Penry v. Lynaugh --U.S.--, 109 S.Ct. 2934 (1989).
The United States Supreme Court has ruled that mentally retarded criminal offenders may be sentenced to death, but only if the sentencing jury has been permitted to consider and give effect to evidence of mental retardation offered by the defense in mitigation of penalty. Because the instructions under which Penry was sentenced to death provided no opportunity for the jury to take into account Penry's evidence in mitigation, Justice Sandra Day O'Connor concluded, they were defective. Penry's sentence was vacated for violation of the eighth amendment's prohibition of cruel and unusual punishment.
The defendant in this case, Johnny Penry, was charged with capital murder in the rape-killing of a woman in Texas. An evaluation of Penry's competency to stand trial revealed that he was mildly to moderately retarded, with an I.Q. of 54 and a mental age of 6 1/2 years. Nonetheless, he was found competent to stand trial.
At his trial, Penry raised the defense of insanity and presented the testimony of a psychiatrist, Dr. Jose Garcia. Dr. Garcia testified that Penry suffered from organic brain damage and moderate mental retardation, which impaired his impulse control and rendered him unable to learn from experience. Dr. Garcia testified further that, because of his disability, Penry was unable to appreciate the wrongfulness of his conduct or conform his conduct to the requirements of the law. The prosecution presented two psychiatrists who testified that although Penry was a person of extremely limited mental ability and seemed unable to learn from his mistakes, nonetheless he was sane under Texas law. Moreover, these psychiatrists diagnosed a coexisting antisocial personality disorder. The jury convicted Penry of capital murder.
At Penry's sentencing hearing, the judge instructed the jury to answer three "special issues": (1) whether the killing was deliberate, (2) whether Penry was dangerous, and (3) whether the killing was unreasonable in response to the provocation, if any, of the victim. If the jury's response to each issue was "yes," the sentence was to be death; otherwise, Penry would be sentenced to life in prison. Penry's attorney objected to these instructions, arguing, first, that the jury should not be permitted to impose the death penalty in light of Penry's mental retardation and, second, that, even if Penry's mental retardation were no absolute bar to a sentence of death, the judge's instructions were defective because they provided no opportunity for the jury to take into account ("give effect to") Penry's evidence in mitigation. These and other defense objections were overruled, the jury unanimously responded in the affirmative to all three special issues, and Penry was sentenced to death.
The Texas Court of Criminal Appeals affirmed Penry's conviction and sentence, and both a federal district court and the United States Court of Appeals for the Fifth Circuit rejected Penry's habeas corpus claim. The United States Supreme Court agreed to review the case to answer two questions: (1) whether the jury instructions afforded the jury an adequate opportunity to consider and give effect to Penry's evidence in mitigation, and (2) whether the death penalty may be imposed on a mentally retarded person with Penry's reasoning ability.
Addressing the first of these questions in her opinion for the Court, Justice O'Connor cited a line of prior Supreme Court decisions holding that "punishment should be directly related to the personal culpability of the criminal defendant."
"[E]vidence about the defendant's background and character is relevant because of the belief, long held by society, that defendants who commit criminal acts that are attributable to a disadvantaged background, or to emotional and mental problems, may be less culpable than defendants who have no such excuse." [Quoting from California v. Brown 479 U. …