The actus reus consists of all elements of a crime other than the state of mind of the defendant. In particular it may consist of: conduct, result, a state of affairs or an omission.
Conduct - the conduct itself might be criminal. Eg. the conduct of lying under oath represents the crime of perjury. It does not matter that whether the lie is believed or if had any effect on the outcome of the case, the actus reus of the crime is complete upon the conduct.
Examples of conduct crimes:
Perjury
Theft
Making off without payment
Rape
Possession of drugs or firearm
Result - The conduct itself may not be criminal but the result of the conduct may be. Eg it is not a crime to throw a stone, but if it hits a person or smashes a window it could amount to a crime. Causation must be established in all result crimes.
Examples of result crimes:
Assault
Battery
ABH
Wounding and GBH
Murder & Manslaughter
Criminal damage
State of affairs - These are 'being' rather than 'doing' crimes. Eg being drunk in charge of a vehicle (Duck v Peacock [1949] 1 All ER 318 Case summary) or being an illegal alien (Larsonneur (1933) 24 Cr App R74 case summary).
Omission - The general rule regarding omissions is that there is no liability for a failure to act. Eg if you see a child drowning in shallow water and you don't do anything to save that child you will not incur criminal liability for your inaction no matter how easy it may have been for you to save the child's life. This general rule however, is subject to exceptions:
1. Statutory duty:
In some situations there is a statutory duty to act. Eg to provide details of insurance after a traffic accident or to notify DVLA when you sell a vehicle.
2. Contractual duty:
If a person owes a contractual duty to act then a failure to meet this contractual duty may result in criminal liability:
