug use
was cumulative because the jury had heard evidence of
Cone’s alleged addiction from witnesses and from officers
who interviewed Cone and recovered drugs from his vehi
cle.18 The Court of Appeals did not thoroughly review the
suppressed evidence or consider what its cumulative effect
on the jury would have been. Moreover, in concluding that
the suppressed evidence was not material within the mean
ing of Brady, the court did not distinguish between the mate
riality of the evidence with respect to guilt and the material
ity of the evidence with respect to punishment—an omission
we find significant.
18 In pointing to the trial evidence of Cone’s drug use, the Court of Ap
peals made no mention of the fact that the State had discredited the testi
mony of Cone’s experts on the ground that no independent evidence cor
roborated Cone’s alleged addiction and that the State had argued that the
drugs in Cone’s car were intended for resale, rather than personal use.

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Evidence that is material to guilt will often be material
for sentencing purposes as well; the converse is not always
true, however, as Brady itself demonstrates. In our seminal
case on the disclosure of prosecutorial evidence, defendant
John Brady was indicted for robbery and capital murder.
At trial, Brady took the stand and confessed to robbing the
victim and being present at the murder but testified that his
accomplice had actually strangled the victim. Brady v.
State, 226 Md. 422, 425, 174 A. 2d 167, 168 (1961). After
Brady was convicted and sentenced to death he discovered
that the State had suppressed the confession of his accom
plice, which included incriminating statements consistent
with Brady’s version of events. Id., at 426, 174 A. 2d, at
169. The Maryland Court of Appeals concluded that Brady’s
due process rights were violated by the suppression of the
accomplice’s confession but declined to order a new trial on
guilt. Observing that nothing in the accomplice’s confession
“could have reduced . . . Brady’s offense below murder in the
first degree,” the state court ordered a new trial on the ques
tion of punishment only. Id., at 430, 174 A. 2d, at 171. We
granted certiorari and affirmed, rejecting Brady’s contention
that the state court’s limited remand violated his constitu
tional rights. 373 U. S., at 88.
As in Brady, the distinction between the materiality of the
suppressed evidence with respect to guilt and punishment is
significant in this case. During the guilt phase of Cone’s
trial, the only dispute was whether Cone was “sane under
the law,” Tr. 2040 (Apr. 22, 1982), as his counsel described
the issue, or “criminally responsible” for his conduct, App.
110, as the prosecutor argued. Under Tennessee law, Cone
could not be held criminally responsible for the murders if,
“at the time of [his] conduct as a result of mental disease or
defect he lack[ed] substantial capacity either to appreciate
the wrongfulness of his conduct or to conform his conduct to
the requirements of law.” Graham v. State, 547 S. W. 2d
531, 543 (Tenn. 1977). Although we take exception to the

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Court of Appeals’ failure to assess the effect of the sup
pressed evidence “collectively” rather than “item by item,”
see Kyles, 514 U. S., at 436, we nevertheless agree that even
when viewed in the light most favorable to Cone, the evi
dence falls short of being sufficient to sustain his insanity
defense.
Cone’s experts testified that his drug addiction and post
traumatic stress disorder originated during his service in
Vietnam, more than 13 years before the Todds were mur
dered. During those years, despite Cone’s drug use and
mental disorder, he managed to successfully complete his ed
ucation, travel, and (when not incarcerated) function in civil
society. The suppressed evidence may have strengthened
the inference that Cone was on drugs or suffering from with
drawal at the time of the murders, but his behavior before,
during, and after the crimes was inconsistent with the con
tention that he lacked substantial capacity either to appreci
ate the wrongfulness of his conduct or to conform his conduct
to the requirements of law. See Graham, 547 S. W. 2d, at
543. The likelihood that the suppressed evidence would
have affected the jury’s verdict on the issue of insanity is
therefore remote. Accordingly, we conclude that the Sixth
Circuit did not err by denying habeas relief on the ground
that the suppressed evidence was immaterial to the jury’s
finding of guilt.
The same cannot be said of the Court of Appeals’ summary
treatment of Cone’s claim that the suppressed evidence in
fluenced the jury’s sentencing recommendation. There is a
critical difference between the high standard Cone was re
quired to satisfy to establish insanity as a matter of Tennes
see law and the far lesser standard that a defendant must
satisfy to qualify evidence as mitigating in a penalty hearing
in a capital case. See Bell, 535 U. S., at 712 (Stevens, J.,
dissenting) (“[T]here is a vast difference between insanity—
which the defense utterly failed to prove—and the possible
mitigating effect of drug addiction incurred as a result of

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honorable service in the military”). As defense counsel em
phasized in his brief opening statement during penalty phase
proceedings, the jury was statutorily required to consider
whether Cone’s “capacity . . . to appreciate the wrongfulness
of his conduct or to conform his conduct to the requirements
of the law was substantially impaired as a result of mental
disease or defect or intoxication which was insufficient to
establish a defense to the crime but which substantially af
fected his judgment.” Tenn. Code Ann. § 39–2–203( j)(8).
It is possible that the suppressed evidence, viewed cumula
tively, may have persuaded the jury that Cone had a far more
serious drug problem than the prosecution was prepared to
acknowledge, and that Cone’s drug use played a mitigating,
though not exculpating, role in the crimes he committed.19
The evidence might also have rebutted the State’s sugges
tion that Cone had manipulated his expert witnesses into
falsely believing he was a drug addict when in fact he did
not struggle with substance abuse.
Neither the Court of Appeals nor the District Court fully
considered whether the suppressed evidence might have
persuaded one or more jurors that Cone’s drug addiction—
especially if attributable to honorable service of his country
in Vietnam—was sufficiently serious to justify a decision to
imprison him for life rather than sentence him to death.
Because the evidence suppressed at Cone’s trial may well
have been material to the jury’s assessment of the proper
punishment in this case, we conclude that a full review of
the suppressed evidence and its effect is warranted.
19 We agree with the dissent that the standard to be applied by the
District Court in evaluating the merits of Cone’s Brady claim on remand
is whether there is a reasonable probability that, had the suppressed evi
dence been disclosed, the result of the proceeding would have been differ
ent. See post, at 491. Because neither the District Court nor the Court
of Appeals considered the merits of Cone’s claim with respect to the effect
of the withheld evidence on his sentence, it is appropriate for the District
Court, rather than this Court, to do so in the first instance.

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476 CONE v. BELL
Roberts, C. J., concurring in judgment
VI
In the 27 years since Gary Cone was convicted of murder
and sentenced to death, no Tennessee court has reached the
merits of his claim that state prosecutors withheld evidence
that would have bolstered his defense and rebutted the
State’s attempts to cast doubt on his alleged drug addiction.
Today we hold that the Tennessee courts’ procedural rejec
tion of Cone’s Brady claim does not bar federal habeas re
view of the merits of that claim. Although we conclude that
the suppressed evidence was not material to Cone’s convic
tion for first-degree murder, the lower courts erred in failing
to assess the cumulative effect of the suppressed evidence
with respect to Cone’s capital sentence. Accordingly, the
judgment of the Court of Appeals is vacated, and the case is
remanded to the District Court with instructions to give full
consideration to the merits of Cone’s Brady claim.
It is so ordered.
Chief Justice Roberts, concurring in the judgment.
The Court’s decision is grounded in unusual facts that nec
essarily limit its reach. When issues under Brady v. Mary
land, 373 U. S. 83 (1963), are presented on federal habeas,
they usually have been previously addressed in state pro
ceedings. Federal review is accordingly sharply limited by
established principles of deference: If the claim has been
waived under state rules, that waiver typically precludes
federal review. If the claim has been decided in the state
system, federal review is restricted in light of the state
court’s legal and factual conclusions. The unique procedural
posture of this case presents a Brady claim neither barred
under state rules for failure to raise it nor decided in the
state system.
When it comes to that claim, the Court specifies that the
appropriate legal standard is the one we set forth in Kyles

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Roberts, C. J., concurring in judgment
v. Whitley, 514 U. S. 419, 435 (1995) (whether “the favorable
evidence could reasonably be taken to put the whole case in
such a different light as to undermine confidence in the ver
dict”). See ante, at 470, 475, n. 19. I do not understand
the majority to depart from that standard, and the majority
certainly does not purport to do so.
That leaves only application of the accepted legal standard
to the particular facts. It is highly unusual for this Court
to engage in such an enterprise, see Kyles, supra, at 458
(Scalia, J., dissenting), and the Court’s asserted basis for
doing so in this case is dubious, see post, at 486, 489–490
(Thomas, J., dissenting).
In any event, the Court’s review of the facts does not lead
it to conclude that Cone is entitled to relief—only that the
courts below did not adequately consider his claim with re
spect to sentencing. See ante, at 475 (“Neither the Court of
Appeals nor the District Court fully considered whether the
suppressed evidence” undermines confidence in Cone’s sen
tence). The Court simply reviews the facts in the light most
favorable to Cone, concludes that the evidence does not un
dermine confidence in the jury’s determination that Cone is
guilty, but sends the case back for “full consideration” of
whether the same is true as to the jury’s sentence of death.
Ante, at 474–476.
So this is what we are left with: a fact-specific determina
tion, under the established legal standard, viewing the
unique facts in favor of the defendant, that the Brady claim
fails with respect to guilt, but might have merit as to sen
tencing. In light of all this, I see no reason to quarrel with
the Court’s ruling on the Brady claim.
In considering on remand whether the facts establish a
Brady violation, it is clear that the lower courts should ana
lyze the issue under the constitutional standards we have
set forth, not under whatever standards the American Bar
Association may have established. The ABA standards are

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478 CONE v. BELL
Opinion of Alito, J.
wholly irrelevant to the disposition of this case, and the ma
jority’s passing citation of them should not be taken to sug
gest otherwise. See ante, at 470, n. 15.
Justice Alito, concurring in part and dissenting in part.
We granted certiorari in this case to answer two questions:
“1. Is a federal habeas claim ‘procedurally defaulted’
because it has been presented twice to the state courts?
“2. Is a federal habeas court powerless to recognize
that a state court erred in holding that state law pre
cludes reviewing a claim?” Pet. for Cert. i.
Both of these questions are based on a factually incorrect
premise, namely, that the Tennessee Court of Criminal Ap
peals, the highest state court to entertain petitioner’s appeal
from the denial of his second petition for state postconviction
relief,1 rejected petitioner’s Brady 2 claim on the ground that
the claim had been previously decided by the Tennessee Su
preme Court in petitioner’s direct appeal. Petitioner’s ar
gument is that the State Supreme Court did not decide any
Brady issue on direct appeal, that the Tennessee Court of
Criminal Appeals erred in holding otherwise, and that the
Sixth Circuit erred in concluding that the Brady claim had
been procedurally defaulted on this ground. Petitioner is
quite correct that his Brady claim was not decided on direct
appeal, and the Court in the present case is clearly correct
in holding that a second attempt to litigate a claim in state
1 Because the Tennessee Supreme Court denied discretionary review of
the Tennessee Court of Criminal Appeals decision affirming the denial of
petitioner’s second amended petition for postconviction relief, we must
look to the decision of the latter court to determine if the decision below
was based on an adequate and independent state ground. See Baldwin
v. Reese, 541 U. S. 27, 30–32 (2004); O’Sullivan v. Boerckel, 526 U. S. 838,
842–843 (1999).
2 Brady v. Maryland, 373 U. S. 83 (1963).

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court does not necessarily bar subsequent federal habeas re
view. See ante, at 466–467.
But all of this is beside the point because the Tennessee
Court of Criminal Appeals did not reject petitioner’s Brady
claim on the ground that the claim had been previously de
termined on direct appeal. Rather, petitioner’s Brady claim
was simply never raised before the Tennessee Court of Crim
inal Appeals, and that court did not rule on the claim at all.
Because the Sixth Circuit’s decision on the issue of proce
dural default rests on the same mistaken premise that the
Tennessee Court of Criminal Appeals rejected petitioner’s
Brady claim on the ground that it had been previously deter
mined, I entirely agree with the majority that the Sixth Cir
cuit’s decision on that issue cannot be sustained and that a
remand is required. I cannot join the Court’s opinion, how
ever, for two chief reasons.
First, the Court states without explanation that “Cone
properly preserved and exhausted his Brady claim in the
state court” and that therefore the claim has not been de
faulted. Ante, at 469. Because Cone never fairly raised
this claim in the Tennessee Court of Criminal Appeals, the
claim is either not exhausted (if Cone could now raise the
claim in state court) or is procedurally defaulted (if state law
now provides no avenue for further review). I would leave
these questions for resolution in the first instance on remand.
Second, the Court, again without explanation, remands
this case to the District Court, not the Court of Appeals.
I see no justification for this step.
I
In order to understand the tangled procedural default
issue presented in this case, it is necessary to review the
far-from-exemplary manner in which the attorneys for peti
tioner and respondent litigated the Brady claim in the state
courts.

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480 CONE v. BELL
Opinion of Alito, J.
On direct appeal, petitioner did not raise any Brady claim.
As the Court notes, petitioner did claim that the State had
violated a state discovery rule by failing to provide prior
statements given by certain witnesses and that therefore
the testimony of these witnesses should have been stricken.
App. 114–117; State v. Cone, 665 S. W. 2d 87, 94 (Tenn. 1984).
Although this claim concerned the State’s failure to turn over
information, it is clear that this was not a Brady claim.
The first appearance of anything resembling the claim now
at issue occurred in 1993 when petitioner’s experienced at
torneys filed an amendment to his second petition for post
conviction relief in the Shelby County Criminal Court. This
petition included a long litany of tangled claims. Paragraph
35 of this amended petition claimed, among other things, that
the State had wrongfully withheld information demonstrat
ing that one particular prosecution witness had testified
falsely concerning “petitioner and his drug use.” App. 13–
14. This nondisclosure, the petition stated, violated not only
the Fifth and Fourteenth Amendments to the Constitution
of the United States (which protect the due process right on
which Brady is based) but also the Fourth, Sixth, and Eighth
Amendments to the United States Constitution and four pro
visions of the Tennessee Constitution.
Two months later, counsel for petitioner filed an amend
ment adding 12 more claims, including one (¶ 41) alleging
that the State had abridged petitioner’s rights by failing to
disclose evidence that petitioner suffered from drug prob
lems. App. 20. According to this new submission, the non
disclosure violated, in addition to the previously cited pro
visions of the Federal and State Constitutions, five more
provisions of the State Constitution, including provisions re
garding double jeopardy, see Tenn. Const., Art. I, § 10, ex
post facto laws, § 11, indictment, § 14, and open courts, § 17.
The Shelby County Criminal Court was faced with the
task of wading through the morass presented in the amended
petition. Under Tenn. Code Ann. § 40–30–112 (1990) (re

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481 Cite as: 556 U. S. 449 (2009)
Opinion of Alito, J.
pealed 1995),3 a claim could not be raised in a postconviction
proceeding if the claim had been “previously determined” or
waived. Citing the State Supreme Court’s rejection on di
rect appeal of petitioner’s claim that the prosecution had vio
lated a state discovery rule by failing to turn over witness
statements, the State incorrectly informed the court that the
failure-to-disclose-exculpatory-evidence claim set out in ¶ 41
had been “previously determined” on direct appeal. App.
15–16. The Shelby County Criminal Court rejected the
claim on this ground, and held that all of petitioner’s claims
had either been previously determined or waived. Id., at 22.
Given the importance now assigned to petitioner’s Brady
claim, one might think that petitioner’s attorneys would have
(1) stressed that claim in the opening brief that they filed in
the Tennessee Court of Criminal Appeals, (2) pointed out the
lower court’s clear error in concluding that this claim had
been decided in the direct appeal, and (3) explained that in
formation supporting the claim had only recently come to
light due to the production of documents under the State’s
Public Records Act. But counsel did none of these things.
In fact, the Brady claim was not mentioned at all.
Nor was Brady cited in the reply brief filed by the same
attorneys. The reply brief did contain a passing reference
to “the withholding of exculpatory evidence,” but the brief
did not elaborate on this claim and again failed to mention
that this claim had never been previously decided and was
supported by newly discovered evidence.4
3 Tennessee law has since changed. Currently, the Tennessee Post-
Conviction Procedure Act bars any second postconviction petition, see
Tenn. Code Ann. § 40–30–102 (2006), and permits the reopening of a peti
tion only under limited circumstances, § 40–30–117. These restrictions
apply to any petition filed after the enactment of the Post-Conviction Pro
cedure Act, even if the conviction occurred long before.
4 After referring to a long list of claims (not including any claim for the
failure to disclose exculpatory evidence), the reply brief states:
“[I]t is clear that meritorious claims have been presented for adjudication.
These claims have not been waived and a remand for a hearing is essential

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482 CONE v. BELL
Opinion of Alito, J.
The Tennessee Court of Criminal Appeals affirmed the de
cision of the lower state court, but the appellate court made
no mention of the Brady claim, and I see no basis for conclud
ing that the court regarded the issue as having been raised
on appeal.
Appellate courts generally do not reach out to decide is
sues not raised by the appellant. Snell v. Tunnell, 920 F. 2d
673, 676 (CA10 1990); see Powers v. Hamilton Cty. Public
Defender Comm’n, 501 F. 3d 592, 609–610 (CA6 2007); see
also Galvan v. Alaska Dept. of Corrections, 397 F. 3d 1198,
1204 (CA9 2005) (“Courts generally do not decide issues not
raised by the parties. If they granted relief to petitioners
on grounds not urged by petitioners, respondents would be
deprived of a fair opportunity to respond, and the courts
would be deprived of the benefit of briefing” (footnote omit
ted)). Nor do they generally consider issues first mentioned
in a reply brief. Physicians Comm. for Responsible Medi
cine v. Johnson, 436 F. 3d 326, 331, n. 6 (CA2 2006); Doe v.
Beaumont Independent School Dist., 173 F. 3d 274, 299, n. 13
(CA5 1999) (Garza, J., dissenting); Doolin Security Sav.
Bank, F. S. B. v. Office of Thrift Supervision, 156 F. 3d 190,
191 (CADC 1998) (per curiam); Boone v. Carlsbad Bancor
poration, Inc., 972 F. 2d 1545, 1554, n. 6 (CA10 1992). And
it is common practice for appellate courts to refuse to con
sider issues that are mentioned only in passing. Reynolds v.
Wagner, 128 F. 3d 166, 178 (CA3 1997) (citing authorities).
The Tennessee Court of Criminal Appeals follows these
standard practices. Rule 10(b) (2008) of that court states
in order to enable Mr. Cone to present evidence and prove the factual
allegations, including those relating to his claims of ineffective assist
ance of counsel, Petition ¶¶ 15, 16, 44, R–67, 71 and 141 and of the with
holding of exculpatory evidence. Petition ¶ 41, R–139.” Reply Brief for
Petitioner-Appellant in No. 02–C–01–9403–CR–00052 (Tenn. Crim. App.),
p. 5 (hereinafter Reply Brief) (emphasis added).

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quite specifically: “Issues which are not supported by argu
ment, citation to authorities, or appropriate references to the
record will be treated as waived in this court.” The court
has applied this rule in capital cases, State v. Dellinger, 79
S. W. 3d 458, 495, 497, 503 (Tenn. 2002) (appendix to majority
opinion); Brimmer v. State, 29 S. W. 3d 497, 530 (Tenn. Crim.
App. 1998), and in others. See, e. g., State v. Faulkner,
No. E2000–00309–CCA–R3–CD, 2001 WL 378540 (Tenn.
Crim. App., Apr. 17, 2001) (73-year sentence for attempted
first-degree murder). And in both capital and noncapital
cases, the court has refused to entertain arguments raised
for the first time in a reply brief. See State v. Gerhardt,
No. W2006–02589–CCA–R3–CD, 2009 WL 160930 (Tenn.
Crim. App., Jan. 23, 2009) (noncapital case); Caruthers v.
State, 814 S. W. 2d 64, 68 (Tenn. Crim. App. 1991) (capital
case); Cammon v. State, No. M2006–01823–CCA–R3–PC,
2007 WL 2409568, *6 (Tenn. Crim. App., Aug. 23, 2007) (non
capital case).5 Thus, unless the Tennessee Court of Crimi
nal Appeals departed substantially from its general practice,
that court did not regard petitioner’s Brady claim as having
been raised on appeal.
In the decision now under review, the Sixth Circuit held
that “[t]he Tennessee courts found that Cone’s Brady claims
were ‘previously determined’ and, therefore, not cognizable
in [his] state post-conviction action.” 492 F. 3d 743, 756
(2007). In my judgment, however, there is no basis for
concluding that the Tennessee Court of Criminal Appeals
thought that any Brady issue was before it. A contrary in
5 In a footnote in his reply brief, petitioner stated that he was not waiv
ing any claim presented in the court below and asked the appellate court
to consider all those claims. See Reply Brief 3, n. 1. But the Tennes
see Court of Criminal Appeals has specifically held that claims may
not be raised on appeal in this manner. See Leonard v. State,
No. M2006–00654–CCA–R3–PC, 2007 WL 1946662, *21–*22 (July 5, 2007).

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484 CONE v. BELL
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terpretation would mean that the Tennessee Court of Crimi
nal Appeals, disregarding its own rules and standard prac
tice, entertained an issue that was not mentioned at all in
the appellant’s main brief and was mentioned only in passing
and without any development in the reply brief. It would
mean that the Tennessee Court of Criminal Appeals, having
chosen to delve into the Brady issue on its own, ruled on the
issue without even mentioning it in its opinion and without
bothering to check the record to determine whether in fact
the Brady issue had been decided on direct appeal. Such an
interpretation is utterly implausible, and it is telling that the
majority in this case cites no support for such an interpreta
tion in the Tennessee Court of Criminal Appeals’ opinion.
The Sixth Circuit’s decision on the question of procedural
default rests on an erroneous premise and must therefore
be vacated.
II
I also agree with the Court that we should not affirm the
decision below on the ground that the Brady claim lacks sub
stantive merit. After its erroneous discussion of procedural
default, the Sixth Circuit went on to discuss the merits of
petitioner’s Brady claim. In its 2001 opinion, the Court of
Appeals recognized that the prosecution’s Brady obligation
extends not only to evidence that is material to guilt but also
to evidence that is material to punishment. See Cone v.
Bell, 243 F. 3d 961, 968 (citing Pennsylvania v. Ritchie, 480
U. S. 39, 57 (1987)). But neither in that opinion nor in its
2006 opinion did the court address the materiality of the in
formation in question here in relation to petitioner’s punish
ment. See 492 F. 3d, at 756 (“A review of the allegedly with
held documents shows that this evidence would not have
overcome the overwhelming evidence of Cone’s guilt in com
mitting a brutal double murder and the persuasive testimony
that Cone was not under the influence of drugs” (emphasis
added)). Therefore, despite the strength of the arguments

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in Justice Thomas’ dissent, I would leave that question to
be decided by the Sixth Circuit on remand.
III
The Court, however, does not simply vacate and remand
to the Sixth Circuit but goes further.
First, the Court states without elaboration that petitioner
“preserved and exhausted his Brady claim in the state
court.” Ante, at 469. As I have explained, petitioner did
not fairly present his Brady claim in his prior appeal to the
Tennessee Court of Criminal Appeals, and therefore that
claim is either unexhausted or procedurally barred. If the
State is not now foreclosed from relying on the failure to
exhaust, see 28 U. S. C. § 2254(b)(3), or on procedural de
fault,6 those questions may be decided on remand.
Second, the Court remands the case to the District Court
rather than the Court of Appeals. A remand to the District
Court would of course be necessary if petitioner were enti
tled to an evidentiary hearing, but the Court does not hold
that an evidentiary hearing is either required or permitted.
In my view, unless there is to be an evidentiary hearing,
there is no reason to remand this case to the District Court.
If the only purpose of remand is to require an evaluation of
petitioner’s Brady claim in light of the present record, the
District Court is not in a superior position to conduct such a
6 Unlike exhaustion, procedural default may be waived if it is not raised
as a defense. Banks v. Dretke, 540 U. S. 668, 705 (2004) (allowing for
waiver of “procedural default” “based on the State’s litigation conduct”
(citing Gray v. Netherland, 518 U. S. 152, 166 (1996))). Here, it appears
that the State has consistently argued that petitioner’s Brady claim was
procedurally defaulted, but the State’s supporting arguments have shifted.
Whether the question of procedural default described in this opinion
should be entertained under the particular circumstances here is an in
tensely fact-bound matter that should be left for the Sixth Circuit on
remand.

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486 CONE v. BELL
Thomas, J., dissenting
review. And even if such a review is conducted in the first
instance by the District Court, that court’s decision would
be subject to de novo review in the Court of Appeals. 492
F. 3d, at 750; Cone v. Bell, 243 F. 3d, at 966–967; see United
States v. Graham, 484 F. 3d 413 (CA6 2007); United States v.
Miller, 161 F. 3d 977, 987 (CA6 1998); United States v. Phil
lip, 948 F. 2d 241, 250 (CA6 1991). Accordingly, I see no
good reason for remanding to the District Court rather than
the Court of Appeals. And if the majority has such a rea
son, it is one that it has chosen to keep to itself.
* * *
For these reasons, I would vacate the decision of the Court
of Appeals and remand to that court.
Justice Thomas, with whom Justice Scalia joins,
dissenting.
The Court affirms Gary Cone’s conviction for beating an
elderly couple to death with a blunt object. In so doing, the
majority correctly rejects Cone’s argument that his guilty
verdict was secured in violation of his rights under Brady v.
Maryland, 373 U. S. 83 (1963). The majority declines, how
ever, to decide whether the same evidence that was insuffi
cient under Brady to overturn his conviction provides a basis
for overturning his death sentence. The majority instead
remands this question to the District Court for further con
sideration because it finds that the Court of Appeals engaged
in a “summary treatment” of Cone’s Brady sentencing claim.
See ante, at 474–475.
I respectfully dissent. The Court of Appeals’ allegedly
“summary treatment” of Cone’s sentencing claim does not
justify a remand to the District Court. Cone has failed to
establish “ ‘a reasonable probability that, had the evidence
been disclosed to the defense, the result of the [sentencing]

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Thomas, J., dissenting
proceeding would have been different,’ ” Kyles v. Whitley,
514 U. S. 419, 435 (1995) (quoting United States v. Bagley,
473 U. S. 667, 682 (1985) (opinion of Blackmun, J.)). As a
result, I would affirm the judgment of the Court of Appeals.1
I
This case arises from a crime spree 29 years ago that
began with Cone’s robbery of a jewelry store in Memphis,
Tennessee, and concluded with his robbery of a drugstore in
Pompano Beach, Florida. Along the way, Cone shot a police
officer and a bystander while trying to escape the first rob
bery, attempted to shoot another man in a failed carjacking
attempt, unsuccessfully tried to force his way into a woman’s
apartment at gunpoint, and murdered 93-year-old Shipley
Todd and his 79-year-old wife, Cleopatra. When he was
tried on two counts of first-degree murder in 1982, Cone’s
sole defense was that he did not have the requisite intent to
commit first-degree murder because he was in the grip of a
chronic amphetamine psychosis. The jury rejected the de
fense and convicted Cone of both murders.
At sentencing, the Tennessee jury found beyond a reason
able doubt that four statutory aggravating factors applied to
Cone’s offense: (1) Cone had been convicted of one or more
previous felonies involving the use or threat of violence;
(2) he had knowingly created a great risk of death to two or
more persons other than the victim during his act of murder;
(3) the murder was especially heinous, atrocious, or cruel in
that it involved torture or depravity of mind; and (4) the
murder was committed for the purpose of avoiding a lawful
arrest. Tr. 2151–2152 (Apr. 23, 1982); see also State v. Cone,
1 Because I would affirm on the basis of the Court of Appeals’ alternative
holding below, I do not reach the issues of procedural default resolved by
the majority. See United States v. Atlantic Research Corp., 551 U. S. 128,
141, n. 8 (2007); Ayotte v. Planned Parenthood of Northern New Eng., 546
U. S. 320, 332 (2006); Ardestani v. INS, 502 U. S. 129, 139 (1991).

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665 S. W. 2d 87, 94–96 (Tenn. 1984). Tenn. Code Ann. § 39–
2–203(i) (1982).2 Cone argued to the jury at sentencing that
his “capacity . . . to appreciate the wrongfulness of his con
duct or to conform his conduct to the requirements of the
law was substantially impaired as a result of mental disease
or defect or intoxication which was insufficient to estab
lish a defense to the crime but which substantially affected
his judgment, ” § 39–2–203( j)(8). But the jury found
that neither this, nor any other mitigating factor, out
weighed the aggravating factors. The jury, as required by
Tennessee law, unanimously sentenced Cone to death. See
§ 39–2–203(g).
For almost three decades, Cone’s case has traveled
through the Tennessee and federal courts. This Court has
twice reversed decisions from the Court of Appeals that in
validated Cone’s conviction and sentence. See Bell v. Cone,
535 U. S. 685 (2002); Bell v. Cone, 543 U. S. 447 (2005) (per
curiam). On remand from this Court’s latest decision, the
Court of Appeals directly considered whether a handful of
police reports, law enforcement bulletins, and notes that
were allegedly withheld from Cone’s trial attorneys could
have changed the result of Cone’s trial or sentencing. And,
for the second time, the Court of Appeals held that there
was not a “ ‘reasonable probability’ ” that the evidence would
have altered the jury’s conclusion “that Cone’s prior drug
use did not vitiate his specific intent to murder his victims
and did not mitigate his culpability sufficient to avoid the
death sentence.” 492 F. 3d 743, 757 (CA6 2007). The Court
of Appeals, therefore, held that neither Cone’s conviction nor
2 The Tennessee Supreme Court later concluded that the record in
Cone’s case was doubtful as to evidence supporting the second factor given
the lapse in time between the initial events of the escape and the Todd
murders. Cone, 665 S. W. 2d, at 95. The court, however, determined
that the existence of the other three factors rendered any possible error
in this factor harmless beyond a reasonable doubt. Ibid.

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his sentence was invalid. See ibid.; Cone v. Bell, 243 F. 3d
961, 968 (CA6 2001). We should affirm the Court of Appeals
and put an end to this litigation.
II
According to the majority, the Court of Appeals’ decision
affirming Cone’s death sentence is too “summary,” ante, at
474, and the facts are such that, on further examination,
Cone “might” be able to demonstrate that it is “possible” that
the contested evidence would have persuaded the jury to
spare his life, ante, at 475. On this reasoning, the major
ity remands the case directly to the District Court for “full
consideration [of] the merits of Cone’s [sentencing] claim.”
Ante, at 476. I disagree on all counts. Remanding the sen
tencing issue to the District Court is an “unusual step” for
this Court to take. House v. Bell, 547 U. S. 518, 557 (2006)
(Roberts, C. J., concurring in judgment in part and dissent
ing in part). Furthermore, in this case, it is a step that is
legally and factually unjustified. There is not “ ‘a reasonable
probability that, had the evidence been disclosed to the de
fense, the result of the proceeding would have been differ
ent.’ ” Kyles, 514 U. S., at 433–434 (quoting Bagley, 473
U. S., at 682 (opinion of Blackmun, J.)).
A
The majority’s criticism of the Court of Appeals’ allegedly
“summary treatment” of the sentencing question is mis
placed. Before the Court of Appeals, Cone dedicated eight
pages of his opening brief to arguing that the implicated evi
dence was material to his guilt or innocence, but spent only
one paragraph arguing its materiality to his death sentence.
See Brief for Appellant in No. 99–5279 (CA6), pp. 40–48.
The Court of Appeals’ focus on the guilt phase, rather than
the sentencing phase, simply followed Cone’s lead. See 492
F. 3d, at 755 (“In his most recent brief, claiming that his

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490 CONE v. BELL
Thomas, J., dissenting
receiving the withheld evidence would have resulted in a dif
ferent sentence, Cone has made only conclusory argu
ments”).3 There is nothing defective about a judicial deci
sion that summarily rejects an abbreviated legal argument,
especially where, as here, the burden of proving the materi
ality of the contested evidence was on Cone.4
B
In remanding this matter to the District Court, the major
ity makes two critical errors—one legal and one factual—
that leave the false impression that Cone’s Brady claim has
a chance of success. First, the majority states that “[i]t is
possible that the suppressed evidence” may have convinced
the jury that Cone’s substance abuse played a mitigating role
in his crime and “[t]he evidence might also have rebutted the
State’s suggestion” that Cone’s experts were inaccurately
depicting the depth of his drug-induced impairment. Ante,
at 475 (emphasis added); see also ibid. (remanding “[b]ecause
the evidence suppressed at Cone’s trial may well have been
material to the jury’s assessment of the proper punishment
in this case” (emphasis added)). But, as the majority implic
3 The assertion by the majority, ante, at 475, n. 19, and Justice Alito,
ante, at 484 (opinion concurring in part and dissenting in part), that the
Court of Appeals did not address the merits of the sentencing issue at all
is flatly wrong. See 492 F. 3d, at 757 (rejecting Cone’s Brady claim be
cause the proffered evidence would not have altered the jury’s conclusion
“that Cone’s prior drug use did not vitiate his specific intent to murder
his victims and did not mitigate his culpability sufficient to avoid the
death sentence” (emphasis added)).
4 The majority does not attempt to justify its remand by contending that
it is necessary because the record is insufficient to decide the claim. Nor
could it persuasively contend a remand is necessary so that the District
Court can hold an evidentiary hearing. Such a hearing would shed no
additional light on the trial proceedings or the relative impeachment value
of the withheld documents. Cone himself agrees that “this Court should
resolve the merits of [his] Brady claim.” Reply Brief for Petitioner 24;
see also Brief for Respondent 26–27.

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itly acknowledges, see ibid., n. 19, this is not the correct legal
test for evaluating a Brady claim: “The mere possibility
that an item of undisclosed information might have helped
the defense, or might have affected the outcome of the trial,
does not establish ‘materiality’ in the constitutional sense,”
United States v. Agurs, 427 U. S. 97, 109–110 (1976) (empha
sis added).
Rather, this Court has made clear that the legal standard
for adjudicating such a claim is whether there is a “reason
able probability” that the jury would have been persuaded
by the allegedly withheld evidence. Kyles, supra, at 435;
Bagley, supra, at 682 (opinion of Blackmun, J.). It simply is
not sufficient, therefore, to claim that “there is a reasonable
possibility that . . . testimony might have produced a differ
ent result . . . . [P]etitioner’s burden is to establish a reason
able probability of a different result.” Strickler v. Greene,
527 U. S. 263, 291 (1999) (emphasis in original). To satisfy
the “reasonable probability” standard, Cone must show that
“the favorable evidence could reasonably be taken to put
the whole case in such a different light as to undermine
confidence” in the jury’s sentencing determination. Kyles,
supra, at 435. The Court must view the record “as a
whole,” Sawyer v. Whitley, 505 U. S. 333, 374 (1992) (Ste
vens, J., concurring in judgment), and determine whether
the absence of the disclosure prevented Cone from receiving
“ ‘a trial resulting in a [sentence] worthy of confidence,’ ”
Strickler, supra, at 290 (quoting Kyles, 514 U. S., at 434).
In the context of this case, for Cone to establish “ ‘a rea
sonable probability that, had the evidence been disclosed to
the defense, the result of the [sentencing] proceeding would
have been different,’ ” id., at 435, he must not only demon
strate that the withheld evidence would have established
that he was substantially impaired as a result of drug abuse
or withdrawal; Cone also must establish that the addition of
the allegedly withheld evidence ultimately would have led

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the jury to conclude that any mitigating factors (including
substantial impairment) outweighed all of the established ag
gravating factors, see Tenn. Code Ann. § 39–2–203(g).5
Second, the majority incorrectly claims that to prevail on
his Brady claim, Cone must demonstrate simply that the
withheld evidence supported the inference that he “was im
paired by his use of drugs around the time his crimes were
committed.” See ante, at 470. This is factually inaccurate
because there was already significant evidence of Cone’s
drug use at trial. To establish that the allegedly withheld
evidence would reasonably have had any impact on his case,
Cone must instead show that the evidence would have sup
ported his claim of substantial mental impairment from
drug use.
There was extensive evidence at trial that supported the
inference that Cone was not only a longstanding drug user,
but that he was in fact using drugs at the time of his crimes.
The State itself presented significant evidence on this point.
For example, it presented proof that officers found marijuana
cigarette butts, empty drug vials, and loose syringes in the
car that Cone abandoned immediately after the jewelry store
robbery. Tr. 1505–1509 (Apr. 19, 1982). The State also did
not challenge testimony from Cone’s mother that Cone used
drugs. Id., at 1647, 1648–1653 (Apr. 20, 1982). And, most
tellingly, the State introduced evidence that Cone was abus
ing three drugs—cocaine, Dilaudid, and Demerol—at the
time of his arrest and was suffering “slight withdrawal
5 The majority asserts that the standard under Tennessee law for dem
onstrating mental defect or intoxication as a mitigating factor at sentenc
ing is “far lesser” than the standard for demonstrating insanity in the
guilt phase of a criminal trial. Ante, at 474. But the mitigating factor
still requires a showing that Cone’s mental capacity was “substantially
impaired” as a result of mental defect. Tenn. Code Ann. § 39–2–203( j)(8).
In any event, the only authority cited by the majority for its assertion
that the standard is “far” lesser than that for insanity is Justice Ste
vens’ lone dissent in a prior appeal in this case. Ante, at 474–475.

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symptoms” from them. Id., at 1915–1916, 1920 (Apr. 22,
1982). As the Court of Appeals explained, “[i]t would not
have been news to the jurors, that Cone was a ‘drug user.’ ”
492 F. 3d, at 757.6
In contrast, what was contested by the State during trial
was Cone’s defense that his drug use was so significant that
it caused him to suffer from extreme amphetamine psychosis
at the time of the murders. One of Cone’s expert witnesses,
a neuropharmacologist, testified that by the summer of 1980,
when the crimes occurred, Cone was ingesting “ferociously
large doses” of drugs and that his increasing tolerance and
use of amphetamines caused a chronic amphetamine psycho
sis. Tr. 1736–1737, 1744–1747, 1758–1759 (Apr. 21, 1982).
The expert further testified that if a person with chronic
amphetamine psychosis were to go into withdrawal, he could
suffer extreme mood swings, “a crashing depression,” and a
state of weakness so severe that “he could barely lift him
self.” Id., at 1857–1859. In this expert’s view, these symp
toms could cause a person to “lose his mind.” Id., at 1859.
The State contradicted that testimony with significant evi
dence that Cone did not act like someone who was “out of
his mind” during the commission of his crimes. Rather, the
State argued, Cone behaved rationally during his initial Ten
6 Although there were two occasions during closing arguments where
prosecutors intimated that Cone was not a drug user, see Tr. 2014–2015,
2068 (Apr. 22, 1982), the State’s argument otherwise consistently focused
on the real issue in the case: that Cone was not so significantly affected
by his drug use around the time of his crimes that he was “out of his
mind” or “drug crazy” during the critical days of August 1980. See id.,
at 2023–2024, 2071–2084. The majority’s focus on two brief excerpts from
the State’s closing argument fails to faithfully view the record “as a whole”
for purposes of a Brady analysis. See Sawyer v. Whitley, 505 U. S. 333,
374 (1992) (Stevens, J., concurring in judgment); see also Strickler v.
Greene, 527 U. S. 263, 290–291 (1999) (finding no reasonable probability
of a different result even when prosecutor’s closing argument relied on
testimony that could have been impeached by withheld material).

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nessee robbery, his subsequent escape, his flight from Ten
nessee to Florida after the Todd murders, his Florida rob
bery, and his subsequent arrest. See, e. g., id., at 2074–2084
(Apr. 22, 1982). To substantiate this argument, the State
called Federal Bureau of Investigation (FBI) Special Agent
Eugene Flynn to the stand. Agent Flynn testified that,
when captured, Cone coherently detailed his travel from
Tennessee to Florida, explained his efforts to evade detec
tion by shaving his beard and buying new clothes, and initi
ated negotiations for a plea bargain. Id., at 1918–1921.
The State also presented testimony from a friend of Cone’s,
Ilene Blankman, that she saw no indication that Cone was
under the influence of drugs or severe withdrawal in the
days immediately following the murder of the Todds. Id.,
at 1875–1876, 1882–1883 (Apr. 21, 1982).
Viewing the record as a whole, then, it is apparent that
the contested issue at trial and sentencing was not whether
Cone used drugs, but rather the quantity of Cone’s drug use
and its effect on his mental state. Only if the evidence al
legedly withheld from Cone was relevant to this question
whether Cone suffered from extreme amphetamine psycho
sis or other substantial impairment would the evidence have
been exculpatory for purposes of Brady. See Order Deny
ing Motion for Evidentiary Hearing and Order of Partial Dis
missal, Cone v. Bell, No. 97–2312–M1/A (WD Tenn., May 15,
1998), App. to Pet. for Cert. 119a, n. 9 (explaining that “the
issue at trial was not whether Cone had ever abused any
drugs (he clearly had), but whether he was out of his mind
on amphetamines at the time of the murders”); Tr. 2115–2116
(Apr. 23, 1982).
III
With the legal and factual issues correctly framed, it be
comes clear that Cone cannot establish a reasonable probabil
ity that admission of the evidence—viewed either individu
ally or cumulatively—would have caused the jury to alter
his sentence.

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A
1
Cone first argues that he was improperly denied police re
ports that included witness statements regarding Cone’s be
havior around the time of his crime spree. The first state
ment was given by a convenience store employee, Robert
McKinney, who saw Cone the day before he robbed the Ten
nessee jewelry store. When asked whether Cone appeared
“to be drunk or high on anything,” McKinney answered,
“[w]ell he did, he acted real weird . . . he just wandered
around the store.” App. 49. But McKinney subsequently
clarified that Cone “didn’t sound drunk” and that the reason
Cone attracted his attention was because he “wasn’t acting
like a regular customer”; he was “just kinda . . . wandering”
around the store. Motion to Expand the Record, etc., in
No. 97–2312–M1 (WD Tenn.), Exh. 2, pp. 3, 4. Contrary to
the majority’s assertion, this interview is not convincing evi
dence “that Cone appeared to be ‘drunk or high’ ” when Mc-
Kinney saw him. Ante, at 470. McKinney’s clarification
that he had characterized Cone’s behavior as “weird” be
cause Cone appeared to be killing time rather than acting
like a normal shopper undermines the implication of McKin
ney’s earlier statement that Cone looked “weird” because he
might have been drunk or on drugs. Thus, there is little
chance that McKinney’s statement would have provided any
significant additional evidence that Cone was using drugs,
let alone provide sentence-changing evidence that he was
substantially impaired due to amphetamine psychosis.
The second statement was given by Charles and Debbie
Slaughter, who both witnessed Cone fleeing from police after
the jewelry store robbery and reportedly told police that he
looked “wild eyed.” App. 50. Cone had just robbed a jew
elry store, shot a police officer and a bystander, and was still
fleeing from police when seen by the Slaughters. It is thus
unlikely that their observation of a “wild eyed” man would

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have been interpreted by the jury to mean that Cone “was
suffering from chronic amphetamine psychosis at the time of
the crimes,” ante, at 471, n. 16, rather than to mean that
Cone looked like a man on the run.
The third statement is contained in a police report au
thored by an officer who helped apprehend Cone after the
Florida drugstore robbery. He reported that he saw a sus
pect “at the rear of Sambos Restaurant. Subject was ob
served to be looking about in a frenzied manner and also
appeared to be looking for a place to run.” App. 53. Noth
ing in this police report either connects Cone to drug use
or appears otherwise capable of altering the jury’s under
standing of Cone’s mental state at the time of the crimes.
It certainly makes perfect sense that Cone was “looking
about in a frenzied manner,” ibid.; he had just robbed a drug
store and was about to engage in a gun battle with police
in order to evade arrest. The police officer’s description
of Cone’s appearance under these circumstances thus does
not “undermine confidence” in Cone’s sentence. Kyles, 514
U. S., at 435.
2
The next category of documents that Cone relies upon to
establish his Brady claim are police bulletins. Some of the
bulletins were sent by Memphis Police Sergeant Roby to
neighboring jurisdictions on the day of the Todd murders
and the day after. The bulletins sought Cone’s apprehen
sion and alternatively described him as a “drug user” or a
“heavy drug user.” App. 55–58. Cone asserts that he
could have used these bulletins to impeach Sergeant Roby’s
trial testimony that the sergeant did not see any track marks
when visiting Cone in jail a week later. Tr. 1939 (Apr. 22,
1982). Cone’s reasoning is faulty for two key reasons.
First, Sergeant Roby never testified that Cone was not a
drug user. His only trial testimony on this point was simply
that he observed no “needle marks” on Cone’s arm when tak
ing hair samples from him a few days after Cone’s apprehen

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sion. Ibid. Second, the bulletins establish only “that the
police were initially cautious regarding the characteristics of
a person who had committed several heinous crimes.” App.
to Pet. for Cert. 119a, n. 9. The bulletins would not have
tended to prove that the fugitive Cone was, in fact, a heavy
drug user—let alone “out of his mind” or otherwise substan
tially impaired due to amphetamine psychosis—at the time
of his crimes.7
3
Cone also argues that material was withheld that could
have been used to impeach Ilene Blankman’s testimony that
Cone did not appear to be high or in withdrawal when she
helped him obtain a Florida driver’s license during his ef
forts to evade arrest in Florida. Tr. 1875–1882 (Apr. 21,
1982). But he again fails to meet the standard for exculpa
tory evidence set by Brady.
Cone first points to police notes of a pretrial interview
with Blankman, which did not reflect the statement she gave
at trial that she saw no track marks on Cone’s arm. App.
72–73. But Blankman was questioned at trial about her fail
ure to initially disclose this fact to police, Tr. 1903 (Apr. 21,
1982), so the jury was fully aware of the omission. Disclo
sure of the original copy of the police notes thus could not
have had any material effect on the jury’s deliberations.
Moreover, the missing notes also recorded a damning state
ment by Blankman that Cone “never used drugs around” her
and she “never saw Cone with drug paraphernalia.” App.
7 Alert bulletins sent by the FBI similarly identified Cone as a “believed
heavy drug user” or a “drug user.” App. 62–70. Cone argues that these
bulletins could have been used to impeach FBI Agent Flynn’s testimony
about Cone’s arrest in Florida. The bulletins would not have constituted
material impeachment evidence, however, for the second reason identified
above. In addition, the bulletins would not have contradicted any of FBI
Agent Flynn’s testimony; he in fact stated at trial that Cone reported
using three drugs and was undergoing mild drug withdrawal when he was
captured in Florida. Tr. 1915–1916 (Apr. 22, 1982).

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73. Thus, it is difficult to accept Cone’s argument that he
would have benefited from the introduction of notes from
Blankman’s pretrial interview. If anything, these police
notes would have undermined his mitigation argument.
Cone next relies on a report that describes a woman’s con
frontation with the prosecution team and Blankman at a res
taurant during trial. During the encounter, the woman ac
cused Blankman of lying on the stand in order to frame Cone
for the murders. Id., at 74–75. The report indicates that
the prosecutors politely declined the woman’s numerous at
tempts to discuss the merits of the case and that Blankman
said nothing. Id., at 75. Nothing about this encounter
raises doubts about Blankman’s credibility.
Last, Cone points to “correspondence in the district at
torney’s files suggest[ing] that the prosecution had been
unusually solicitous of [Blankman’s] testimony.” Brief for
Petitioner 45. But the correspondence was completely in
nocuous. One of the notes, sent in response to Blankman’s
request for a copy of her prior statement, expressed to
Blankman that her “cooperation in this particular matter is
appreciated.” App. 76. The prosecutor then sent a letter
to confirm that Blankman would testify at trial. Id., at 77.
And finally, after trial, the prosecutor sent a note to inform
Blankman of the verdict and indicate that they “certainly
appreciate[d] [her] cooperation with [them] in the trial of
Gary Bradford Cone.” Id., at 78. There is nothing about
these notes that “tend[s] to prove any fact that is both favor
able to Cone and material to his guilt or punishment.” App.
to Pet. for Cert. 116a.
B
Viewing the record as a whole, Cone has not come close to
demonstrating that there is a “reasonable probability” that
the withheld evidence, analyzed individually or cumulatively,
would have changed the result of his sentencing. Much of
the impeachment evidence identified by Cone is of no proba
tive value whatsoever. The police bulletins do not contra

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dict any of the trial testimony; the restaurant encounter was
innocuous; and the correspondence sent by prosecutors to
Blankman does not undermine her testimony or call Cone’s
mental state into doubt. If the remaining evidence has any
value to Cone, it is marginal at best. There was testimony
that Blankman did not initially tell police that Cone lacked
track marks. See Tr. 1903 (Apr. 21, 1982). McKinney clari
fied in his statement that Cone’s activity in the store was
consistent with a person killing time, not the use of drugs or
alcohol. And the behavior described by the Slaughters and
the Florida police officer is more naturally attributable to
the circumstances of Cone’s flight from the police than to
any inference that Cone was “out of his mind” or otherwise
substantially impaired due to amphetamine psychosis.
Countering the trivial value of the alleged Brady material
is the clear and overwhelming evidence that during Cone’s
crime spree, he was neither sufficiently insane to avoid a con
viction of murder nor substantially impaired by his drug use
or withdrawal-related psychosis. There was substantial ev
idence that Cone carefully planned the jewelry store robbery
and was calm in carrying it out, Tr. 974–976, 1014 (Apr. 16,
1982), 1350–1352 (Apr. 17, 1982), 1501 (Apr. 19, 1982), 2075
(Apr. 22, 1982); that he successfully eluded police after en
gaging them in a shootout, id., at 1053–1064 (Apr. 16, 1982);
that, after hiding overnight, he concocted a ruse to try to
gain illegal entry to a residence, id., at 1205–1208 (Apr. 17,
1982); that he murdered the Todds after they declined to
cooperate with his efforts to further elude police, id., at 1681
(Apr. 20, 1982); that he took steps to change his appearance
at the Todd residence and then successfully fled to Florida,
id., at 1918–1919 (Apr. 22, 1982); that he arrived in Florida
exhibiting no signs of drug use or severe withdrawal, id., at
1875–1882 (Apr. 21, 1982); that he obtained false identifica
tion in a further effort to avoid apprehension, id., at 1881–
1882; and that he denied any memory lapses and described
undergoing only minor drug withdrawal when police ar

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Thomas, J., dissenting
rested him, id., at 1919–1920 (Apr. 22, 1982). Given this
wealth of evidence, there is no “reasonable probability” that
the jury would have found that Cone was entitled to the sub
stantial impairment mitigator had the evidence he seeks
been made available to him.
And even if Cone could have presented this evidence to
the jury at sentencing and established an entitlement to this
mitigator, he still has not demonstrated a reasonable proba
bility that it would have outweighed all of the aggravating
factors supporting the jury’s death sentence. See id., at
2151–2154 (Apr. 23, 1982). In its decision on direct appeal,
the Tennessee Supreme Court was well aware of the evi
dence regarding the “degree and extent of [Cone’s] drug
abuse.” Cone, 665 S. W. 2d, at 90. As part of its required
independent review of whether the mitigation evidence was
sufficiently substantial to outweigh the aggravating factors,
see Tenn. Code Ann. § 39–2–205, the Tennessee court never
theless concluded that the sentence was “not in any way dis
proportionate under all of the circumstances, including the
brutal murders of two elderly defenseless persons by an es
caping armed robber who had terrorized a residential neigh
borhood for twenty-four hours.” 665 S. W. 2d, at 95–96.
None of Cone’s proffered evidence places that conclusion,
made by both the jury and the Tennessee Supreme Court,
“in such a different light as to undermine confidence” in
Cone’s sentence. Kyles, 514 U. S., at 435; see also Strickler,
527 U. S., at 296.
IV
This Court should not vacate and remand lower court deci
sions based on nothing more than the vague suspicion that
error might be present, or because the court below could
have been more clear. This is especially so where, as here,
the record before the Court is adequate to evaluate Cone’s
Brady claims with respect to both the guilt and sentencing
phases of his trial. The Court’s willingness to return the
sentencing issue to the District Court without any firm con

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viction that an error was committed by the Court of Appeals
is inconsistent with our established practice and disrespect
ful to the lower courts that have considered this case.
Worse still, the inevitable result will be years of additional
delay in the execution of a death sentence lawfully imposed
by a Tennessee jury. Because I would affirm the judgment
below, I respectfully dissent.