M’Naghten Case

Dating back to 1843 Britain, the case of Daniel M’Naghten put mental illness on the criminal system’s radar. A Scottish woodturner, M’Naghten shot the prime minister’s private secretary point blank, saying that the British Tories’ persecution “entirely destroyed [his] peace of mind” and compelled him to pull the trigger. He was found not guilty on grounds of insanity.

The case set a precedent that was adopted in the Canadian Criminal Code for 100 years. It defined mentally ill people as those plagued with a “natural imbecility” or “disease of the mind.” The mentally unfit were thought to be incapable of understanding the gravity of their crimes.

R. v. Swain

Fast forward 140 years, Canadian Owen Swain was arrested in 1983 for a bizarre attack against his wife and children. Swain believed he was protecting his family from being assaulted by demons, matching his wife’s testimony about him “fighting the air” and speaking about spirits during the incident. After an appeal, Swain, who was in jail, was discharged.

For decades, doubts were cast on the effectiveness of the definition of insanity, but Swain’s case changed that: Bill C-30 was created to more aptly reflect the attitudes of the time.

The defence itself was changed to “mental disorder” to cover a wider range of psychiatric problems. The terms “natural imbecility” and “disease of the mind” were also struck from the definition. These changes showed society’s deliberate attempt to reduce the stigma of insanity in favour of a more neutral and sympathetic view.

R. v. Chaulk

In the fall of 1985, 15-year-old Robert Chaulk and 16-year-old Francis Morrissette broke into George Haywood’s Winnipeg home and beat him to death. The teenagers reportedly suffered from paranoid psychosis, making them believe they could rule the world but would have to kill others in order to take full control. Both were convicted of murder but appealed the decision on the grounds of Section 16 in the Criminal Code.

The Supreme Court held that “wrong” meant “morally wrong” and not “legally wrong.” By establishing this, it reaffirmed that to be deemed insane, the accused must be unable to tell right from wrong.

McLean v. Li

One of the most recent insanity cases in Canada is the Greyhound bus murder of Winnipeg resident Tim McLean. The killer, Vince Weiguang Li, beheaded and cannibalized his fellow passenger but was found not criminally responsible for the murder.
Outrage over the decision poured out especially from McLean’s family. McLean’s mother, Carol deDelley, has proposed amendments to the definition of insanity and the “not criminally responsible” designation. DeDelley continues to lobby for changing “not criminally responsible” to “not psychologically accountable,” which means that the person is still criminally responsible. The movement gained traction in its early periods but more recently has remained under the radar.