The M'Naughten Rule

The M'Naughten Rule is a legal standard used to judge whether an offender is insane (and could thus base a defense on “not guilty by reason of insanity”). The rule states that individuals are not guilty of crimes if they lack awareness of their actions. Part of this awareness concerns knowledge of the wrongfulness of the act. An individual who is deemed not responsible for his or her actions cannot be held accountable for criminal conduct.

The origination of this rule can be traced back to 1843. Daniel McNaughten created controversy when he was tried and acquitted for the murder of the British Prime Minister's secretary, Edward Drummond. Upon investigation, it became apparent that Daniel had committed the murder due to a belief that the government ...