incapable of distinguishing right from wrong

Late in 1979, Glen Burton Ake was arrested and charged with murdering a couple and wounding their two children. He was arraigned in the District Court for Canadian County, Oklahoma, in February 1980. His behavior at arraignment and in other prearraignment incidents at the jail was so bizarre that the trial judge, sua sponte, ordered him to be examined by a psychiatrist for the purpose of advising with the Court as to his impressions of whether the Defendant may need an extended period of mental observation. The examining psychiatrist reported that at times Ake appeared to be frankly delusional and claimed to be the sword of vengeance of the Lord. He diagnosed Ake as a probable paranoid schizophrenic and recommended a prolonged psychiatric evaluation to determine whether Ake was competent to stand trial. In March 1980, Ake was committed to a state hospital to be examined with respect to his present sanity. On April 10, the chief forensic psychiatrist informed the court that Ake was not competent to stand trial. The court held a competency hearing at which a psychiatrist testified that Ake was a psychotic with a diagnosis of paranoid schizophrenia chronic with exacerbation, that he was dangerous, and that he required a maximum security facility. The court found Ake to be a mentally ill person in need of care and treatment and incompetent to stand trial, and ordered him committed to the state mental hospital. Six weeks later, the chief forensic psychiatrist informed the court that Ake had become competent to stand trial while receiving 200 milligrams of Thorazine three times daily. At a pretrial conference in June, Ake's attorney informed the court that his client would raise an insanity defense. Counsel requested that a psychiatrist examine Ake with respect to his mental condition at the time of the offense or that the court provide funds for such an examination. The trial judge denied the motion. Ake was tried for two counts of murder in the first degree and two counts of shooting with intent to kill. At the guilt phase, defense counsel called the psychiatrists who had examined Ake at the state hospital, but none testified about his mental state at the time of the offense. The jury rejected the insanity defense and returned a verdict of guilty on all counts. At the sentencing proceeding, the prosecutor relied on the testimony of the state psychiatrists that Ake was dangerous to society. Ake had no expert witness to rebut this testimony or to introduce evidence in mitigation. The jury sentenced Ake to death on each of the two murder counts and to 500 years' imprisonment on each of the two counts of shooting with intent to kill. On appeal, the Oklahoma Court of Criminal Appeals affirmed the convictions and sentences. The Supreme Court granted certiorari.

Dennis Davis was indicted for the crime of having, on the 18th day of September, 1894, at the Creek Nation, in the Indian Territory, within the Western District of Arkansas, feloniously, wilfully, and of his malice aforethought, killed and murdered one Sol Blackwell. He was found guilty of the charge in the indictment. A motion for a new trial having been overruled, and the court having adjudged that the accused was guilty of the crime of murder, as charged, he was sentenced to suffer the penalty of death by hanging. At the trial below the government introduced evidence which, if alone considered, made it the duty of the jury to return a verdict of guilty of the crime charged. But there was evidence tending to show that at the time of the killing the accused, by reason of unsoundness or weakness of mind, was not criminally responsible for his acts. In addition to the evidence of a practicing physician of many years standing, and who, for the time, was physician at the jail in which the accused was confined previous to his trial, other witnesses testified that they had been intimately acquainted with the defendant for several years, lived near him, and had been frequently with him, knew his mental condition, and that he was weak-minded, and regarded by his neighbors and people as being what they called half crazy. Other witnesses who had known the defendant for ten to twenty years, witnesses who had worked with him and had been thrown in constant contact with him, said he had always been called half crazy, weak-minded; and in the opinion of the witnesses defendant was not of sound mind.

In 1994, the Kansas Legislature enacted the Sexually Violent Predator Act, which established procedures for the civil commitment of persons who, due to a mental abnormality or personality disorder, are likely to engage in predatory acts of sexual violence. Leroy Hendricks had a long history of sexually molesting children, beginning with a 1955 conviction for indecent exposure, followed by convictions for lewdness involving a young girl in 1957, molesting two young boys in 1960, indecent liberties with a child in 1965, and taking indecent liberties with two 13-year-old boys in both 1984 and 1994. As Hendricks neared the end of his prison term in 1994, the State filed a petition in state court seeking to have him committed under the Act. Hendricks challenged the constitutionality of the Act but did not contest that he met the statutory definition of a sexually violent predator. At trial, Hendricks testified that he suffers from pedophilia, that he is not cured, and that when he gets stressed out he cannot control the urge to molest children. The jury unanimously found beyond a reasonable doubt that Hendricks was a sexually violent predator. The trial court determined that the Act was constitutional and ordered him committed to the custody of the Secretary of Social and Rehabilitation Services. The Kansas Supreme Court reversed the commitment order. It held that the Act violated Hendricks’ substantive due process rights because it did not require a finding that he was unable to control his violent behavior. The court did not address the Act’s procedural due process or double jeopardy claims. The State of Kansas petitioned for certiorari, and Hendricks filed a cross-petition reasserting his federal double jeopardy and ex post facto claims. The United States Supreme Court granted certiorari on both the petition and the cross-petition.

On the morning of October 25, 1979, Pamela Carpenter was brutally raped, beaten, and stabbed with a pair of scissors in her home in Livingston, Texas. She died a few hours later in the course of emergency treatment. Before she died, she described her assailant. Her description led two local sheriff's deputies to suspect Penry, who had recently been released on parole after conviction on another rape charge. Penry subsequently gave two statements confessing to the crime and was charged with capital murder. At a competency hearing held before trial, a clinical psychologist, Dr. Jerome Brown, testified that Penry was mentally retarded. As a child, Penry was diagnosed as having organic brain damage, which was probably caused by trauma to the brain at birth. Penry was tested over the years as having an IQ between 50 and 63, which indicates mild to moderate retardation. Dr. Brown's own testing before the trial indicated that Penry had an IQ of 54. Dr. Brown's evaluation also revealed that Penry, who was 22 years old at the time of the crime, had the mental age of a 6 1/2-year-old. Penry's social maturity, or ability to function in the world, was that of a 9- or 10-year-old. The guilt-innocence phase of the trial began on March 24, 1980. At trial, Penry raised an insanity defense and presented the testimony of a psychiatrist, Dr. Jose Garcia. Dr. Garcia testified that Penry suffered from organic brain damage and moderate retardation, which resulted in poor impulse control and an inability to learn from experience. Penry's mother testified at trial that Penry was unable to learn in school and never finished the first grade. Penry's sister testified that their mother had frequently beaten him over the head with a belt when he was a child. Penry was also routinely locked in his room without access to a toilet for long periods of time. The State introduced the testimony of two psychiatrists to rebut the testimony of Dr. Garcia. Dr. Kenneth Vogtsberger testified that although Penry was a person of limited mental ability, he was not suffering from any mental illness or defect at the time of the crime, and that he knew the difference between right and wrong and had the potential to honor the law. Dr. Felix Peebles also testified for the State that Penry was legally sane at the time of the offense and had a full-blown anti-social personality. The jury rejected Penry's insanity defense and found him guilty of capital murder. The following day, at the close of the penalty hearing, the jury decided the sentence to be imposed on Penry by answering three special issues. Defense counsel raised objections to the proposed charge to the jury, including that the charge failed to define the term "deliberately" and failed to authorize a discretionary grant of mercy based upon the existence of mitigating circumstances and that, in light of Penry's mental retardation, permitting the jury to assess the death penalty in this case amounted to cruel and unusual punishment prohibited by the Eighth Amendment. The jury answered yes to all three special issues, and Penry was sentenced to death. The Texas Court of Criminal Appeals affirmed his conviction and sentence on direct appeal. This Court denied certiorari on direct review. Penry then filed this federal habeas corpus petition challenging his death sentence. Among other claims, Penry argued that he was sentenced in violation of the Eighth Amendment because the trial court failed to instruct the jury on how to weigh mitigating factors in answering the special issues. The District Court denied relief, and Penry appealed to the Court of Appeals for the Fifth Circuit. The Court of Appeals affirmed the District Court's judgment. The Supreme Court granted certiorari to resolve two questions.