At trial, appellant, Matthew Brown, was acquitted of breaking and entering with commission of aggravated assault. The accused attended a party where he consumed alcohol and magic mushrooms. While intoxicated, he broke into two homes, assaulting the occupant in the first residence and causing damage to property in the other. The accused challenged the constitutionality of s. 33.1 of the Criminal Code, which prohibited him from raising the defence of non-mental disorder automatism by reason of self-induced intoxication where his conduct interferes with the bodily integrity of another person. The trial judge held that s. 33.1 infringed both ss. 7 and 11(d) of the Canadian Charter of Rights and Freedoms and struck down that section. The trial judge then permitted Mr. Brown to raise the automatism defence and accepted the expert evidence that the accused was in a state of non-mental disorder automatism and acquitted him of all charges.

A unanimous Court of Appeal of Alberta allowed the Crown’s appeal and set aside the declaration of invalidity of s. 33.1. The Court set aside the acquittal and entered a conviction on the lesser and included offence of aggravated assault. No conviction was entered for break and enter as it was specific intent offence not covered by s. 33.1. Justice Slatter held that there was no risk of here convicting the morally innocent because those who voluntarily became intoxicated, where it was objectively foreseeable that while intoxicated, they might act in dangerous manner, were not morally innocent. Justice Hughes, concurring in result, reasoned that s. 33.1 does not provide a substitution for the mental element of the offence but rather another type of fault, which meets the principles of fundamental justice. Justice Khuller, also concurring in result, ruled that s. 33.1 breached the principles of fundamental justice but was constitutional as it was saved under s. 1 of the Charter.

Matthew Brown appealed to the Supreme Court of Canada as of right.