Justice O’Connor delivered the opinion of
the Court.
In
Penry v.
Lynaugh, 492
U.S. 302 (1989)
(Penry I), we held that the Texas
capital sentencing scheme provided a constitutionally inadequate
vehicle for jurors to consider and give effect to the mitigating
evidence of mental retardation and childhood abuse the petitioner
had presented. The petitioner in this case argues that the same
scheme was inadequate for jurors to give effect to his evidence of
low intelligence. The Texas courts rejected his claim, and a
Federal District Court denied his petition for a writ of habeas
corpus. We conclude that “reasonable jurists would find the
district court’s assessment of the constitutional claims debatable
or wrong,”
Slack v.
McDaniel ,
529 U.S.
473, 484 (2000) , and therefore hold that a certificate of
appealability should have issued.
I
Petitioner Robert Tennard was convicted by a jury of capital
murder in October 1986. The evidence presented at trial indicated
that Tennard and two accomplices killed two of his neighbors and
robbed their house. Tennard himself stabbed one of the victims to
death, and one of the accomplices killed the other victim with a
hatchet.
During the penalty phase of the trial, defense counsel called
only one witness—Tennard’s parole officer—who testified that
Tennard’s Department of Corrections record from a prior
incarceration indicated that he had an IQ of 67. App. 28–29. He
testified that the IQ test would have been administered as a matter
of course.
Ibid. The report, which indicated that Tennard
was 17 years old at the time it was prepared, was admitted into
evidence. On cross-examination, the parole officer testified that
he did not know who had administered the test.
Id., at 30.
The government introduced evidence in the penalty phase regarding a
prior conviction for rape, committed when Tennard was 16. The rape
victim testified that she had escaped through a window after
Tennard permitted her to go to the bathroom to take a bath,
promising him she wouldn’t run away.
Id., at 16–17.
The jury was instructed to consider the appropriate punishment
by answering the two “special issues” used at the time in Texas to
establish whether a sentence of life imprisonment or death would be
imposed:
“Was the conduct of the defendant, Robert James Tennard, that
caused the death of the deceased committed deliberately and with
the reasonable expectation that the death of the deceased or
another would result?”
Id., at 69 (the “deliberateness
special issue”).
“Is there a probability that the defendant, Robert James
Tennard, would commit criminal acts of violence that would
constitute a continuing threat to society?”
Id., at 70
(the “future dangerousness special issue”).
In his penalty-phase closing argument, defense counsel relied on
both the IQ score and the rape victim’s testimony to suggest that
Tennard’s limited mental faculties and gullible nature mitigated
his culpability:
“Tennard has got a 67 IQ. The same guy that told this poor
unfortunate woman [the rape victim] that was trying to work that
day, ‘Well, if I let you in there, will you leave?’ And he believed
her. This guy with the 67 IQ, and she goes in and, sure enough, she
escapes, just like she should have. That is uncontroverted
testimony before you, that we have got a man before us that has got
an intelligence quotient . . . that is that low.”
Id., at
51.
In rebuttal, the prosecution suggested that the low
IQ
evidence was simply irrelevant to the question of
mitigation:
“But whether he has a low IQ or not is not really the issue.
Because the legislature, in asking you to address that question
[the future dangerousness special issue], the reasons why he became
a danger are not really relevant. The fact that he is a danger,
that the evidence shows he’s a danger, is the criteria to use in
answering that question.”
Id., at 60.
The jury answered both special issues in the affirmative, and
Tennard was accordingly sentenced to death.
Unsuccessful on direct appeal, Tennard sought state
postconviction relief. He argued that, in light of the instructions
given to the jury, his death sentence had been obtained in
violation of the Eighth Amendment as interpreted by this Court in
Penry I . In that case, we had held that “it is not enough
simply to allow the defendant to present mitigating evidence to the
sentencer. The sentencer must also be able to consider and give
effect to that evidence in imposing sentence.”
Penry I ,
supra, at 319; see also
Penry v.
Johnson, 532 U.S.
782, 797 (2001)
(Penry II) (describing “ ‘give effect
to’ ” language of
Penry I as “the key” to that decision).
We concluded that the same two special issues that were presented
to Tennard’s jury (plus a third immaterial to the questions now
before us) were insufficient for the jury in Penry’s case to
consider and give effect to Penry’s evidence of mental retardation
and childhood abuse, and therefore ran afoul of the Eighth
Amendment.
Penry I , 492 U. S., at 319–328. His mental
retardation evidence, we held, “ ‘had relevance to [his] moral
culpability beyond the scope of the [deliberateness] special
verdict questio[n]’ ” because “[p]ersonal culpability is not solely
a function of a defendant’s capacity to act ‘deliberately.’ ”
Id. , at 322 (some brackets in original). Moreover,
because the “evidence concerning Penry’s mental retardation
indicated that one effect of his retardation is his inability to
learn from his mistakes,” his retardation was relevant to the
future dangerousness special issue “only as an
aggravating
factor.”
Id., at 323. As to the evidence of childhood
abuse, we held that the two special issues simply failed to
“provide a vehicle for the jury to give [it] mitigating effect.”
Id., at 322–324.
The Texas Court of Criminal Appeals rejected Tennard’s
Penry claim.
Ex parte Tennard ,
960 S.W.2d 57 (1997) (en banc). Writing for a plurality of
four, Presiding Judge McCormick observed that the definition of
mental retardation adopted in Texas involves three components (“(1)
subaverage general intellectual functioning; (2) concurrent
deficits in adaptive behavior;
and (3) onset during the
early development period,”
id., at 60), and concluded:
“[Tennard’s] evidence of a low IQ score, standing alone, does not
meet this definition. Qualitatively and quantitatively, [Tennard’s]
low IQ evidence does not approach the level of Johnny Paul Penry’s
evidence of mental retardation… . [W]e find no evidence in this
record that applicant is mentally retarded.”
Id., at
61.
The plurality went on to consider whether Tennard would be
entitled to relief under
Penry even if his low IQ fell
“within
Penry ’s definition of mental retardation.” 960 S.
W. 2d, at 61. It held that he would not. The court explained that,
unlike the evidence presented in Penry’s case, “there is no
evidence … [that Tennard’s] low IQ rendered him unable to
appreciate the wrongfulness of his conduct when he committed the
offense, or that his low IQ rendered him unable to learn from his
mistakes … or control his impulses … .”
Id., at 62. It
found there was “no danger” that the jury would have given the
evidence “
only aggravating effect in answering” the
future dangerousness special issue, and that the low IQ and
gullibility evidence was not beyond the jury’s effective reach
because the jury “could have used this evidence for a ‘no’ answer”
to the deliberateness special issue. Ibid.
Two judges concurred separately, and wrote that “this Court has
sustained a Penry claim
only when there is evidence of
mental retardation. But even in those cases, the evidence of mental
retardation was always something more than what was presented in
this case.” 960 S. W. 2d, at 64 (opinion of Meyers, J.) (citations
omitted). Taking a more permissive view of evidence of impaired
intellectual functioning than did the plurality (“[F]or
Penry purposes, courts should not distinguish between
mental retardation and dementia,” even though the onset of the
latter “may occur after age eighteen,”
id., at 65), the
concurring judges nevertheless concluded that “the record does not
contain sufficient evidence to support” Tennard’s
Penry
claim. 960 S. W. 2d
, at 63. The concurring judges also
rejected Tennard’s contention that “evidence of an IQ of below 70
alone requires a ‘
Penry instruction’ ” because published
opinions of the Texas courts had uniformly required more.
Id., at 67.
Judge Baird dissented, maintaining that the Court of Criminal
Appeals had “consistent[ly]” held, in the wake of
Penry I
, that “evidence of mental retardation cannot be adequately
considered within the statutory” special issues. 960 S. W. 2d, at
67. The court had strayed from its precedent, Judge Baird wrote,
and instead of asking simply whether the jury had a vehicle for
considering the mitigating evidence, had “weigh[ed] the sufficiency
of [Tennard’s] mitigating evidence.”
Id., at 70. Judges
Overstreet and Womack dissented without opinion.
Id., at
63.
Tennard sought federal habeas corpus relief. The District Court
denied his petition.
Tennard v.
Johnson, Civ.
Action No. H–98–4238 (S D Tex., July 25, 2000), App. 121. The court
began by observing that “[e]vidence of a single low score on an
unidentified intelligence test is not evidence that Tennard was
mentally retarded.”
Id., at 128. It then considered
whether the 67 IQ score was “within ‘the effective reach’ of the
jury.”
Ibid. Noting that “Tennard’s low IQ score was not
concealed from the jury; it was in evidence, and both sides argued
its significance for punishment,” the court concluded that the jury
had adequate means, in the two special issues, by which to give
effect to that mitigating evidence.
Id., at 129. The court
subsequently denied Tennard a certificate of appealability (COA).
Civ. Action No. H–98–4238 (S D Tex. Oct. 17, 2000), see App. 2.
The Court of Appeals for the Fifth Circuit, after full briefing
and oral argument, issued an opinion holding that Tennard was not
entitled to a COA because his
Penry claim was not
debatable among jurists of reason.
Tennard v.
Cockrell,
284 F.3d 591 (2002). The court began by stating the test
applied in the Fifth Circuit to
Penry claims, which
involves a threshold inquiry into whether the petitioner presented
“constitutionally relevant” mitigating evidence, that is, evidence
of a “ ‘uniquely severe permanent handicap with which the defendant
was burdened through no fault of his own,’ ” and evidence that “
‘the criminal act was attributable to this severe permanent
condition.’ ” 284 F. 3d, at 595.
The court then held that Tennard was not entitled to a COA, for
two reasons: First, it held that evidence of low IQ alone does not
constitute a uniquely severe condition, and rejected Tennard’s
claim that his evidence was of mental retardation, not just low IQ,
because no evidence had been introduced tying his IQ score to
retardation.
Id., at 596. Second, it held that even if
Tennard’s evidence was mental retardation evidence, his claim must
fail because he did not show that the crime he committed was
attributable to his low IQ.
Id., at 596–597. Judge Dennis
dissented, concluding that the Texas court’s application of
Penry was unreasonable and that Tennard was entitled to
habeas relief. 284 F. 3d, at 597–604.
Tennard filed a petition for certiorari, and this Court granted
the writ, vacated the judgment, and remanded for further
consideration in light of
Atkins v.
Virginia,
536 U.S.
304 (2002) .
Tennard v.
Cockrell, 537 U.S.
802 (2002) . The Fifth Circuit took the remand to be for
consideration of a substantive
Atkins claim. It observed
that “Tennard has never argued that the Eighth Amendment prohibits
his execution” and reinstated its prior panel opinion.
317 F.3d 476,
477 (2003). We again granted certiorari. 540 U.S. 945 (2003)
.
II
A
A COA should issue if the applicant has “made a substantial
showing of the denial of a constitutional right,” 28 U. S. C.
§2253(c)(2), which we have interpreted to require that the
“petitioner must demonstrate that reasonable jurists would find the
district court’s assessment of the constitutional claims debatable
or wrong.”
Slack v.
McDaniel , 529 U. S., at 484;
see also
Miller-El v.
Cockrell, 537 U.S.
322, 336 (2003) (“Under the controlling standard, a petitioner
must ‘sho[w] that reasonable jurists could debate whether (or, for
that matter, agree that) the petition should have been resolved in
a different manner or that the issues presented were “adequate to
deserve encouragement to proceed further” ’ ”). The petitioner’s
arguments ultimately must be assessed under the deferential
standard required by 28 U. S. C. §2254(d)(1): Relief may not be
granted unless the state court adjudication “resulted in a decision
that was contrary to, or involved an unreasonable application of,
clearly established Federal law, as determined by the Supreme Court
of the United States.”
The State has never disputed that Tennard’s
Penry claim
was properly preserved for federal habeas review. Not only did the
state court consider the question on the merits, we note that the
issue was also raised by defense counsel prior to trial in a motion
to set aside the indictment on the ground, among others, that the
“Texas capital murder statutes do not explicitly allow the
consideration of any specific mitigating circumstances at the
punishment phase of the prosecution and, consequently, are
violative of the accused’s right to be free from cruel and unusual
punishment and are also void for vagueness.” Defendant’s Motion to
Set Aside the Indictment, in Cause No. 431127 (248th Jud. Dist. Ct.
Harris County, Tex., May 28, 1986), p. 4.
B
Despite paying lipservice to the principles guiding issuance of
a COA,
Tennard v.
Cockrell, supra, at 594, the
Fifth Circuit’s analysis proceeded along a distinctly different
track. Rather than examining the District Court’s analysis of the
Texas court decision, it invoked its own restrictive gloss on Penry
I:
“In reviewing a
Penry claim, we must determine whether
the mitigating evidence introduced at trial was constitutionally
relevant and beyond the effective reach of the jury. … To be
constitutionally relevant, ‘the evidence must show (1) a uniquely
severe permanent handicap with which the defendant was burdened
through no fault of his own, … and (2) that the criminal act was
attributable to this severe permanent condition.’ ” 284 F. 3d, at
595 (quoting
Davis v.
Scott, 51 F. 3d, 457,
460–461 (CA5 1998)).
This test for “constitutional relevance,” characterized by the
State at oral argument as a threshold “screening test,” Tr. of Oral
Arg.10, 28, appears to be applied uniformly in the Fifth Circuit to
Penry claims. See,
e.g., Bigby v.
Cockrell ,
340 F.3d 259, 273 (2003);
Robertson v.
Cockrell ,
325 F.3d 243, 251 (2003) (en banc);
Smith v.
Cockrell ,
311 F.3d 661, 680 (2002);
Blue v.
Cockrell ,
298 F.3d 318, 320–321 (2002);
Davis v.
Scott
,
51 F.3d 457, 460–461 (1995). Only after the court finds that
certain mitigating evidence is “constitutionally relevant” will it
consider whether that evidence was within “the ‘effective reach of
the jur[y].’ ”
E.g., Smith, supra, at 680 (court
asks whether evidence was constitutionally relevant and, “if so,”
will consider whether it was within jury’s effective reach). In the
decision below, the Fifth Circuit concluded that Tennard was
“precluded from establishing a
Penry claim” because his
low IQ evidence bore no nexus to the crime, and so did not move on
to the “effective reach” question. 284 F. 3d, at 597.
The Fifth Circuit’s test has no foundation in the decisions of
this Court. Neither
Penry I nor its progeny screened
mitigating evidence for “constitutional relevance” before
considering whether the jury instructions comported with the Eighth
Amendment. Indeed, the mitigating evidence presented in
Penry
I was
concededly relevant, see Tr. of Oral Arg., O.
T. 1988, No. 87–6177, pp. 34–36, so even if limiting principles
regarding relevance were suggested in our opinion—and we do not
think they were—they could not have been material to the
holding.
When we addressed directly the relevance standard applicable to
mitigating evidence in capital cases in
McKoy v.
North
Carolina, 494 U.S.
433, 440–441 (1990) , we spoke in the most expansive terms. We
established that the “meaning of relevance is no different in the
context of mitigating evidence introduced in a capital sentencing
proceeding” than in any other context, and thus the general
evidentiary standard—“ ‘ “any tendency to make the existence of any
fact that is of consequence to the determination of the action more
probable or less probable than it would be without the evidence” ’
”—applies.
Id., at 440 (quoting
New Jersey v.
T. L. O., 469 U.S.
325, 345 (1985) ). We quoted approvingly from a dissenting
opinion in the state court: “ ‘Relevant mitigating evidence is
evidence which tends logically to prove or disprove some fact or
circumstance which a fact-finder could reasonably deem to have
mitigating value.” 494 U. S., at 440 (quoting
State v.
McKoy , 323 N. C. 1, 55–56, 372 S. E. 2d, 12, 45 (1988)
(opinion of Exum, C. J.)). Thus, a State cannot bar “the
consideration of … evidence if the sentencer could reasonably find
that it warrants a sentence less than death.” 494 U. S., at
441.
Once this low threshold for relevance is met, the “ Eighth
Amendment requires that the jury be able to consider and give
effect to” a capital defendant’s mitigating evidence.
Boyde v.
California, 494
U.S. 370, 377–378 (1990) (citing
Lockett v.
Ohio, 438 U.S.
586 (1978) ;
Eddings v.
Oklahoma, 455 U.S.
104 (1982) ;
Penry I, 492 U.S.
302 (1989) ); see also
Payne v.
Tennessee,
501 U.S.
808, 822 (1991) (“We have held that a State cannot preclude the
sentencer from considering ‘any relevant mitigating evidence’ that
the defendant proffers in support of a sentence less than death… .
[V]irtually no limits are placed on the relevant mitigating
evidence a capital defendant may introduce concerning his own
circumstances” (quoting
Eddings ,
supra , at
114)).
The Fifth Circuit’s test is inconsistent with these principles.
Most obviously, the test will screen out any positive aspect of a
defendant’s character, because good character traits are neither
“handicap[s]” nor typically traits to which criminal activity is
“attributable.” In
Skipper v.
South Carolina,
476 U.S.
1, 5 (1986) , however, we made clear that good-character
evidence can be evidence that, “[u]nder
Eddings , … may
not be excluded from the sentencer’s consideration.” We observed
that even though the petitioner’s evidence of good conduct in jail
did “not relate specifically to petitioner’s culpability for the
crime he committed, there is no question but that such [evidence] …
would be ‘mitigating’ in the sense that [it] might serve ‘as a
basis for a sentence less than death.’
Lockett ,
supra , at 604”
id., at 4–5 (citation omitted).
Such evidence, we said, of “a defendant’s disposition to make a
well-behaved and peaceful adjustment to life in prison is … by its
nature relevant to the sentencing determination.”
Id., at
7. Of course, the Texas courts might reasonably conclude that
evidence of good conduct in jail was within the jury’s effective
reach via the future dangerousness special issue. See
Franklin v.
Lynaugh, 487
U.S. 164, 177–178 (1988) (plurality opinion);
id., at
185–186 (
O’Connor, J. , concurring in judgment). But
under the Fifth Circuit’s test, the evidence would have been
screened out before the time came to consider that question.
In Tennard’s case, the Fifth Circuit invoked both the “uniquely
severe” and the “nexus” elements of its test to deny him relief
under
Penry I .
Tennard v.
Cockrell, 284
F. 3d, at 596 (contrasting Tennard’s low IQ evidence, which did
“not constitute a uniquely severe condition,” with mental
retardation, a “severe permanent condition”);
id., at
596–597 (concluding that
Penry claims “must fail because
[Tennard] made no showing at trial that the criminal act was
attributable” to his condition).*
* Neither
ground provided an adequate reason to fail to reach the heart of
Tennard’s
Penry claims.
We have never denied that gravity has a place in the relevance
analysis, insofar as evidence of a trivial feature of the
defendant’s character or the circumstances of the crime is unlikely
to have any tendency to mitigate the defendant’s culpability. See
Skipper ,
supra, at 7, n. 2 (“We do not hold that
all facets of the defendant’s ability to adjust to prison life must
be treated as relevant and potentially mitigating. For example, we
have no quarrel with the statement … that ‘how often [the
defendant] will take a shower’ is irrelevant to the sentencing
determination” (quoting
State v.
Plath , 281 S.
C. 1, 15,
313 S.E.2d 619, 627 (1984)). However, to say that only those
features and circumstances that a panel of federal appellate judges
deems to be “severe” (let alone “uniquely severe”) could have such
a tendency is incorrect. Rather, the question is simply whether the
evidence is of such a character that it “might serve ‘as a basis
for a sentence less than death,’ ”
Skipper ,
supra, at 5.
The Fifth Circuit was likewise wrong to have refused to consider
the debatability of the
Penry question on the ground that
Tennard had not adduced evidence that his crime was attributable to
his low IQ. In
Atkins v.
Virginia, 536 U.S.
304, 316 (2002) , we explained that impaired intellectual
functioning is inherently mitigating: “[T]oday our society views
mentally retarded offenders as categorically less culpable than the
average criminal.” Nothing in our opinion suggested that a mentally
retarded individual must establish a nexus between her mental
capacity and her crime before the Eighth Amendment prohibition on
executing her is triggered. Equally, we cannot countenance the
suggestion that low IQ evidence is not relevant mitigating
evidence—and thus that the
Penry question need not even be
asked—unless the defendant also establishes a nexus to the
crime.
The State claims that “the Fifth Circuit’s
Penry I
jurisprudence is not at issue” in this case. Brief for Respondent
35, n. 21; Tr. of Oral Arg. 33. To the contrary, that jurisprudence
is directly at issue because the Fifth Circuit denied Tennard
relief on the ground that he did not satisfy the requirements
imposed by its “constitutional relevance” test. As we have
explained, the Fifth Circuit’s screening test has no basis in our
precedents and, indeed, is inconsistent with the standard we have
adopted for relevance in the capital sentencing context. We
therefore hold that the Fifth Circuit assessed Tennard’s
Penry claim under an improper legal standard. Cf.
Miller-El v.
Cockrell, 537 U. S., at 341
(holding, on certiorari review of the denial of a COA, that the
Fifth Circuit had applied an incorrect standard by improperly
merging the requirements of two statutory sections).
C
We turn to the analysis the Fifth Circuit should have conducted:
Has Tennard “demonstrate[d] that reasonable jurists would find the
district court’s assessment of the constitutional claims debatable
or wrong”?
Slack v.
McDaniel , 529 U. S., at 484.
We conclude that he has.
Reasonable jurists could conclude that the low IQ evidence
Tennard presented was relevant mitigating evidence. Evidence of
significantly impaired intellectual functioning is obviously
evidence that “might serve ‘as a basis for a sentence less than
death,’ ”
Skipper , 476 U. S., at 5; see also,
e.g., Wiggins v.
Smith, 539 U.S.
510, 535 (2003) (observing, with respect to individual with IQ
of 79, that “Wiggins[’] … diminished mental capacitie[s] further
augment his mitigation case”);
Burger v.
Kemp,
483 U.S.
776 n. 7 (1987) (noting that petitioner “had an IQ of 82 and
functioned at the level of a 12-year-old child,” and later that
“[i]n light of petitioner’s youth at the time of the offense, …
testimony that his ‘mental and emotional development were at a
level several years below his chronological age’ could not have
been excluded by the state court” (quoting
Eddings , 455
U. S., at 116)).
Reasonable jurists also could conclude that the Texas Court of
Criminal Appeals’ application of
Penry to the facts of
Tennard’s case was unreasonable. The relationship between the
special issues and Tennard’s low IQ evidence has the same essential
features as the relationship between the special issues and Penry’s
mental retardation evidence. Impaired intellectual functioning has
mitigating dimension beyond the impact it has on the individual’s
ability to act deliberately. See
Penry I , 492 U. S., at
322. A reasonable jurist could conclude that the jury might well
have given Tennard’s low IQ evidence aggravating effect in
considering his future dangerousness, not only as a matter of
probable inference from the evidence but also because the
prosecutor told them to do so: “[W]hether he has a low IQ or not is
not really the issue. Because the legislature, in asking you to
address that question, the reasons why he became a danger are not
really relevant. The fact that he is a danger, that the evidence
shows he’s a danger, is the criteria to use in answering that
question.” App 60. Indeed, the prosecutor’s comments pressed
exactly the most problematic interpretation of the special issues,
suggesting that Tennard’s low IQ was irrelevant in mitigation, but
relevant to the question whether he posed a future danger.
* * *
We hold that the Fifth Circuit’s “uniquely severe permanent
handicap” and “nexus” tests are incorrect, and we reject them. We
hold that reasonable jurists would find debatable or wrong the
District Court’s disposition of Tennard’s low-IQ-based
Penry claim, and that Tennard is therefore entitled to a
certificate of appealability. The judgment of the United States
Court of Appeals for the Fifth Circuit is reversed, and the case is
remanded for further proceedings consistent with this opinion.
It is so ordered.
Notes
* * The Fifth Circuit stated that “a majority of the Court of
Criminal Appeals found ‘no evidence in this record that [Tennard]
is mentally retarded.’ ” 284 F. 3d, at 596–597. As described above,
however, that was the conclusion of a four-judge plurality; the
narrowest and thus controlling opinion on this point, correctly
described by the Fifth Circuit as “conclud[ing] that there was not
enough evidence of mental retardation in the record to support
Tennard’s claim,” id., at 596, n. 5 (emphasis added), is Judge
Meyers’ concurring opinion.