Insanity defense

Psychiatric treatment
Those found to have been not guilty by reason of insanity are generally then required to undergo psychiatric treatment; except in the case of temporary insanity (see below). Defendants found not guilty by reason of insanity are generally placed in a mental institution. Unlike defendants who are found guilty of a crime, they are not institutionalized for a fixed period, but rather they are held within the institution until authorities determine that they are no longer a threat. Authorities making this decision tend to be cautious; as a result, defendants can often spend more time there than they would have in prison (had they been convicted). In Foucha v. Louisiana (1992) the Supreme Court ruled that a person could not be held "indefinitely".

Psychosis and schizophrenia
In practice, a finding of "not guilty by reason of insanity" almost always requires that the defendant have been in a state of active psychosis (at the time the law was broken) and usually such findings involve a diagnosis of paranoid schizophrenia. The use of the insanity defense in cases of psychopathy is rare and almost uniformly unsuccessful.

Incompetency, intoxication, and mental illness
The concept of insanity is different from the concept of incompetency. Incompetency denotes the inability of a defendant to understand the charges against them, to participate in their defense, and relates to the defendant's state of mind at the time of trial. A trial cannot proceed if a defendant has been found incompetent, unless the defendant later becomes competent.

In the United States. a trial in which the insanity defense is invoked typically involves the testimony of psychiatrists which argue that the defendant is or is not insane. If there is agreement between the prosecution and defense that the defendant is insane then typically a jury trial is waived and a trial occurs in front of a judge in which evidence is presented and a judgment rendered. If there is disagreement between the prosecution and defense, each will typically present expert witnesses to a jury which will decide whose witnesses to believe.

The legal concept of insanity is different from the psychiatric concept of mental illness. Frequently, a person whose mental illness is not under dispute will be determined sane as the court will argue that despite a "mental illness" the defendant should still be held responsible; such a ruling is known as either a Guilty but Mentally Ill (GBMI) or a Guilty but Insane verdict. Michigan (1975) was the first state to pass a GBMI verdict. Sometimes a person without mental illness to be found to be insane, as for example, if a person who is acting under the influence of a drug that was involuntarily administered (though voluntary intoxication has been rejected by most jurisdictions as a defence to crime). (See: involuntary intoxication)

History of the insanity defense
The concept of defense by insanity has existed since ancient Greece and Rome. The first complete transcript of an insanity trial dates 1724. In Ford v. Wainwright (1975) the US Supreme Court ruled that insane prisoners cannot be executed.

One novel use of the insanity defense occurred in the case of Lee Boyd Malvo who plead not guilty by reason of insanity in the Beltway sniper shootings. Many legal experts believe that the purpose of raising the defense was not to gain an accquital but to allow the defense to introduce otherwise inadmmissble evidence about Malvo's upbringing, his relationship with John Walker Muhammed, and his mental state. This evidence was intended to gain the jury's sympathy so that they would not invoke the death penalty, and was successful at doing so.

Controversy Over the insanity defense
There are many different interpretations of "insane" and many different notions of how to deal with insane individuals.

In the US (1982), the insanity defense came under increasing criticism following the acquittal of John Hinckley, Jr., who attempted to assassinate President Reagan. Critics of the defense argue that it relies too much on opinion and/or "permits" behavior by one group which is forbidden to another.

Some opponents of the insanity defense, including Thomas Szasz, believe that psychiatry itself emerged as a way to justify mercy, of making persons "exceptional" and thus not deserving of the harsh punishment we would as a society wish to dole out to people who had extremely selfish or widely shared rationales for their actions. Since extreme selfishness ("self-absorption") or broadly shared resentments (e.g. envy of the rich, hatred of another ethnic group) are somewhat infectious behaviors, some argue that schizophrenia and other "mental illness" were defined into existence to protect those whose motives and behaviors were not so infectious, and whose offenses were thus unlikely to be repeated by others. The cost of this system of mercy, however, was to classify the psychiatrist and patient in an ongoing unequal-power relationship. See myth of mental illness and antipsychiatry).

However, the main criticism was, and is, largely uninformed - it is not of defining insanity, but that people are "getting away" with a crime.

The insanity defense is not commonly used. In the United States, the insanity defense was used in less than 2% of all capital cases and was unsuccessful in almost 80% of the trials. Polls however indicate that the public believes that the defense is used and is successful far more often than is the case, and most legal experts attribute this to the fact that cases involving the insanity defense tend to be high profile ones.

Some US courts have begun to ban the use of the insanity defense and a 1994 Supreme Court ruling upheld the right of Montana to do so. Idaho and Utah have also banned this defense.

The McNaghten rules
The McNaghten rules (England and Wales, 1843) state that a person "...is not guilty of a crime if, at the time of the crime, they either didn't know what they were doing, or didn't know that what they were doing was wrong." This rule was later adopted within the US.

The irresistible impulse
There is also an idea of an irresistible impulse, which argues that a person may have known an act was illegal; but, because of a mental impairment, they couldn't control their actions. In 1994, Lorena Bobbitt was found not guilty of a crime, when her defense argued that an irresistible impulse led her to cut off her husband's penis.

The Durham rule
The Durham Rule (1954) states that "... an accused is not criminally responsible if his unlawful act was the product of mental disease or defect". After the 1970s, US jurisdictions have tended to not recognize this argument as it places emphasis on "mental disease or defect" and thus on testimony by psychiatrists and is argued to be somewhat ambigious.

The Insanity Defense Reform Act
The Insanity Defense Reform Act (US - 1984) states that insanity is a "severe mental disease or defect...[which causes a defendant to be] unable to appreciate the nature and quality or the wrongfulness of [their] acts."

The Substantial Capacity Test
The Substantial Capacity Test was defined by the American Law Institute, in its Model Penal Code: Official Draft and Explanatory Notes. This argues that insanity should be defined as a lack of substantial capacity to control one's behavior. Substantial capacity is defined as: "the mental capacity needed to understand the wrongfulness of [an] act, or to conform...behavior to the...law." This is related to the McNaghten Rule and the idea of 'irresistible impulse'.

The Brawner rule
The Brawner Rule (1972) argues that insanity should be decided by a jury. Under this proposal, juries are allowed to decide the "insanity question" as they see fit.

Temporary insanity
The notion of temporary insanity argues that a defendant was insane, but is now sane. A defendant found to have been temporarily insane will often be released without any requirements of psychiatric treatment. This defense was first used by U.S. Congressman Daniel Sickles of New York in 1859 after he had killed his wife's lover, Philip Barton Key, but was most used during the 1940s and 1950s. Since then, however, it has been becoming less successful.