Swedish law recognises two types of participation in crime, acting as a principal and furthering of a crime through complicity. Under exceptional circumstances a party to a crime can be discharged from criminal liability altogether, namely if his contribution to the crime was induced by strong influence, or was of minor importance, and the circumstances in the case were such that the crime is judged to be a petty offence. Another typical case where the roles of the perpetrators are likely to be re-labelled is a situation where the complicity object has been established through acquisition of an excess mens rea element from the furtherer. The notion of an 'innocent agent' derives its significance from the concept of indirect perpetration. The responsibility for complicity presupposes something in which the accomplice can participate. In Swedish legal doctrine this is normally referred to as a complicity object.