Insanity Defense Definition and Legal Meaning

On this page, you'll find the legal definition and meaning of Insanity Defense, written in plain English, along with examples of how it is used.

What is Insanity Defense?

In criminal cases the defense made during the trial that the accuse was not aware that he/she was commiting a crime as he/she was of unsound mind and because of this defect he was not able to judge that the act was illegal.The act was perfromed because of a mental defect and was not commited intentionally.

History and Meaning of Insanity Defense

The insanity defense, also known as the mental disorder defense, is a legal defense used in criminal trials that asserts that the defendant was not responsible for their actions due to a mental illness or defect. The underlying principle of this defense is that a defendant should not be held criminally liable if they were incapable of distinguishing right from wrong at the time of the offense due to their mental condition.

The concept of the insanity defense dates back to ancient Greece and Rome, but it wasn't until the British courts established the M'Naghten Rule in 1843 that the modern concept of an insanity defense was established. Today, the use of the insanity defense varies from country to country, with some nations rejecting it altogether, while others have different standards for its application.

Examples of Insanity Defense

  1. In 2018, a man who shot and killed four people at a Tennessee Waffle House was found unfit to stand trial due to his mental illness.
  2. John Hinckley Jr., who attempted to assassinate President Reagan in 1981, was found not guilty by reason of insanity and was confined to a mental institution until his release in 2016.
  3. In 2013, a Colorado jury rejected the insanity defense plea made by James Holmes, who had shot and killed 12 people inside a movie theater.

Legal Terms Similar to Insanity Defense

  1. Competency to Stand Trial - Refers to whether a defendant is mentally competent to participate in their own criminal trial.
  2. Diminished Capacity - Refers to a partial loss of cognitive or emotional functioning and the inability to form intent or premeditation necessary to commit a crime.
  3. Guilty but Mentally Ill - Refers to defendants who are found guilty of a crime but are also determined to have a mental illness that contributed to their criminal behavior.