Insanity Plea
An important distinction: "Not guilty by reason of insanity" and "diminished capacity"
Although a defense known as "diminished capacity" bears some resemblance to the "reason of insanity" defense (in that both examine the mental competence of the defendant), there are important differences. The most fundamental of these is that, while "reason of insanity" is a full defense to a crime -- that is, pleading "reason of insanity" is the equivalent of pleading "not guilty" -- "diminished capacity" is merely pleading to a lesser crime.
One of the most famous recent uses of the insanity defense came in United States v. Hinckley, concerning the assassination attempt against then-President Ronald Reagan.
The history of "not guilty by reason of insanity"
The insanity defense reflects a compromise on the part of society and the law. On the one hand, society believes that criminals should be punished for their crimes; on the other hand, society believs that people who are ill should receive treatment for their illness. The insanity defense is the compromise: basically, it reflects society's belief that the law should not punish defendants who are mentally incapable of controlling their conduct.
In the 18th century, the legal standards for the insanity defense were varied. Some courts looked to whether the defendant could distinguish between good and evil, while others asked whether the defendant "did not know what he did." By the 19th century, it was generally accepted that insanity was a question of fact, which was left to the jury to decide.
The McNaughton rule -- not knowing right from wrong
The first famous legal test for insanity came in 1843, in the McNaughton case. Englishman Daniel McNaughton shot and killed the secretary of the British Prime Minister, believing that the Prime Minister was conspiring against him. The court acquitted McNaughton "by reason of insanity," and he was placed in a mental institution for the rest of his life. However, the case caused
Although a defense known as "diminished capacity" bears some resemblance to the "reason of insanity" defense (in that both examine the mental competence of the defendant), there are important differences. The most fundamental of these is that, while "reason of insanity" is a full defense to a crime -- that is, pleading "reason of insanity" is the equivalent of pleading "not guilty" -- "diminished capacity" is merely pleading to a lesser crime.
One of the most famous recent uses of the insanity defense came in United States v. Hinckley, concerning the assassination attempt against then-President Ronald Reagan.
The history of "not guilty by reason of insanity"
The insanity defense reflects a compromise on the part of society and the law. On the one hand, society believes that criminals should be punished for their crimes; on the other hand, society believs that people who are ill should receive treatment for their illness. The insanity defense is the compromise: basically, it reflects society's belief that the law should not punish defendants who are mentally incapable of controlling their conduct.
In the 18th century, the legal standards for the insanity defense were varied. Some courts looked to whether the defendant could distinguish between good and evil, while others asked whether the defendant "did not know what he did." By the 19th century, it was generally accepted that insanity was a question of fact, which was left to the jury to decide.
The McNaughton rule -- not knowing right from wrong
The first famous legal test for insanity came in 1843, in the McNaughton case. Englishman Daniel McNaughton shot and killed the secretary of the British Prime Minister, believing that the Prime Minister was conspiring against him. The court acquitted McNaughton "by reason of insanity," and he was placed in a mental institution for the rest of his life. However, the case caused