Dunlop v R

Dunlop v R, [1979] 2 S.C.R. 881 is the leading decision of the Supreme Court of Canada on participating in a criminal act by aiding and abetting. The Court held that the mere presence of the accused at the scene of a criminal act is not sufficient to convict the person for aiding and abetting a criminal act. There must be something more.
Background.
Two teenagers, Dunlop and Sylvester, were members of a motorcycle club. One evening they went to a party held by the club where other members were involved in a gang rape of a teenage girl.
The girl testified at trial that the two teens had participated in the rape. The trial judge directed the jury to find whether the teens had participated enough to have aided or abetted the rape under section 21(1) of the "Criminal Code" or had a common intention to rape the victim under section 21(2) of the "Criminal Code".
Opinion of the Court.
Justice Dickson wrote the decision for the majority. He held that the trial judge had erred in instructing the jury to consider the "common intention" provision of the Criminal Code. The sole issue was whether the teens had aided and abetted the commission of the crime. In considering the provision he held that:
Accordingly, the two teens were acquitted.