The M’Naghten Rule 1843 – Criminal Law
Daniel M’Naghten (1813–1865), Edward Drummond (1792–1843), Nicholas Conyngham Tindal (1776–1846), Queen Victoria (1819–1901)
A test used to assess whether a person accused of committing a crime was sane at the time of the crime and hence criminally accountable.
The M’Naghten rule is used to determine if someone is insane enough to commit a crime. A criminal defendant is not guilty by reason of insanity under the M’Naghten rule if, at the time of the alleged criminal act, she was so deranged that she did not know the nature or quality of her actions, or if she did know the nature and quality of her actions, she was so deranged that she did not know what she was doing was wrong.