Temporary Insanity Law and Legal Definition

Temporary insanity is in a criminal prosecution, a defense by the accused that he/she was briefly insane at the time the crime was committed and therefore unable to have the wrongful intent required to be proved as an element of the crime. Temporary insanity is claimed as a defense regardless of the accused's sanity at the time of trial. Use of drugs or alcohol generally is not considered to be a factor.

The temporary insanity defense is difficult to prove, since any examination by psychiatrists had to be after the fact, so the only evidence must be the conduct of the accused immediately before or after the crime. Mental derangement at the time of a sudden crime, such as a crime of passion, can be a valid defense or at least show lack of premeditation to reduce the degree of the crime.

The defendant will be declared not guilty if found to be insane, but, if the condition still exists, the defendant may be incarcerated in a mental facility for the criminally insane or confinedin a mental hospital. If the insanity was temporary, the judge has the option to order psychological therapy, but the treatment varies from state to state.