Insanity - Legal Use of The Term

Legal Use of The Term

In United States criminal law, insanity may serve as an affirmative defense to criminal acts and thus does not need to negate an element of the prosecution's case such as general or specific intent. The States differ somewhat in their definition of insanity but most follow the guidelines of the Model Penal Code. All jurisdictions require a sanity evaluation to address the question first of whether or not the defendant has a mental illness.

Most courts accept a major mental illness such as psychosis but will not accept the diagnosis of a personality disorder for the purposes of an insanity defense. The second question is whether the mental illness interfered with the defendant's ability to distinguish right from wrong. That is, did the defendant know that the alleged behavior was against the law at the time the offense was committed.

Additionally, some jurisdictions add the question of whether or not the defendant was in control of their behavior at the time of the offense. For example, if the defendant was compelled by some aspect of their mental illness to commit the illegal act, the defendant could be evaluated as not in control of their behavior at the time of the offense.

The forensic mental health specialists submit their evaluations to the court. Since the question of sanity or insanity is a legal question and not a medical one, the judge and or jury will make the final decision regarding the defendant's status regarding an insanity defense.

In most jurisdictions within the United States, if the insanity plea is accepted, the defendant is committed to a psychiatric institution for at least 60 days for further evaluation, and then reevaluated at least yearly after that.

Insanity is generally no defense in a civil lawsuit. However, in civil cases, the insanity of the plaintiff can toll the statute of limitations for filing a suit until the plaintiff has recovered from this condition, or until a statute of repose has run.