Also known as: mental disease or defect · mental disease · mental defect · insanity defense · lack of criminal responsibility
Written by attorneys — see sources below.
An affirmative defense to criminal liability that excuses a defendant from responsibility for conduct when, as a result of mental disease or defect, the defendant lacked substantial capacity either to appreciate the criminality or wrongfulness of the conduct or to conform the conduct to the requirements of law. The defense does not encompass an abnormality manifested only by repeated criminal or antisocial conduct.
Maurice Marshall, diagnosed with severe schizophrenia, deliberately set fire to a vacant warehouse after weeks of delusional beliefs that the building housed government surveillance equipment. Medical records confirmed that the delusions directly drove the arson. The court acquitted Marshall because the offense would not have occurred but for his mental disease.
Mariam Mansour remained silent after receiving Miranda warnings when asked about prior mental health treatment. At trial she raised an insanity defense based on bipolar disorder. The prosecutor attempted to use her silence to argue the defense was fabricated, but the court sustained the objection and barred the argument.
Miranda Morales faced capital murder charges after killing her roommate during a psychotic episode. Her defense introduced expert testimony that bipolar disorder substantially impaired her capacity to appreciate wrongfulness. The jury considered the evidence and imposed life imprisonment rather than death.
Meredith Maxwell was indicted for embezzlement and waited until after discovery closed to file written notice of an insanity defense. She cited recent hospitalization but offered no explanation why the records could not have been obtained earlier. The court denied leave to file late and precluded the defense at trial.
Musa Mensah was acquitted of assault after proving that schizophrenia caused him to attack a stranger he believed was an alien. The court immediately ordered commitment to a state mental health facility for custody, care, and treatment rather than release.
Michelle Murphy, an indigent defendant charged with murder, made a preliminary showing that she would rely on an insanity defense. The court ordered the state to provide access to a psychiatrist to assist in preparing the defense and to testify at sentencing regarding future dangerousness.
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.
The defendant must prove that at the time of the conduct, as a result of mental disease or defect, the defendant lacked substantial capacity either to appreciate the criminality or wrongfulness of the conduct or to conform the conduct to the requirements of law. The defense excludes abnormalities shown only by repeated criminal or antisocial conduct.
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…or would gravely impair the physical or mental health of the mother, (ii) that the child would be born with grave physical or mental defect, or (iii) that the pregnancy resulted from rape or incest, or illicit intercourse with a girl under the age of 16 years]. "SECTION 2. [ Penalty. ] Any person who performs or procures an…
…was ratified. Commonwealth v. York , 50 Mass. 93 (1845). In 1895 the common-law view was abandoned with respect to the insanity defense in federal prosecutions. Davis v. United States , 160 U. S. 469 (1895). This ruling had wide impact on the practice in the federal courts with respect to the burden of proving various…
…either so deficient that he has no will, no conscience, of controlling mental power, or if, through the overwhelming violence of mental disease, his intellectual power is for the time obliterated, he is not a responsible moral agent, and is not punishable for criminal acts." Commonwealth v. Rogers, 7 Met. (Mass.) 500. Neither in…
…Majority opinion · : The statute provides: : Petitioner initially filed a notice of intent to rely on "mental disease or defect excluding criminal responsibility" as a defense. That defense required evidence that defendant was "unable either to appreciate the criminality of his conduct or to conform his conduct to…
…proceedings against Ake. At a pretrial conference in June, Ake’s attorney informed the court that his client would raise an insanity defense. To enable him to prepare and present such a defense adequately, the attorney stated, a psychiatrist would have to examine Ake with respect to his mental condition at the time of the…
A defendant must notify the government in writing within the time for filing pretrial motions or at a later time set by the court. Failure to provide timely notice bars reliance on the defense unless the court finds good cause for a late filing.
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The court must order the defendant committed to the custody of the Commissioner of Mental Hygiene for placement in an appropriate institution for custody, care, and treatment. Release requires a later judicial determination that the person poses no danger to self or others.
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No. Once Miranda warnings are given, the government implicitly assures the suspect that silence carries no penalty. Using post-warning silence as evidence to undermine an insanity claim violates due process.
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Yes. When a jury or court may recommend death or imprisonment, evidence that mental disease or defect impaired the defendant's capacity to appreciate wrongfulness or conform conduct to law is admissible in favor of a sentence of imprisonment.
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