In 1992, a Canadian man who stabbed his mother-in-law to death was found not guilty because he was sleepwalking.

The man fell asleep at home, in his living room. After a few hours, he got up and drove 23 kilometers to his in-laws’ house. Still asleep, he went inside, found a knife in the kitchen, and went to the bedroom where his in-laws were sleeping. He strangled and cut his father-in-law, who survived the attack. The mother-in-law died from repeated stab wounds and a brutal beating.

Medical experts agreed unanimously that the man was sleepwalking and thus was not performing voluntary acts.

The Canadian Supreme Court upheld the decision.