Legal Definitions - insanity plea

The insanity plea is a defense used in criminal law that alleges a mental disorder caused the accused to commit the crime. It is also known as the insanity defense.

If successful, the defendant may not be acquitted but instead receive a special verdict of "not guilty by reason of insanity," which usually leads to their commitment to a mental institution.

There are different tests used to determine if the defendant was legally insane at the time of the crime, including the McNaghten Rules, Substantial-Capacity Test, Irresistible-Impulse Test, Durham Rule, and Appreciation Test.

One example of an insanity defense is the black-rage insanity defense, which is based on an African-American's violent eruption of anger induced at least partly by racial tensions. This defense was first used in the mid-1990s.

For instance, if an African-American person was charged with assault after being provoked by racial slurs and insults, they may use the black-rage insanity defense to argue that their mental state was affected by the racial tensions and they were not fully responsible for their actions.