This entry contains information applicable to United States law only. A defense asserted by an accused in a criminal prosecution to avoid liability for the commission of a crime because, at the time of the crime, the person did not appreciate the nature or quality or wrongfulness of the acts.
The insanity defense is used by criminal defendants. The most common variation is cognitive insanity. Under the test for cognitive insanity, a defendant must have been so impaired by a mental disease or defect at the time of the act that he or she did not know the nature or quality of the act, or, if the defendant did know the nature or quality of the act, he or she did not know that the act was wrong. The vast majority of states allow criminal defendants to invoke the cognitive insanity defense.
Another form of the insanity defense is volitional insanity, or irresistible impulse. Irresistible impulse asserts that the defendant, though able to distinguish right from wrong at the time of the act, suffered from a mental disease or defect that made the defendant incapable of controlling her or his actions. This defense is common in crimes of vengeance. For example, assume that a child has been brutally assaulted. If an otherwise conscientious and law-abiding mother shoots the perpetrator, the mother may argue that she was so enraged that she became mentally ill and incapable of exerting self-control. Approximately five states allow the volitional insanity defense.
The insanity defense should not be confused with incompetency. Persons who are incompetent to stand trial are held in a mental institution until they are considered capable of participating in the proceedings.
The insanity defense should also be kept separate from issues concerning mental retardation. Mentally retarded persons, or persons with an IQ of seventy or lower, may be convicted and even sentenced to death if they are found competent to stand trial.
The insanity defense reflects the generally accepted notion that persons who cannot appreciate the consequences of their actions should not be punished for criminal acts. Most states regulate the defense with statutes, but a few states allow the courts to craft the rules for its proper use. Generally, the defense is available to a criminal defendant if the judge instructs the jury that it may consider whether the defendant was insane when the crime was committed. The judge may issue this instruction if the defendant has produced sufficient evidence at trial to justify the theory. Sufficient evidence invariably includes expert testimony by psychologists and psychiatrists.
When invoking insanity as a defense, a defendant is required to notify the prosecution. In some states, sanity is determined by the judge or jury in a separate proceeding following the determination of guilt or innocence at trial. In other states, the defense is either accepted or rejected in the verdict of the judge or jury. Even if evidence of insanity does not win a verdict of not guilty, the sentencing court may consider it as a mitigating factor.
History
"Complete madness" was first established as a defense to criminal charges by the common-law courts in late-thirteenth-century England. By the eighteenth century, the complete madness definition had evolved into the "wild beast" test. Under this test, the insanity defense was available to a person who was "totally deprived of his understanding and memory so as not to know what he [was] doing, no more than an infant, a brute, or a wild beast" (Feigl 1995, 161).
By 1840, most jurisdictions had refined the wild beast test to cognitive insanity and supplemented that with irresistible impulse insanity. However, in 1843, a well-publicized assassination attempt in England caused Parliament to eliminate the irresistible impulse defense. Daniel M'Naghten, operating under the delusion that Prime Minister Robert Peel wanted to kill him, endeavored to shoot Peel but shot and killed Peel's secretary instead. Medical testimony indicated that M'Naghten was psychotic, and the court acquitted him by reason of insanity (M'Naghten's Case, 8 Eng. Rep. 718 [1843]). In response to a public furor that followed the decision, the House of Lords ordered the Lords of Justice of the Queen's Bench to craft a new rule for insanity in the criminal law.
What emerged became known as the M'Naghten rule. This rule migrated to the United States within a decade of its conception, and it stood for the better part of the next century. The intent of the M'Naghten rule was to abolish the irresistible impulse defense and limit the insanity defense to cognitive insanity. Under the M'Naghten rule, insanity was a defense if
at the time of the committing of the act, the party accused was labouring under such a defect of reason, from a disease of the mind, as not to know the nature and quality of the act he was doing; or, if he did know it, that he did not know he was doing what was wrong.
Through the first half of the twentieth century, the insanity defense was expanded again. Courts began to accept the theories of psychoanalysts, many of whom encouraged recognition of the irresistible impulse defense. Many states enacted a combination of the M'Naghten rule supplemented with an irresistible impulse defense, thereby covering both cognitive and volitional insanity.
The insanity defense reached its most permissive standard in Durham v. United States, 214 F.2d 862 (D.C. Cir. 1954). The Durham rule excused a defendant "if his unlawful act was the product of mental disease or mental defect." The Durham rule was lauded by the mental health community as progressive because it allowed psychologists and psychiatrists to contribute to the judicial understanding of insanity. But it was also criticized for placing too much trust in the opinions of mental health professionals. Within seven years of its creation, the rule had been explicitly rejected in twenty-two states. It is used only in New Hampshire.
In 1964, the American Law Institute (ALI) began to reassess the insanity defense in the course of promoting a new Model Penal Code. What emerged from the Model Penal Code Commission was a compromise between the narrow M'Naghten test and the generous Durham rule. The ALI test provided that a person was not responsible for criminal conduct if, at the time of the act, the person lacked "substantial capacity" to appreciate the conduct or to conform the conduct to the rule of law. The ALI test provided for both cognitive and volitional insanity. It also required only a lack of substantial capacity, less than complete impairment. The ALI version of the insanity defense was adopted by more than half the states and all but one federal circuit.
Several years later, another dramatic event led to another round of restrictions on the insanity defense. In 1981, John Hinckley, Jr., attempted to assassinate President Ronald Reagan. Hinckley was prosecuted and acquitted of all charges by reason of insanity, and a resulting public outcry prompted Congress to enact legislation on the issue. In 1984, Congress passed the Insanity Defense Reform Act (Insanity Act) (18 U.S.C.A. § 17 [1988]) to abolish the irresistible impulse test from federal courts. Initially, Reagan had called for a total abolition of mental illness as a defense to criminal charges, but the Reagan administration backed down from this position after intense lobbying by various professional organizations and trade associations.
The Insanity Act also placed the burden on the defendant to prove insanity. Before the Insanity Act, federal prosecutors bore the burden of proving the defendant's sanity beyond a reasonable doubt.
Most states joined Congress in reevaluating the insanity defense after Hinckley's acquittal. The legislatures of these states modified and limited the insanity defense in many and varied ways. Some states shifted the burden of proof, and some limited the applicability of the defense in the same manner as Congress did. A few states abolished the defense entirely. Chief Justice William H. Rehnquist, of the Supreme Court, opined in a dissent that it is "highly doubtful that due process requires a State to make available an insanity defense to a criminal defendant" (Ake v. Oklahoma, 470 U.S. 68, 105 S. Ct. 1087, 84 L. Ed. 2d 53 [1985]).
Consequences
When a party successfully defends criminal charges on a ground of insanity, the consequences vary from jurisdiction to jurisdiction. Usually, the defendant is committed to a mental institution. On the average, a defendant found not guilty by reason of insanity and committed to a mental institution is confined twice as long as a defendant found guilty and sent to prison. Very few acquitted insanity defendants are given supervised release, and even fewer are released directly following their verdict.
The detention of an insanity acquittee is limited by law. The acquittee must be allowed periodic review in the mental institution to determine whether continued treatment is necessary. In addition, a hospital facility may not hold an insanity acquittee indefinitely merely because the acquittee has an antisocial personality (Foucha v. Louisiana, 504 U.S. 71, 112 S. Ct. 1780, 118 L. Ed. 2d 437 [1992]).
The procedural framework in Massachusetts illustrates the consequences that come with the insanity defense. Under chapter 123, section 16, of the Massachusetts General Laws Annotated, the court may order a person found not guilty by reason of insanity (an insanity acquittee) to be hospitalized for forty days for observation and examination. During this period, the district attorney or the superintendent of the mental hospital may petition the court to have the insanity acquittee committed to the hospital. If the judge orders the commitment, the acquittee is placed in the hospital for six months.
After the first six months have expired, the commitment is reviewed again, and then once a year thereafter. If the superintendent of the mental health facility moves to discharge the acquittee, the district attorney must respond with any objections within thirty days of notice from the superintendent. The mental health facility is authorized to restrict the movement of criminal defendants and insanity acquittees, so a commitment is tantamount to incarceration.
Defendants' Rights
When pleading insanity, a defendant may not want to present the best possible image at trial. In Riggins v. Nevada, 504 U.S. 127, 112 S. Ct. 1810, 118 L. Ed. 2d 479 (1992), defendant David Riggins was charged with robbing and murdering Las Vegas resident Paul Wade. After being taken into custody, Riggins complained that he was hearing voices in his head and was having trouble sleeping. A psychiatrist at the jail prescribed 100 milligrams a day of Mellaril, an antipsychotic drug. By the time of trial, the psychiatrist was prescribing 800 milligrams a day of Mellaril.
Just before trial, Riggins's attorney moved the court to suspend administration of the Mellaril. Riggins was pleading not guilty by reason of insanity, and Riggins's attorney wanted the jury to see Riggins in his natural state. According to one psychiatrist, Dr. Jack Jurasky, Riggins "would most likely regress to a manifest psychosis and become extremely difficult to manage" if he were taken off Mellaril.
The court denied the motion, and Riggins was convicted and sentenced to death. The Nevada Supreme Court affirmed Riggins's convictions and death sentence. On appeal to the U.S. Supreme Court, the convictions were reversed. According to the High Court, Nevada had violated Riggins's due process rights under the Sixth and Fourteenth Amendments. In the absence of evidence that the treatment was medically appropriate and essential for Riggins's own safety or the safety of others, and without an exploration of less intrusive alternatives, the trial court had erred by denying Riggins's liberty interest in freedom from antipsychotic drugs.
According to the High Court, the administration of the Mellaril jeopardized a number of Riggins's trial rights. Not only was it possible that the Mellaril had affected Riggins's outward appearance, and thus his defense, but the high daily dosage of Mellaril may also have affected Riggins's testimony, his ability to communicate with his attorney, and his ability to follow the proceedings. Although the defense had been allowed to present expert testimony on the nature of Riggins's mental condition, the Court concluded that the compromise of Riggins's trial rights was unacceptable.
Uses and Abuses
Victims of abuse often allege temporary insanity in defending their own violent behavior. For example, in 1994, Virginia resident Lorena Bobbitt, charged with severing her husband's penis with a knife, was acquitted of assault charges on the ground of temporary insanity. At trial, Bobbitt testified that her husband had abused her physically and emotionally.
Critics complain that the insanity defense is abused by defense attorneys, who use it to free the perpetrators of deliberate criminal acts. However, 95 percent of all persons found not guilty by reason of insanity are detained in hospitals, and in practice, the insanity defense is rarely invoked and rarely successful. The insanity defense is used by defendants in only one percent of all felony cases, and it results in acquittal in only one-quarter of those cases.
