Insanity Defense


insanity, mental disorder of such severity as to render its victim incapable of managing his affairs or of conforming to social standards. Today, the term insanity is used chiefly in criminal law, to denote mental aberrations or defects that may relieve a person from the legal consequences of his or her acts. The case of Daniel McNaughtan, who was found not guilty by reason of insanity after making an assassination attempt on British prime minister Robert Peel (1834), gave rise to the modern insanity defense used in many Western nations today. In the United States, the 1954 case of Durham v. the United States led to the establishment of new rules for testing defendants. Today, psychologists may perform tests to determine whether or not the defendant is mentally stable. Such tests try to ascertain whether or not a defendant can distinguish right from wrong, and whether or not he acted on an "irresistible impulse." John Hinckley's assassination attempt on Ronald Reagan (1981) became another landmark in the history of the insanity defense. The court's initial verdict of "not guilty by reason of insanity" generated public outcry and renewed interest in the verdict of "guilty but mentally ill," which is permissible in some states. This verdict allows defendants deemed mentally ill to be hospitalized but requires them to carry out a reasonable prison sentence as well. In 1983, the Supreme Court ruled it permissable to keep a mentally ill defendant hospitalized for a term longer than the maximum sentence for the crime with which the defendant was charged. Many have contended that the insanity defense is nothing more than a legal loophole, allowing serious criminals to escape imprisonment. In fact, the plea is rarely employed in the United States, and it is estimated that less than 1% of defendants have used it successfully. Recent years have seen the restrictions surrounding insanity defense considerably narrowed, with the sole criteria for a successful plea being the determination of whether or not the defendant knew he was breaking the law.

See R. Simon and D. Aaronson, The Insanity Defense (1988); R. Porter, A Social History of Madness: The World Through the Eyes of the Insane (1989).

The Columbia Encyclopedia, 6th ed. Copyright© 2014, The Columbia University Press.

Insanity Defense: Selected full-text books and articles

Evil or Ill? Justifying the Insanity Defence
Lawrie Reznek.
Routledge, 1997
Offenders, Deviants or Patients?
Herschel Prins.
Routledge, 2005 (3rd edition)
Librarian’s tip: Especially Chap. 1 "Not in Their Right Minds"
Crime and Punishment in American History
Lawrence M. Friedman.
BasicBooks, 1993
Librarian’s tip: "The Insanity Defence" starts on p. 401
'My Brain Made Me Do It'-How Neuroscience May Change the Insanity Defence
Kaliski, Sean Z.
South African Journal of Psychiatry, Vol. 15, No. 1, March 2009
Peer-reviewed publications on Questia are publications containing articles which were subject to evaluation for accuracy and substance by professional peers of the article's author(s).
'You Can't See Why on a fMRI': What Science Can, and Can't, Tell Us about the Insanity Defense
Doherty, Brian.
Reason, Vol. 39, No. 3, July 2007
Those Crazy Insanity Pleas
Vatz, Richard E.
USA TODAY, Vol. 135, No. 2736, September 2006
By Reason of Insanity
Silverstein, Ken.
Mother Jones, Vol. 26, No. 5, September/October 2001
Dissociative Identity Disorder: No Excuse for Criminal Activity: Using Multiple Personalities as the Basis of an Insanity Defense Rarely Is Successful
Farrell, Helen M.
Current Psychiatry, Vol. 10, No. 6, June 2011
Gender Matters in the Insanity Defense
Breheney, Christian; Groscup, Jennifer; Galietta, Michele.
Law and Psychology Review, Vol. 31, Annual 2007
The Insanity Excuse and Retrograde Thinking
Vatz, Richard E.
USA TODAY, Vol. 139, No. 2790, March 2011
This Is Insane!
Paquette, Mary.
Perspectives in Psychiatric Care, Vol. 38, No. 3, July-September 2002
Peer-reviewed publications on Questia are publications containing articles which were subject to evaluation for accuracy and substance by professional peers of the article's author(s).
Should Courts Instruct Juries as to the Consequences to a Defendant of a "Not Guilty by Reason of Insanity" Verdict?
Ellias, Randi.
Journal of Criminal Law and Criminology, Vol. 85, No. 4, Spring 1995
Asphalt Justice: A Critique of the Criminal Justice System in America
John Raymond Cook.
Praeger, 2001
Librarian’s tip: Chap. 8 "Insanity and Mental Health"
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