The appellant, an inmate in a maximum security institution, was threatened by a fellow inmate who was a member of a violent gang.
Anticipating an attack, the appellant concealed homemade weapons in his clothing.
When the fellow inmate attacked him with a knife, the appellant defended himself and killed the attacker.
The trial judge acquitted the appellant of murder based on self-defence, and of possession of a weapon for a purpose dangerous to the public peace, finding he possessed the weapons for deterrence and defence.
The Court of Appeal substituted a conviction on the weapons charge.
The Supreme Court of Canada allowed the appeal and restored the acquittal, holding that while a defensive purpose does not automatically mandate an acquittal, in these specific circumstances where the attack was imminent and unavoidable, the possession was not for a purpose dangerous to the public peace.