LEGAL DECISION

Legal Decision



Legal Decision

Supreme Court decisions in Cowan v Montana & Shannon v United States.

The insanity defense is based on the centuries-old principle that a person ought not to be punished for wrongdoing unless criminal intent can be established. A person using the defense seeks to be acquitted of a crime by reason of insanity. In the past, it seems, judges knew a "lunatic" when they saw one, and when a person was acquitted of a crime by reason of insanity, he might expect to spend years or a lifetime locked up in an institution for the criminally insane. Today, advances in psychiatric treatment and concern for the rights of the mentally ill have changed the way the legal system deals with insanity ("insane" is a legal term, not a medical diagnosis). In this panel we look at some landmark court decisions regarding the use of the insanity defense. The next panel looks at popular perceptions of this defense.

Court Cases Establish Precedents: The modern insanity defense, incorporating the concepts of "knowing right from wrong" and "temporary insanity" was inscribed in Western law books in 1843 when a British court found Daniel M'Naghten (a k a McNaughtan) not guilty by reason of insanity (NGRI) of trying to assassinate the prime minister. The defense became so popular in America that Mark Twain complained: "This country, during the last thirty or forty years, has produced some of the most remarkable cases of insanity of which there is any mention in history.… Is not this insanity plea becoming rather common?"

The M'Naghten Rule was the standard used in American courtrooms until 1962, but not everyone was happy with it. Long before 1962, some complained that the rule excused only the most profoundly mentally ill from criminal conduct. Shouldn't there be some consideration for the person who couldn't stop himself, even though he knew an act was wrong? In 1886 there appeared the first of a series of court decisions establishing new criteria for the insanity defense — Parsons v Alabama; it added the concept of "irresistible impulse."11 In 1962 the American Law Institute (A.L.I.) proposed a new standard; at least half of the states use the standard now.12 Among other things, the A.L.I. test recognized that there are varying degrees of incapacity.

Meanwhile, the field of psychiatry emerged with new theories, definitions, and treatments for the mentally ill. In 1954 the U.S. Supreme Court ruled in Durham v United States that a person could not be held criminally responsible if his act was the "product of a mental disease or defect." This decision eliminated any consideration of right and wrong from the insanity defense and is credited with bringing legions of psychiatrists into courtrooms to expound on the meaning of "product" and "mental disease" and "defect" and so on.

Public Perceptions: As the legal establishment struggled to clarify the appropriate use and interpretation of the insanity defense, the public seemed to think that the defense was being used too often and ...