The Actus Reus of murder is the unlawful killing of a reasonable creature in being and under the Queen’s Peace. The killing must be unlawful. It is not unlawful if what is done is in self-defence, or in the prevention of crime and the defendant used reasonable force under the circumstances. The Actus Reus can be an act or omission but it must cause the death of the victim. Murder is a result crime; the defendant cannot be guilty unless his act or omission caused the death. Omissions as Actus Reus In nearly every case the actus reus will be an act such as stabbing the victim, shooting them or running them over. The normal rule is that an omission cannot make a person guilty of an offence. This was explained by Stephen J, a nineteenth century judge “A sees B drowning and is able to save him by holding out his hand. A abstains from doing so in order that B may be drowned. A has committed no offense.” Exceptions to the Rule There are exceptions to the rule that an omission cannot make a person guilty of an offence. In some cases it is possible for a failure to act to be the actus reus. An omission is only sufficient for the actus reus where there is a duty to act. There are four main situations in which such a duty can exist. 1. A contractual duty. 2. A duty because of a relationship 3. A duty which has been taken on voluntarily. 4. A duty which arises because the defendant has set in motion of a chain of events Contractual Duty In Pittwood 1902 a railway crossing keeper failed to shut the gates of the crossing when a train was due. As a result a person crossing the line was struck by a train. The keeper was guilty of manslaughter. A more modern example would be of a lifeguard at a pool who leaves his post unattended. His failure to do his duty under his contract of employment could make him guilty of an offence if a swimmer were injured of drowned. A Duty Because of a Relationship This is usually a parent-child relationship sin