Atkins v. Virginia

United States Supreme Court

536 U.S. 304, 122 S.Ct. 2242, 153 L.Ed.2d 335 (2002)

 

Justice Stevens delivered the opinion of the Court.

 

             Those mentally retarded persons who meet the law’s requirements for criminal responsibility should be tried and punished when they commit crimes. Because of their disabilities in areas of reasoning, judgment, and control of their impulses, however, they do not act with the level of moral culpability that characterizes the most serious adult criminal conduct. Moreover, their impairments can jeopardize the reliability and fairness of capital proceedings against mentally retarded defendants. Presumably for these reasons, in the 13 years since we decided Penry v. Lynaugh, 492 U. S. 302 (1989), the American public, legislators, scholars, and judges have deliberated over the question whether the death penalty should ever be imposed on a mentally retarded criminal. The consensus reflected in those deliberations informs our answer to the question presented by this case: whether such executions are “cruel and unusual punishments” prohibited by the Eighth Amendment to the Federal Constitution.

 

I

 

             Petitioner, Daryl Renard Atkins, was convicted of abduction, armed robbery, and capital murder, and sentenced to death. At approximately midnight on August 16, 1996, Atkins and William Jones, armed with a semiautomatic handgun, abducted Eric Nesbitt, robbed him of the money on his person, drove him to an automated teller machine in his pickup truck where cameras recorded their withdrawal of additional cash, then took him to an isolated location where he was shot eight times and killed.

 

             Jones and Atkins both testified in the guilt phase of Atkins’ trial. Each confirmed most of the details in the other’s account of the incident, with the important exception that each stated that the other had actually shot and killed Nesbitt. Jones’ testimony, which was both more coherent and credible than Atkins’, was obviously credited by the jury and was sufficient to establish Atkins’ guilt. At the penalty phase of the trial, the State introduced victim impact evidence and proved two aggravating circumstances: future dangerousness and “vileness of the offense.” To prove future dangerousness, the State relied on Atkins’ prior felony convictions as well as the testimony of four victims of earlier robberies and assaults. To prove the second aggravator, the prosecution relied upon the trial record, including pictures of the deceased’s body and the autopsy report.

 

             In the penalty phase, the defense relied on one witness, Dr. Evan Nelson, a forensic psychologist who had evaluated Atkins before trial and concluded that he was “mildly mentally retarded.” His conclusion was based on interviews with people who knew Atkins, a review of school and court records, and the administration of a standard intelligence test which indicated that Atkins had a full scale IQ of 59.

 

             The jury sentenced Atkins to death, but the Virginia Supreme Court ordered a second sentencing hearing because the trial court had used a misleading verdict form. … At the resentencing, Dr. Nelson again testified. The State presented an expert rebuttal witness, Dr. Stanton Samenow, who expressed the opinion that Atkins was not mentally retarded, but rather was of “average intelligence, at least,” and diagnosable as having antisocial personality disorder. … The jury again sentenced Atkins to death.

 

             The Supreme Court of Virginia affirmed the imposition of the death penalty. … Atkins did not argue before the Virginia Supreme Court that his sentence was disproportionate to penalties imposed for similar crimes in Virginia, but he did contend “that he is mentally retarded and thus cannot be sentenced to death.” … The majority of the state court rejected this contention, relying on our holding in Penry. … The Court was “not willing to commute Atkins’ sentence of death to life imprisonment merely because of his IQ score.” …

 

             Justice Hassell and Justice Koontz dissented. They rejected Dr. Samenow’s opinion that Atkins possesses average intelligence as “incredulous as a matter of law,” and concluded that “the imposition of the sentence of death upon a criminal defendant who has the mental age of a child between the ages of 9 and 12 is excessive.” … In their opinion, “it is indefensible to conclude that individuals who are mentally retarded are not to some degree less culpable for their criminal acts. By definition, such individuals have substantial limitations not shared by the general population. A moral and civilized society diminishes itself if its system of justice does not afford recognition and consideration of those limitations in a meaningful way.”

 

             Because of the gravity of the concerns expressed by the dissenters, and in light of the dramatic shift in the state legislative landscape that has occurred in the past 13 years, we granted certiorari to revisit the issue that we first addressed in the Penry case. …

 

II

 

             The Eighth Amendment succinctly prohibits “excessive” sanctions. It provides: “Excessive bail shall not be required, nor excessive fines imposed, nor cruel and unusual punishments inflicted.” In Weems v. United States, 217 U. S. 349 (1910), we held that a punishment of 12 years jailed in irons at hard and painful labor for the crime of falsifying records was excessive. We explained “that it is a precept of justice that punishment for crime should be graduated and proportioned to the offense.” … We have repeatedly applied this proportionality precept in later cases interpreting the Eighth Amendment. … Thus, even though “imprisonment for ninety days is not, in the abstract, a punishment which is either cruel or unusual,” it may not be imposed as a penalty for “the ‘status’ of narcotic addiction,” because such a sanction would be excessive. …

 

             A claim that punishment is excessive is judged not by the standards that prevailed in 1685 when Lord Jeffreys presided over the “Bloody Assizes” or when the Bill of Rights was adopted, but rather by those that currently prevail. As Chief Justice Warren explained in his opinion in Trop v. Dulles, 356 U. S. 86 (1958): “The basic concept underlying the Eighth Amendment is nothing less than the dignity of man. ... The Amendment must draw its meaning from the evolving standards of decency that mark the progress of a maturing society.”

 

            …We have pinpointed that the “clearest and most reliable objective evidence of contemporary values is the legislation enacted by the country’s legislatures.” Relying in part on such legislative evidence, we have held that death is an impermissibly excessive punishment for the rape of an adult woman, … or for a defendant who neither took life, attempted to take life, nor intended to take life. …

 

Guided by our approach in these cases, we shall first review the judgment of legislatures that have addressed the suitability of imposing the death penalty on the mentally retarded and then consider reasons for agreeing or disagreeing with their judgment.

 

III

 

             The parties have not called our attention to any state legislative consideration of the suitability of imposing the death penalty on mentally retarded offenders prior to 1986. In that year, the public reaction to the execution of a mentally retarded murderer in Georgia apparently led to the enactment of the first state statute prohibiting such executions. In 1988, when Congress enacted legislation reinstating the federal death penalty, it expressly provided that a “sentence of death shall not be carried out upon a person who is mentally retarded.” In 1989, Maryland enacted a similar prohibition. It was in that year that we decided Penry, and concluded that those two state enactments, “even when added to the 14 States that have rejected capital punishment completely, do not provide sufficient evidence at present of a national consensus.” …

 

             Much has changed since then. Responding to the national attention received by the Bowden execution and our decision in Penry, state legislatures across the country began to address the issue. In 1990 Kentucky and Tennessee enacted statutes similar to those in Georgia and Maryland, as did New Mexico in 1991, and Arkansas, Colorado, Washington, Indiana, and Kansas in 1993 and 1994. In 1995, when New York reinstated its death penalty, it emulated the Federal Government by expressly exempting the mentally retarded. Nebraska followed suit in 1998. There appear to have been no similar enactments during the next two years, but in 2000 and 2001 six more States--South Dakota, Arizona, Connecticut, Florida, Missouri, and North Carolina--joined the procession. The Texas Legislature unanimously adopted a similar bill, and bills have passed at least one house in other States, including Virginia and Nevada.

 

             It is not so much the number of these States that is significant, but the consistency of the direction of change. Given the well-known fact that anticrime legislation is far more popular than legislation providing protections for persons guilty of violent crime, the large number of States prohibiting the execution of mentally retarded persons (and the complete absence of States passing legislation reinstating the power to conduct such executions) provides powerful evidence that today our society views mentally retarded offenders as categorically less culpable than the average criminal. The evidence carries even greater force when it is noted that the legislatures that have addressed the issue have voted overwhelmingly in favor of the prohibition. Moreover, even in those States that allow the execution of mentally retarded offenders, the practice is uncommon. Some States, for example New Hampshire and New Jersey, continue to authorize executions, but none have been carried out in decades. Thus there is little need to pursue legislation barring the execution of the mentally retarded in those States. And it appears that even among those States that regularly execute offenders and that have no prohibition with regard to the mentally retarded, only five have executed offenders possessing a known IQ less than 70 since we decided Penry. The practice, therefore, has become truly unusual, and it is fair to say that a national consensus has developed against it.

 

             To the extent there is serious disagreement about the execution of mentally retarded offenders, it is in determining which offenders are in fact retarded. In this case, for instance, the Commonwealth of Virginia disputes that Atkins suffers from mental retardation. Not all people who claim to be mentally retarded will be so impaired as to fall within the range of mentally retarded offenders about whom there is a national consensus. …

 

IV

 

             This consensus unquestionably reflects widespread judgment about the relative culpability of mentally retarded offenders, and the relationship between mental retardation and the penological purposes served by the death penalty. Additionally, it suggests that some characteristics of mental retardation undermine the strength of the procedural protections that our capital jurisprudence steadfastly guards.

 

             As discussed above, clinical definitions of mental retardation require not only subaverage intellectual functioning, but also significant limitations in adaptive skills such as communication, self-care, and self-direction that became manifest before age 18. Mentally retarded persons frequently know the difference between right and wrong and are competent to stand trial. Because of their impairments, however, by definition they have diminished capacities to understand and process information, to communicate, to abstract from mistakes and learn from experience, to engage in logical reasoning, to control impulses, and to understand the reactions of others. There is no evidence that they are more likely to engage in criminal conduct than others, but there is abundant evidence that they often act on impulse rather than pursuant to a premeditated plan, and that in group settings they are followers rather than leaders. Their deficiencies do not warrant an exemption from criminal sanctions, but they do diminish their personal culpability.

 

             In light of these deficiencies, our death penalty jurisprudence provides two reasons consistent with the legislative consensus that the mentally retarded should be categorically excluded from execution. First, there is a serious question as to whether either justification that we have recognized as a basis for the death penalty applies to mentally retarded offenders. Gregg v. Georgia, 428 U. S. 153, 183 (1976), identified “retribution and deterrence of capital crimes by prospective offenders” as the social purposes served by the death penalty. Unless the imposition of the death penalty on a mentally retarded person “measurably contributes to one or both of these goals, it ‘is nothing more than the purposeless and needless imposition of pain and suffering,’ and hence an unconstitutional punishment.”

 

             With respect to retribution--the interest in seeing that the offender gets his “just deserts”--the severity of the appropriate punishment necessarily depends on the culpability of the offender. Since Gregg, our jurisprudence has consistently confined the imposition of the death penalty to a narrow category of the most serious crimes. If the culpability of the average murderer is insufficient to justify the most extreme sanction available to the State, the lesser culpability of the mentally retarded offender surely does not merit that form of retribution. Thus, pursuant to our narrowing jurisprudence, which seeks to ensure that only the most deserving of execution are put to death, an exclusion for the mentally retarded is appropriate.

 

             With respect to deterrence--the interest in preventing capital crimes by prospective offenders—“it seems likely that ‘capital punishment can serve as a deterrent only when murder is the result of premeditation and deliberation.’” Exempting the mentally retarded from that punishment will not affect the “cold calculus that precedes the decision” of other potential murderers. … Indeed, that sort of calculus is at the opposite end of the spectrum from behavior of mentally retarded offenders. The theory of deterrence in capital sentencing is predicated upon the notion that the increased severity of the punishment will inhibit criminal actors from carrying out murderous conduct. Yet it is the same cognitive and behavioral impairments that make these defendants less morally culpable--for example, the diminished ability to understand and process information, to learn from experience, to engage in logical reasoning, or to control impulses--that also make it less likely that they can process the information of the possibility of execution as a penalty and, as a result, control their conduct based upon that information. Nor will exempting the mentally retarded from execution lessen the deterrent effect of the death penalty with respect to offenders who are not mentally retarded. Such individuals are unprotected by the exemption and will continue to face the threat of execution. Thus, executing the mentally retarded will not measurably further the goal of deterrence.

 

             The reduced capacity of mentally retarded offenders provides a second justification for a categorical rule making such offenders ineligible for the death penalty. The risk “that the death penalty will be imposed in spite of factors which may call for a less severe penalty… is enhanced, not only by the possibility of false confessions, but also by the lesser ability of mentally retarded defendants to make a persuasive showing of mitigation in the face of prosecutorial evidence of one or more aggravating factors. Mentally retarded defendants may be less able to give meaningful assistance to their counsel and are typically poor witnesses, and their demeanor may create an unwarranted impression of lack of remorse for their crimes. As Penry demonstrated, moreover, reliance on mental retardation as a mitigating factor can be a two-edged sword that may enhance the likelihood that the aggravating factor of future dangerousness will be found by the jury. … Mentally retarded defendants in the aggregate face a special risk of wrongful execution.

 

             Our independent evaluation of the issue reveals no reason to disagree with the judgment of “the legislatures that have recently addressed the matter” and concluded that death is not a suitable punishment for a mentally retarded criminal. We are not persuaded that the execution of mentally retarded criminals will measurably advance the deterrent or the retributive purpose of the death penalty. Construing and applying the Eighth Amendment in the light of our “evolving standards of decency,” we therefore conclude that such punishment is excessive and that the Constitution “places a substantive restriction on the State’s power to take the life” of a mentally retarded offender.

 

 

Chief Justice Rehnquist, with whom Justice Scalia and Justice Thomas join, dissenting. …

 

 

Justice Scalia, with whom the Chief Justice and Justice Thomas join, dissenting.

 

             Today’s decision is the pinnacle of our Eighth Amendment death-is-different jurisprudence. Not only does it, like all of that jurisprudence, find no support in the text or history of the Eighth Amendment; it does not even have support in current social attitudes regarding the conditions that render an otherwise just death penalty inappropriate. Seldom has an opinion of this Court rested so obviously upon nothing but the personal views of its
members.

 

I

 

             I begin with a brief restatement of facts that are abridged by the Court but important to understanding this case. After spending the day drinking alcohol and smoking marijuana, petitioner Daryl Renard Atkins and a partner in crime drove to a convenience store, intending to rob a customer. Their victim was Eric Nesbitt, an airman from Langley Air Force Base, whom they abducted, drove to a nearby automated teller machine, and forced to withdraw $200. They then drove him to a deserted area, ignoring his pleas to leave him unharmed. According to the co-conspirator, whose testimony the jury evidently credited, Atkins ordered Nesbitt out of the vehicle and, after he had taken only a few steps, shot him one, two, three, four, five, six, seven, eight times in the thorax, chest, abdomen, arms, and legs.

 

             The jury convicted Atkins of capital murder. At resentencing (the Virginia Supreme Court affirmed his conviction but remanded for resentencing because the trial court had used an improper verdict form, … the jury heard extensive evidence of petitioner’s alleged mental retardation. A psychologist testified that petitioner was mildly mentally retarded with an IQ of 59, that he was a “slow learne[r],” … who showed a “lack of success in pretty much every domain of his life,” and that he had an “impaired” capacity to appreciate the criminality of his conduct and to conform his conduct to the law. Petitioner’s family members offered additional evidence in support of his mental retardation claim. … The State contested the evidence of retardation and presented testimony of a psychologist who found “absolutely no evidence other than the IQ score ... indicating that [petitioner] was in the least bit mentally retarded” and concluded that petitioner was “of average intelligence, at least.” …

 

             The jury also heard testimony about petitioner’s 16 prior felony convictions for robbery, attempted robbery, abduction, use of a firearm, and maiming. The victims of these offenses provided graphic depictions of petitioner’s violent tendencies. … The Supreme Court of Virginia affirmed petitioner’s sentence. …

 

II

 

             As the foregoing history demonstrates, petitioner’s mental retardation was a central issue at sentencing. The jury concluded, however, that his alleged retardation was not a compelling reason to exempt him from the death penalty in light of the brutality of his crime and his long demonstrated propensity for violence. “In upsetting this particularized judgment on the basis of a constitutional absolute,” the Court concludes that no one who is even slightly mentally retarded can have sufficient “moral responsibility to be subjected to capital punishment for any crime. As a sociological and moral conclusion that is implausible; and it is doubly implausible as an interpretation of the United States Constitution.” …

 

             Under our Eighth Amendment jurisprudence, a punishment is “cruel and unusual” if it falls within one of two categories: “those modes or acts of punishment that had been considered cruel and unusual at the time that the Bill of Rights was adopted,” … and modes of punishment that are inconsistent with modern “standards of decency,” as evinced by objective indicia, the most important of which is “legislation enacted by the country’s legislatures.” …

 

             The Court makes no pretense that execution of the mildly mentally retarded would have been considered “cruel and unusual” in 1791. Only the severely or profoundly mentally retarded, commonly known as “idiots,” enjoyed any special status under the law at that time. They, like lunatics, suffered a “deficiency in will” rendering them unable to tell right from wrong. …

 

             The Court is left to argue, therefore, that execution of the mildly retarded is inconsistent with the “evolving standards of decency that mark the progress of a maturing society.” … Before today, our opinions consistently emphasized that Eighth Amendment judgments regarding the existence of social “standards” “should be informed by objective factors to the maximum possible extent” and “should not be, or appear to be, merely the subjective views of individual Justices.” … “First” among these objective factors are the “statutes passed by society’s elected representatives,” …  because it “will rarely if ever be the case that the Members of this Court will have a better sense of the evolution in views of the American people than do their elected representatives.” …

 

             The Court pays lip service to these precedents as it miraculously extracts a “national consensus” forbidding execution of the mentally retarded, … from the fact that 18 States--less than half (47%) of the 38 States that permit capital punishment (for whom the issue exists)--have very recently enacted legislation barring execution of the mentally retarded. Even that 47% figure is a distorted one. If one is to say, as the Court does today, that all executions of the mentally retarded are so morally repugnant as to violate our national “standards of decency,” surely the “consensus” it points to must be one that has set its righteous face against all such executions. Not 18 States, but only seven--18% of death penalty jurisdictions--have legislation of that scope. Eleven of those that the Court counts enacted statutes prohibiting execution of mentally retarded defendants convicted after, or convicted of crimes committed after, the effective date of the legislation; those already on death row, or consigned there before the statute’s effective date, or even (in those States using the date of the crime as the criterion of retroactivity) tried in the future for murders committed many years ago, could be put to death. That is not a statement of absolute moral repugnance, but one of current preference between two tolerable approaches. Two of these States permit execution of the mentally retarded in other situations as well: Kansas apparently permits execution of all except the severely mentally retarded; New York permits execution of the mentally retarded who commit murder in a correctional facility. …

 

             But let us accept, for the sake of argument, the Court’s faulty count. That bare number of States alone--18--should be enough to convince any reasonable person that no “national consensus” exists. How is it possible that agreement among 47% of the death penalty jurisdictions amounts to “consensus”? Our prior cases have generally required a much higher degree of agreement before finding a punishment cruel and unusual on “evolving standards” grounds. …

 

             Moreover, a major factor that the Court entirely disregards is that the legislation of all 18 States it relies on is still in its infancy. The oldest of the statutes is only 14 years old; five were enacted last year; over half were enacted within the past eight years. Few, if any, of the States have had sufficient experience with these laws to know whether they are sensible in the long term. It is “myopic to base sweeping constitutional principles upon the narrow experience of [a few] years.”

 

             The Court attempts to bolster its embarrassingly feeble evidence of “consensus” with the following: “It is not so much the number of these States that is significant, but the consistency of the direction of change.” … But in what other direction could we possibly see change? Given that 14 years ago all the death penalty statutes included the mentally retarded, any change (except precipitate undoing of what had just been done) was bound to be in the one direction the Court finds significant enough to overcome the lack of real consensus. That is to say, to be accurate the Court’s “consistency-of-the-direction-of-change” point should be recast into the following unimpressive observation: “No State has yet undone its exemption of the mentally retarded, one for as long as 14 whole years.” In any event, reliance upon “trends,” even those of much longer duration than a mere 14 years, is a perilous basis for constitutional adjudication. …

 

III

 

… The genuinely operative portion of the opinion … is the Court’s statement of the reasons why it agrees with the contrived consensus it has found, that the “diminished capacities” of the mentally retarded render the death penalty excessive. … The Court’s analysis rests on two fundamental assumptions: (1) that the Eighth Amendment prohibits excessive punishments, and (2) that sentencing juries or judges are unable to account properly for the “diminished capacities” of the retarded. The first assumption is wrong. … The Eighth Amendment is addressed to always-and-everywhere “cruel” punishments, such as the rack and the thumbscrew. But where the punishment is in itself permissible, “[t]he Eighth Amendment is not a ratchet, whereby a temporary consensus on leniency for a particular crime fixes a permanent constitutional maximum, disabling the States from giving effect to altered beliefs and responding to changed social conditions.” … The second assumption--inability of judges or juries to take proper account of mental retardation--is not only unsubstantiated, but contradicts the immemorial belief, here and in England, that they play an indispensable role in such matters. …

 

             Proceeding from these faulty assumptions, the Court gives two reasons why the death penalty is an excessive punishment for all mentally retarded offenders. First, the “diminished capacities” of the mentally retarded raise a “serious question” whether their execution contributes to the “social purposes” of the death penalty, viz., retribution and deterrence. … Retribution is not advanced, the argument goes, because the mentally retarded are no more culpable than the average murderer, whom we have already held lacks sufficient culpability to warrant the death penalty. … Who says so? Is there an established correlation between mental acuity and the ability to conform one’s conduct to the law in such a rudimentary matter as murder? Are the mentally retarded really more disposed (and hence more likely) to commit willfully cruel and serious crime than others? In my experience, the opposite is true: being childlike generally suggests innocence rather than brutality.

 

             Assuming, however, that there is a direct connection between diminished intelligence and the inability to refrain from murder, what scientific analysis can possibly show that a mildly retarded individual who commits an exquisite torture-killing is “no more culpable” than the “average” murderer in a holdup-gone-wrong or a domestic dispute? Or a moderately retarded individual who commits a series of 20 exquisite torture-killings? Surely culpability, and deservedness of the most severe retribution, depends not merely (if at all) upon the mental capacity of the criminal (above the level where he is able to distinguish right from wrong) but also upon the depravity of the crime--which is precisely why this sort of question has traditionally been thought answerable not by a categorical rule of the sort the Court today imposes upon all trials, but rather by the sentencer’s weighing of the circumstances (both degree of retardation and depravity of crime) in the particular case. The fact that juries continue to sentence mentally retarded offenders to death for extreme crimes shows that society’s moral outrage sometimes demands execution of retarded offenders. By what principle of law, science, or logic can the Court pronounce that this is wrong? There is none. Once the Court admits (as it does) that mental retardation does not render the offender morally blameless, … there is no basis for saying that the death penalty is never appropriate retribution, no matter how heinous the crime. As long as a mentally retarded offender knows “the difference between right and wrong,” … only the sentencer can assess whether his retardation reduces his culpability enough to exempt him from the death penalty for the particular murder in question.

 

             As for the other social purpose of the death penalty that the Court discusses, deterrence: That is not advanced, the Court tells us, because the mentally retarded are “less likely” than their non-retarded counterparts to “process the information of the possibility of execution as a penalty and ... control their conduct based upon that information.” … Of course this leads to the same conclusion discussed earlier--that the mentally retarded (because they are less deterred) are more likely to kill--which neither I nor the society at large believes. In any event, even the Court does not say that all mentally retarded individuals cannot “process the information of the possibility of execution as a penalty and . . . control their conduct based upon that information”; it merely asserts that they are “less likely” to be able to do so. But surely the deterrent effect of a penalty is adequately vindicated if it successfully deters many, but not all, of the target class. Virginia’s death penalty, for example, does not fail of its deterrent effect simply because some criminals are unaware that Virginia has the death penalty. In other words, the supposed fact that some retarded criminals cannot fully appreciate the death penalty has nothing to do with the deterrence rationale, but is simply an echo of the arguments denying a retribution rationale, discussed and rejected above. I am not sure that a murderer is somehow less blameworthy if (though he knew his act was wrong) he did not fully appreciate that he could die for it; but if so, we should treat a mentally retarded murderer the way we treat an offender who may be “less likely” to respond to the death penalty because he was abused as a child. We do not hold him immune from capital punishment, but require his background to be considered by the sentencer as a mitigating factor. …

 

             The Court throws one last factor into its grab bag of reasons why execution of the retarded is “excessive” in all cases: Mentally retarded offenders “face a special risk of wrongful execution” because they are less able “to make a persuasive showing of mitigation,” “to give meaningful assistance to their counsel,” and to be effective witnesses. … “Special risk” is pretty flabby language (even flabbier than “less likely”)--and I suppose a similar “special risk” could be said to exist for just plain stupid people, inarticulate people, even ugly people. If this unsupported claim has any substance to it (which I doubt) it might support a due process claim in all criminal prosecutions of the mentally retarded; but it is hard to see how it has anything to do with an Eighth Amendment claim that execution of the mentally retarded is cruel and unusual. …

 

             Today’s opinion adds one more to the long list of substantive and procedural requirements impeding imposition of the death penalty imposed under this Court’s assumed power to invent a death-is-different jurisprudence. None of those requirements existed when the Eighth Amendment was adopted, and some of them were not even supported by current moral consensus. … There is something to be said for popular abolition of the death penalty; there is nothing to be said for its incremental abolition by this Court.

 

             This newest invention promises to be more effective than any of the others in turning the process of capital trial into a game. One need only read the definitions of mental retardation adopted by the American Association of Mental Retardation and the American Psychiatric Association … to realize that the symptoms of this condition can readily be feigned. And whereas the capital defendant who feigns insanity risks commitment to a mental institution until he can be cured (and then tried and executed), … the capital defendant who feigns mental retardation risks nothing at all. The mere pendency of the present case has brought us petitions by death row inmates claiming for the first time, after multiple habeas petitions, that they are retarded. …

 

             Perhaps these practical difficulties will not be experienced by the minority of capital-punishment States that have very recently changed mental retardation from a mitigating factor (to be accepted or rejected by the sentencer) to an absolute immunity. Time will tell--and the brief time those States have had the new disposition in place (an average of 6.8 years) is surely not enough. But if the practical difficulties do not appear, and if the other States share the Court’s perceived moral consensus that all mental retardation renders the death penalty inappropriate for all crimes, then that majority will presumably follow suit. But there is no justification for this Court’s pushing them into the experiment--and turning the experiment into a permanent practice--on constitutional pretext. …