Actus reus

Actus reus, Latin for 'guilty act,' is the external or physical element of a criminal offence. It usually consists of prohibited conduct (an act or, where a legal duty exists, an omission), often together with specified circumstances or consequences, such as causing bodily harm. The conduct must generally be voluntary in the sense of being a willed act.

The actus reus and mens rea together define an offence, and in Canadian law the Crown must prove each element beyond a reasonable doubt, with the fault element coinciding with the prohibited act. When analysing an offence, lawyers break the charging provision into its actus reus components and its mens rea components, then match the evidence against each; a failure of proof on any essential element means an acquittal.