Court Bars Execution Of Mentally Retarded

6 to 3 Ruling Cites Ban In Death-Penalty States

 Atkins v. Virginia Supreme Court Decision

By Charles Lane

Washington Post Staff Writer

June 21, 2002

 The Supreme Court yesterday abolished the execution of mentally retarded offenders, imposing one of the most significant restrictions on who can be given the death penalty since the court permitted states to resume capital punishment in 1976.

 By 6 to 3, the court held that a recent wave of statutes banning the practice in 18 of 38 death-penalty states showed that a national consensus against it had formed, a consensus strong enough to warrant classifying all death sentences for the mentally retarded as "cruel and unusual punishment" prohibited by the Constitution.

 Coming amid an upsurge in public concern over flaws in the administration of the death penalty, the ruling represented a change from a position the court had taken as recently as 1989, when the justices, by 5 to 4, gave executions of the mentally retarded their conditional approval. At that time, only two death-penalty states banned executions of the retarded.

 "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," Justice John Paul Stevens wrote in a majority opinion joined by Justices Sandra Day O'Connor, Anthony M. Kennedy, David H. Souter, Ruth Bader Ginsburg and Stephen G. Breyer.

 Thus, the court said, the objectives of capital punishment -- deterring murder and exacting retribution for it -- do not apply to persons of well-below-average measured intelligence.

 Additionally, in its clearest signal yet that the court has taken notice of recent DNA exonerations of death-row inmates, the majority said that the mentally retarded's "impairments can jeopardize the reliability and fairness of capital proceedings against mentally retarded defendants."

 Stevens added a footnote mentioning the cases of two retarded former death-row inmates in Illinois and Virginia who confessed to murders that later DNA evidence proved they did not commit.

 Though its symbolic impact was strong and immediate, the precise contours of the ruling's practical effects remained unclear. Profound mental retardation, a condition so debilitating that the court has previously said it would disqualify someone from execution, was not at issue in the case. Rather, the dispute centered on mildly mentally retarded people -- defined by mental health professionals as those who have an IQ between about 50 and 70 and have experienced difficulty adapting to school and social and family life since before the age of 18.

 Some 35 such people have been executed since 1976, according to the Death Penalty Information Center. Human Rights Watch, another anti-death penalty group, says there are 200 to 300 retarded inmates among the death row population of more than 3,700 convicted murderers.

 Yet except for citing the broad definitions of mild mental retardation, the majority said it would be up to the states to develop precise standards and procedures for determining who should qualify for the new exemption from execution.

 The decision also appears to apply retroactively. In recent weeks, as its opinion in this case was being prepared, the court granted stays of execution to three death-row inmates raising last-minute claims of mental retardation.

 The court's decision crowned with victory a national campaign by opponents of capital punishment, who had argued in state legislatures and the courts that executing the retarded not only violated the Constitution, but also put the United States at odds with international human rights laws.

 In its opinion yesterday, the Supreme Court said its view was reinforced by polls showing most Americans opposed the practice, as well as by the arguments presented in friend-of-the-court briefs from the European Union, professional groups such as the American Psychological Association and religious groups such as the U.S. Catholic Conference.

 "Concerns remain about many other aspects of the death penalty," said Richard Dieter, executive director of the Death Penalty Information Center, a Washington nonprofit that opposes capital punishment. "But at least today we have stopped a practice that most Americans and the rest of the world find abhorrent."

 But supporters of capital punishment said the court had opened the door to hundreds of phony claims of retardation, each of which would take years to litigate.

 "If you're still breathing and have been convicted and sentenced to death, now you need to get to a phone and call your lawyer to have a shrink come interview you, and tell him a square looks like a circle to you," said Michael Rushford, president of the California-based Criminal Justice Legal Foundation, which filed a friend-of-the-court brief urging the court to leave its 1989 ruling in place.

 But James W. Ellis, a professor of law at the University of New Mexico, who argued the case against executing the retarded before the justices, said malingering "hasn't been a problem in any of the states" that have abolished the practice recently. "You'd have to figure out how to do it as a kid, to deal with the definition's requirement of onset before age 18."

 Still, concerns about such possible abuse of the court's ruling were also expressed yesterday by the court's three most conservative members, Chief Justice William H. Rehnquist and Justices Antonin Scalia and Clarence Thomas, who dissented in the case, as they had dissented from the court's recent stays of execution.

 Scalia read a summary of his opinion from the bench after Stevens finished reading the opinion for the court, a gesture usually reserved only for those cases in which a justice disagrees especially strongly with the majority.

 Noting that 20 of the 38 death-penalty states still allowed capital punishment for the retarded, Scalia, his voice rising at times, accused the majority of discovering an "artificial" national consensus and using it to short-circuit the legislative processes of the states so as to enshrine as an unchangeable constitutional rule the moral judgment of "really good lawyers."

 "Seldom has an opinion of this court rested so obviously upon nothing but the personal views of its members," Scalia wrote.

 Scalia also took a dig at the majority's acknowledgment of the anti-death penalty views of the U.S. Catholic Conference, which is grappling with a child sex-abuse scandal, noting that "the attitudes of that body regarding crime and punishment are so far from being representative, even of the views of Catholics, that they are currently the object of intense national (and ecumenical) criticism."

 Yesterday's case, Atkins v. Virginia, No. 00-8452, involved Daryl Renard Atkins, 23, who has been on death row in Virginia since 1998 for the 1996 abduction and murder of Eric Nesbitt, a U.S. airman assigned to Langley Air Force Base in Hampton, Va.

 After a day of drinking and drug use, Atkins and co-defendant William A. Jones grabbed Nesbitt outside a convenience store and forced him to withdraw money from an ATM. Nesbitt was shot eight times and died. The murder weapon was never recovered.

 Atkins offered police a detailed account of his involvement when he was arrested. He was convicted in a trial at which the most sensational testimony against him came from Jones, who pleaded guilty in return for a life sentence. Jones told the jury that Atkins had been the triggerman in the murder, which Atkins has always disputed.

 A mental health expert appointed by attorneys for Atkins said he has an IQ of 59. Atkins had a long record of violent crime but had never lived on his own or held a job. Backed by its own expert witness, the Virginia attorney general's office said Atkins was intelligent enough to understand and plan a crime.

 The Virginia Supreme Court split 5 to 2 on Atkins's appeal, with two justices saying Atkins's sentence should be commuted to life without parole.

 The U.S. Supreme Court agreed to hear Atkins's case in September, after it dropped a North Carolina death-row inmate's case that became moot when that state passed a law abolishing execution of the mentally retarded.

U.S. Supreme Court bars execution of retarded 

   David Stout 

June 21, 2002

WASHINGTON In one of the most important capital punishment cases in years, the U.S. Supreme Court ruled Thursday that executing killers who are mentally retarded is unconstitutional.

.The 6-to-3 ruling not only spared the life of Daryl Atkins, a Virginia inmate, at least for now, but also could save scores of other death-row prisoners in the 20 states that still allow the execution of mentally retarded murderers. Thirty-eight of the 50 states have capital punishment.

.The ruling could also affect cases for years to come, as murder suspects of borderline intelligence argue through their lawyers that they should be classified as retarded and therefore should not face the death penalty.

.Mental health professionals generally regard those with an I.Q. below 70 as retarded. But the definitions used by medical professionals and those upon which judges and lawyers rely do not always coincide, especially in trying to determine a defendant's ability to know right from wrong and to assist in his own defense.

.Justice John Paul Stevens wrote the majority opinion, declaring that much has changed in the United States in the 13 years since the Supreme Court refused to recognize a constitutional bar to putting retarding people to death.

.In 1989, the court decided that "there is insufficient evidence of a national consensus" from which to conclude that such executions violated the country's "evolving standards of decency."

.But since then, "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," Stevens said.

.In fact, the number of states that have the death penalty but prohibit execution of the mentally retarded has grown to 18 today from 2 in 1989. That shift is powerful evidence that under the country's "evolving standards of decency" there is a growing consensus that executing retarded people is "cruel and unusual punishment" under the Eighth Amendment to the Constitution and that it therefore cannot be allowed, the majority held.

.Joining Stevens in the majority were Justices Sandra Day O'Connor, Anthony Kennedy, David Souter, Ruth Bader Ginsburg and Stephen Breyer.

.Chief Justice William Rehnquist dissented, along with Justices Antonin Scalia and Clarence Thomas. Rehnquist said that the majority relied too heavily on opinion polls in reaching its conclusion, and he was disdainful of any allusion to the lack of a death penalty in many other countries. "The viewpoints of other countries simply are not relevant," he said.

.Writing separately, Scalia said, "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." Scalia accused the majority of "thrashing about" in its search for a national consensus.

.O'Connor played a crucial role in the case, siding with the majority and reversing her stand of 13 years ago, when she wrote the last big decision on capital punishment and retarded defendants.

.Like many other cases that give rise to court rulings of profound importance, this one, Atkins v. Virginia, was born under horrible circumstances.

.Atkins, then 18, and a friend were seeking money to buy beer one night in the summer of 1996. They abducted a serviceman from Langley Air Force Base in Virginia, Eric Nesbitt, in the parking lot of a store, forced him to withdraw money from a teller machine, and then drove him to a deserted area. Ignoring his pleas for mercy, they shot him to death.

.At the trial, one psychiatrist called Atkins "mildly retarded."

.Atkins, convicted as the one who actually shot Nesbitt, was sentenced by the jury to death. The Virginia Supreme Court upheld the sentence last year and the case was argued before the U.S. Court on Feb. 21.

.Although Atkins's I.Q. has been measured at 59, Virginia has maintained that he is not in fact retarded, an issue that will have to be resolved in the state courts, now that the Supreme Court has ruled in his favor on the Eighth Amendment question. 

< < Back to Start of Article WASHINGTON In one of the most important capital punishment cases in years, the U.S. Supreme Court ruled Thursday that executing killers who are mentally retarded is unconstitutional.

.The 6-to-3 ruling not only spared the life of Daryl Atkins, a Virginia inmate, at least for now, but also could save scores of other death-row prisoners in the 20 states that still allow the execution of mentally retarded murderers. Thirty-eight of the 50 states have capital punishment.

.The ruling could also affect cases for years to come, as murder suspects of borderline intelligence argue through their lawyers that they should be classified as retarded and therefore should not face the death penalty.

.Mental health professionals generally regard those with an I.Q. below 70 as retarded. But the definitions used by medical professionals and those upon which judges and lawyers rely do not always coincide, especially in trying to determine a defendant's ability to know right from wrong and to assist in his own defense.

.Justice John Paul Stevens wrote the majority opinion, declaring that much has changed in the United States in the 13 years since the Supreme Court refused to recognize a constitutional bar to putting retarding people to death.

.In 1989, the court decided that "there is insufficient evidence of a national consensus" from which to conclude that such executions violated the country's "evolving standards of decency."

.But since then, "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," Stevens said.

.In fact, the number of states that have the death penalty but prohibit execution of the mentally retarded has grown to 18 today from 2 in 1989. That shift is powerful evidence that under the country's "evolving standards of decency" there is a growing consensus that executing retarded people is "cruel and unusual punishment" under the Eighth Amendment to the Constitution and that it therefore cannot be allowed, the majority held.

.Joining Stevens in the majority were Justices Sandra Day O'Connor, Anthony Kennedy, David Souter, Ruth Bader Ginsburg and Stephen Breyer.

.Chief Justice William Rehnquist dissented, along with Justices Antonin Scalia and Clarence Thomas. Rehnquist said that the majority relied too heavily on opinion polls in reaching its conclusion, and he was disdainful of any allusion to the lack of a death penalty in many other countries. "The viewpoints of other countries simply are not relevant," he said.

.Writing separately, Scalia said, "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." Scalia accused the majority of "thrashing about" in its search for a national consensus.

.O'Connor played a crucial role in the case, siding with the majority and reversing her stand of 13 years ago, when she wrote the last big decision on capital punishment and retarded defendants.

.Like many other cases that give rise to court rulings of profound importance, this one, Atkins v. Virginia, was born under horrible circumstances.

.Atkins, then 18, and a friend were seeking money to buy beer one night in the summer of 1996. They abducted a serviceman from Langley Air Force Base in Virginia, Eric Nesbitt, in the parking lot of a store, forced him to withdraw money from a teller machine, and then drove him to a deserted area. Ignoring his pleas for mercy, they shot him to death.

.At the trial, one psychiatrist called Atkins "mildly retarded."

.Atkins, convicted as the one who actually shot Nesbitt, was sentenced by the jury to death. The Virginia Supreme Court upheld the sentence last year and the case was argued before the U.S. Court on Feb. 21.

.Although Atkins's I.Q. has been measured at 59, Virginia has maintained that he is not in fact retarded, an issue that will have to be resolved in the state courts, now that the Supreme Court has ruled in his favor on the Eighth Amendment question. WASHINGTON In one of the most important capital punishment cases in years, the U.S. Supreme Court ruled Thursday that executing killers who are mentally retarded is unconstitutional.

.The 6-to-3 ruling not only spared the life of Daryl Atkins, a Virginia inmate, at least for now, but also could save scores of other death-row prisoners in the 20 states that still allow the execution of mentally retarded murderers. Thirty-eight of the 50 states have capital punishment.

.The ruling could also affect cases for years to come, as murder suspects of borderline intelligence argue through their lawyers that they should be classified as retarded and therefore should not face the death penalty.

.Mental health professionals generally regard those with an I.Q. below 70 as retarded. But the definitions used by medical professionals and those upon which judges and lawyers rely do not always coincide, especially in trying to determine a defendant's ability to know right from wrong and to assist in his own defense.

.Justice John Paul Stevens wrote the majority opinion, declaring that much has changed in the United States in the 13 years since the Supreme Court refused to recognize a constitutional bar to putting retarding people to death.

.In 1989, the court decided that "there is insufficient evidence of a national consensus" from which to conclude that such executions violated the country's "evolving standards of decency."

.But since then, "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," Stevens said.

.In fact, the number of states that have the death penalty but prohibit execution of the mentally retarded has grown to 18 today from 2 in 1989. That shift is powerful evidence that under the country's "evolving standards of decency" there is a growing consensus that executing retarded people is "cruel and unusual punishment" under the Eighth Amendment to the Constitution and that it therefore cannot be allowed, the majority held.

.Joining Stevens in the majority were Justices Sandra Day O'Connor, Anthony Kennedy, David Souter, Ruth Bader Ginsburg and Stephen Breyer.

.Chief Justice William Rehnquist dissented, along with Justices Antonin Scalia and Clarence Thomas. Rehnquist said that the majority relied too heavily on opinion polls in reaching its conclusion, and he was disdainful of any allusion to the lack of a death penalty in many other countries. "The viewpoints of other countries simply are not relevant," he said.

.Writing separately, Scalia said, "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." Scalia accused the majority of "thrashing about" in its search for a national consensus.

.O'Connor played a crucial role in the case, siding with the majority and reversing her stand of 13 years ago, when she wrote the last big decision on capital punishment and retarded defendants.

.Like many other cases that give rise to court rulings of profound importance, this one, Atkins v. Virginia, was born under horrible circumstances.

.Atkins, then 18, and a friend were seeking money to buy beer one night in the summer of 1996. They abducted a serviceman from Langley Air Force Base in Virginia, Eric Nesbitt, in the parking lot of a store, forced him to withdraw money from a teller machine, and then drove him to a deserted area. Ignoring his pleas for mercy, they shot him to death.

.At the trial, one psychiatrist called Atkins "mildly retarded."

.Atkins, convicted as the one who actually shot Nesbitt, was sentenced by the jury to death. The Virginia Supreme Court upheld the sentence last year and the case was argued before the U.S. Court on Feb. 21.

.Although Atkins's I.Q. has been measured at 59, Virginia has maintained that he is not in fact retarded, an issue that will have to be resolved in the state courts, now that the Supreme Court has ruled in his favor on the Eighth Amendment question. WASHINGTON In one of the most important capital punishment cases in years, the U.S. Supreme Court ruled Thursday that executing killers who are mentally retarded is unconstitutional..

The 6-to-3 ruling not only spared the life of Daryl Atkins, a Virginia inmate, at least for now, but also could save scores of other death-row prisoners in the 20 states that still allow the execution of mentally retarded murderers. Thirty-eight of the 50 states have capital punishment.

.The ruling could also affect cases for years to come, as murder suspects of borderline intelligence argue through their lawyers that they should be classified as retarded and therefore should not face the death penalty.

.Mental health professionals generally regard those with an I.Q. below 70 as retarded. But the definitions used by medical professionals and those upon which judges and lawyers rely do not always coincide, especially in trying to determine a defendant's ability to know right from wrong and to assist in his own defense.

.Justice John Paul Stevens wrote the majority opinion, declaring that much has changed in the United States in the 13 years since the Supreme Court refused to recognize a constitutional bar to putting retarding people to death.

.In 1989, the court decided that "there is insufficient evidence of a national consensus" from which to conclude that such executions violated the country's "evolving standards of decency."

.But since then, "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," Stevens said.

.In fact, the number of states that have the death penalty but prohibit execution of the mentally retarded has grown to 18 today from 2 in 1989. That shift is powerful evidence that under the country's "evolving standards of decency" there is a growing consensus that executing retarded people is "cruel and unusual punishment". 

WASHINGTON 

In one of the most important capital punishment cases in years, the U.S. Supreme Court ruled Thursday that executing killers who are mentally retarded is unconstitutional.

.The 6-to-3 ruling not only spared the life of Daryl Atkins, a Virginia inmate, at least for now, but also could save scores of other death-row prisoners in the 20 states that still allow the execution of mentally retarded murderers. Thirty-eight of the 50 states have capital punishment.

.The ruling could also affect cases for years to come, as murder suspects of borderline intelligence argue through their lawyers that they should be classified as retarded and therefore should not face the death penalty.

.Mental health professionals generally regard those with an I.Q. below 70 as retarded. But the definitions used by medical professionals and those upon which judges and lawyers rely do not always coincide, especially in trying to determine a defendant's ability to know right from wrong and to assist in his own defense.

.Justice John Paul Stevens wrote the majority opinion, declaring that much has changed in the United States in the 13 years since the Supreme Court refused to recognize a constitutional bar to putting retarding people to death.

.In 1989, the court decided that "there is insufficient evidence of a national consensus" from which to conclude that such executions violated the country's "evolving standards of decency."

.But since then, "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," Stevens said.

.In fact, the number of states that have the death penalty but prohibit execution of the mentally retarded has grown to 18 today from 2 in 1989. That shift is powerful evidence that under the country's "evolving standards of decency" there is a growing consensus that executing retarded people is "cruel and unusual punishment" under the Eighth Amendment to the Constitution and that it therefore cannot be allowed, the majority held.

.Joining Stevens in the majority were Justices Sandra Day O'Connor, Anthony Kennedy, David Souter, Ruth Bader Ginsburg and Stephen Breyer.

.Chief Justice William Rehnquist dissented, along with Justices Antonin Scalia and Clarence Thomas. Rehnquist said that the majority relied too heavily on opinion polls in reaching its conclusion, and he was disdainful of any allusion to the lack of a death penalty in many other countries. "The viewpoints of other countries simply are not relevant," he said.

.Writing separately, Scalia said, "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." Scalia accused the majority of "thrashing about" in its search for a national consensus.

.O'Connor played a crucial role in the case, siding with the majority and reversing her stand of 13 years ago, when she wrote the last big decision on capital punishment and retarded defendants.

.Like many other cases that give rise to court rulings of profound importance, this one, Atkins v. Virginia, was born under horrible circumstances.

.Atkins, then 18, and a friend were seeking money to buy beer one night in the summer of 1996. They abducted a serviceman from Langley Air Force Base in Virginia, Eric Nesbitt, in the parking lot of a store, forced him to withdraw money from a teller machine, and then drove him to a deserted area. Ignoring his pleas for mercy, they shot him to death.

.At the trial, one psychiatrist called Atkins "mildly retarded."

.Atkins, convicted as the one who actually shot Nesbitt, was sentenced by the jury to death. The Virginia Supreme Court upheld the sentence last year and the case was argued before the U.S. Court on Feb. 21.

.Although Atkins's I.Q. has been measured at 59, Virginia has maintained that he is not in fact retarded, an issue that will have to be resolved in the state courts, now that the Supreme Court has ruled in his favor on the Eighth Amendment question. WASHINGTON In one of the most important capital punishment cases in years, the U.S. Supreme Court ruled Thursday that executing killers who are mentally retarded is unconstitutional.

.The 6-to-3 ruling not only spared the life of Daryl Atkins, a Virginia inmate, at least for now, but also could save scores of other death-row prisoners in the 20 states that still allow the execution of mentally retarded murderers. Thirty-eight of the 50 states have capital punishment.

.The ruling could also affect cases for years to come, as murder suspects of borderline intelligence argue through their lawyers that they should be classified as retarded and therefore should not face the death penalty.

.Mental health professionals generally regard those with an I.Q. below 70 as retarded. But the definitions used by medical professionals and those upon which judges and lawyers rely do not always coincide, especially in trying to determine a defendant's ability to know right from wrong and to assist in his own defense.

.Justice John Paul Stevens wrote the majority opinion, declaring that much has changed in the United States in the 13 years since the Supreme Court refused to recognize a constitutional bar to putting retarding people to death.

.In 1989, the court decided that "there is insufficient evidence of a national consensus" from which to conclude that such executions violated the country's "evolving standards of decency."

.But since then, "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," Stevens said.

.In fact, the number of states that have the death penalty but prohibit execution of the mentally retarded has grown to 18 today from 2 in 1989. That shift is powerful evidence that under the country's "evolving standards of decency" there is a growing consensus that executing retarded people is "cruel and unusual punishment" under the Eighth Amendment to the Constitution and that it therefore cannot be allowed, the majority held.

.Joining Stevens in the majority were Justices Sandra Day O'Connor, Anthony Kennedy, David Souter, Ruth Bader Ginsburg and Stephen Breyer.

.Chief Justice William Rehnquist dissented, along with Justices Antonin Scalia and Clarence Thomas. Rehnquist said that the majority relied too heavily on opinion polls in reaching its conclusion, and he was disdainful of any allusion to the lack of a death penalty in many other countries. "The viewpoints of other countries simply are not relevant," he said.

.Writing separately, Scalia said, "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." Scalia accused the majority of "thrashing about" in its search for a national consensus.

.O'Connor played a crucial role in the case, siding with the majority and reversing her stand of 13 years ago, when she wrote the last big decision on capital punishment and retarded defendants.

.Like many other cases that give rise to court rulings of profound importance, this one, Atkins v. Virginia, was born under horrible circumstances.

.Atkins, then 18, and a friend were seeking money to buy beer one night in the summer of 1996. They abducted a serviceman from Langley Air Force Base in Virginia, Eric Nesbitt, in the parking lot of a store, forced him to withdraw money from a teller machine, and then drove him to a deserted area. Ignoring his pleas for mercy, they shot him to death.

.At the trial, one psychiatrist called Atkins "mildly retarded."

.Atkins, convicted as the one who actually shot Nesbitt, was sentenced by the jury to death. The Virginia Supreme Court upheld the sentence last year and the case was argued before the U.S. Court on Feb. 21.

.Although Atkins's I.Q. has been measured at 59, Virginia has maintained that he is not in fact retarded, an issue that will have to be resolved in the state courts, now that the Supreme Court has ruled in his favor on the Eighth Amendment question. WASHINGTON In one of the most important capital punishment cases in years, the U.S. Supreme Court ruled Thursday that executing killers who are mentally retarded is unconstitutional.

.The 6-to-3 ruling not only spared the life of Daryl Atkins, a Virginia inmate, at least for now, but also could save scores of other death-row prisoners in the 20 states that still allow the execution of mentally retarded murderers. Thirty-eight of the 50 states have capital punishment.

.The ruling could also affect cases for years to come, as murder suspects of borderline intelligence argue through their lawyers that they should be classified as retarded and therefore should not face the death penalty.

.Mental health professionals generally regard those with an I.Q. below 70 as retarded. But the definitions used by medical professionals and those upon which judges and lawyers rely do not always coincide, especially in trying to determine a defendant's ability to know right from wrong and to assist in his own defense.

.Justice John Paul Stevens wrote the majority opinion, declaring that much has changed in the United States in the 13 years since the Supreme Court refused to recognize a constitutional bar to putting retarding people to death.

.In 1989, the court decided that "there is insufficient evidence of a national consensus" from which to conclude that such executions violated the country's "evolving standards of decency."

.But since then, "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," Stevens said.

.In fact, the number of states that have the death penalty but prohibit execution of the mentally retarded has grown to 18 today from 2 in 1989. That shift is powerful evidence that under the country's "evolving standards of decency" there is a growing consensus that executing retarded people is "cruel and unusual punishment" under the Eighth Amendment to the Constitution and that it therefore cannot be allowed, the majority held.

.Joining Stevens in the majority were Justices Sandra Day O'Connor, Anthony Kennedy, David Souter, Ruth Bader Ginsburg and Stephen Breyer.

.Chief Justice William Rehnquist dissented, along with Justices Antonin Scalia and Clarence Thomas. Rehnquist said that the majority relied too heavily on opinion polls in reaching its conclusion, and he was disdainful of any allusion to the lack of a death penalty in many other countries. "The viewpoints of other countries simply are not relevant," he said.

.Writing separately, Scalia said, "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." Scalia accused the majority of "thrashing about" in its search for a national consensus.

.O'Connor played a crucial role in the case, siding with the majority and reversing her stand of 13 years ago, when she wrote the last big decision on capital punishment and retarded defendants.

.Like many other cases that give rise to court rulings of profound importance, this one, Atkins v. Virginia, was born under horrible circumstances.

.Atkins, then 18, and a friend were seeking money to buy beer one night in the summer of 1996. They abducted a serviceman from Langley Air Force Base in Virginia, Eric Nesbitt, in the parking lot of a store, forced him to withdraw money from a teller machine, and then drove him to a deserted area. Ignoring his pleas for mercy, they shot him to death.

.At the trial, one psychiatrist called Atkins "mildly retarded."

.Atkins, convicted as the one who actually shot Nesbitt, was sentenced by the jury to death. The Virginia Supreme Court upheld the sentence last year and the case was argued before the U.S. Court on Feb. 21.

.Although Atkins's I.Q. has been measured at 59, Virginia hasWASHINGTON In one of the most important capital punishment cases in years, the U.S. Supreme Court ruled Thursday that executing killers who are mentally retarded is unconstitutional.

.The 6-to-3 ruling not only spared the life of Daryl Atkins, a Virginia inmate, at least for now, but also could save scores of other death-row prisoners in the 20 states that still allow the execution of mentally retarded murderers. Thirty-eight of the 50 states have capital punishment.

.The ruling could also affect cases for years to come, as murder suspects of borderline intelligence argue through their lawyers that they should be classified as retarded and therefore should not face the death penalty.

.Mental health professionals generally regard those with an I.Q. below 70 as retarded. But the definitions used by medical professionals and those upon which judges and lawyers rely do not always coincide, especially in trying to determine a defendant's ability to know right from wrong and to assist in his own defense.

.Justice John Paul Stevens wrote the majority opinion, declaring that much has changed in the United States in the 13 years since the Supreme Court refused to recognize a constitutional bar to putting retarding people to death.

.In 1989, the court decided that "there is insufficient evidence of a national consensus" from which to conclude that such executions violated the country's "evolving standards of decency."

.But since then, "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," Stevens said.

.In fact, the number of states that have the death penalty but prohibit execution of the mentally retarded has grown to 18 today from 2 in 1989. That shift is powerful evidence that under the country's "evolving standards of decency" there is a growing consensus that executing retarded people is "cruel and unusual punishment" under the Eighth Amendment to the Constitution and that it therefore cannot be allowed, the majority held.

.Joining Stevens in the majority were Justices Sandra Day O'Connor, Anthony Kennedy, David Souter, Ruth Bader Ginsburg and Stephen Breyer.

.Chief Justice William Rehnquist dissented, along with Justices Antonin Scalia and Clarence Thomas. Rehnquist said that the majority relied too heavily on opinion polls in reaching its conclusion, and he was disdainful of any allusion to the lack of a death penalty in many other countries. "The viewpoints of other countries simply are not relevant," he said.

.Writing separately, Scalia said, "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." Scalia accused the majority of "thrashing about" in its search for a national consensus.

.O'Connor played a crucial role in the case, siding with the majority and reversing her stand of 13 years ago, when she wrote the last big decision on capital punishment and retarded defendants.

.Like many other cases that give rise to court rulings of profound importance, this one, Atkins v. Virginia, was born under horrible circumstances.

Atkins, then 18, and a friend were seeking money to buy beer one night in the summer of 1996. They abducted a serviceman from Langley Air Force Base in Virginia, Eric Nesbitt, in the parking lot of a store, forced him to withdraw money from a teller machine, and then drove him to a deserted area. Ignoring his pleas for mercy, they shot him to death.

At the trial, one psychiatrist called Atkins "mildly retarded."

.Atkins, convicted as the one who actually shot Nesbitt, was sentenced by the jury to death. The Virginia Supreme Court upheld the sentence last year and the case was argued before the U.S. Court on Feb. 21.

.Although Atkins's I.Q. has been measured at 59, Virginia has maintained that he is not in fact retarded, an issue that will have to be resolved in the state courts, now that the Supreme Court has ruled in his favor on the Eighth Amendment question.