2. Actus reus

The actus reus can be more than one act. It is the external element: the act, the circumstances, and, in a result crime, the consequence. Every crime has its own. Rape, as stated here, is carnal knowledge of a woman without her consent. The lack of consent is a circumstance that exists independently of the act. Larceny is taking and carrying away, without the owner's consent, something capable of being stolen, with the intention of permanently depriving the owner. If the thing already belongs to the taker, there is no larceny, whatever the intention.

The same stabbing is the actus reus of murder if the victim dies, and of causing grievous bodily harm if the victim survives. The consequence decides which actus reus it is. R v White is the illustration of a result that was wanted and did not happen. White put cyanide in his mother's drink. She was found dead, with the glass beside her. She had died of heart failure, not of the poison. He was not guilty of murder. He was guilty of attempt. There is always an actus reus. Even a strict-liability offence still requires the external element.

Why the law insists on an act. A specific act gives some protection against a false charge. It also shows that the intention has been expressed in a way that harms society. A bare agreement to commit a crime is already conspiracy. Words of encouragement can be enough for aiding and abetting.

Conduct crimes and result crimes. A conduct crime is complete when the forbidden conduct happens. Possession of drugs or of a firearm is the example. No further harm has to be proved. A result crime requires a prohibited consequence. Murder requires the death of another person. Both kinds require an act, and both require the legally relevant circumstances. A result crime adds causation.

The act must be voluntary. It is a willed muscular movement. John Austin called an act a voluntary movement of the body, or a movement that follows volition. Holmes called it a willed muscular contraction. Unconscious conduct is not willed. Glanville Williams added that an act is more than a bodily movement, because a person can trip and fall.

Lord Denning in Bratty v Attorney-General for Northern Ireland said no act is punishable if it is involuntary. Automatism is an act done by the muscles without any control by the mind: a spasm, a reflex, concussion, or an act done while unconscious of it, such as sleepwalking. It is not automatism merely because the person does not remember, or because of an irresistible impulse. Involuntary conduct is a complete defence.

What excludes voluntariness is physical compulsion, a reflex, concussion, unconsciousness, and, on the dicta, hypnosis. Unconsciousness from an external cause, such as a therapeutic anaesthetic, is non-insane automatism. Unconsciousness from an internal condition may be treated as insanity, as a matter of policy. In R v Sullivan an assault during recovery from an epileptic fit was disease of the mind within the M'Naghten Rules. The verdict was not guilty by reason of insanity. In R v Quick a diabetic's hypoglycaemia was the other way. The Court of Appeal held that the blackout was not a disease of the mind, and that automatism should have been left to the jury. Hill v Baxter is the driving case. A purely reflexive movement, such as from a swarm of bees, is not driving.

A crime can be committed by omission, but only where the law recognises a duty to act. There are four situations. A duty under a contract: Pittwood, the crossing-keeper who went to lunch and left the gate open. A duty from a relationship, parents and children, or spouses. The Children and Young Persons Act 1933 makes wilful parental neglect an offence. A duty from assuming care of someone helpless: Instan, and Stone and Dobinson. A duty from creating a dangerous situation: Miller, the squatter who woke to a smouldering mattress, moved to another room, and let the house burn. Once he knew of the risk he had started, failure to take steps within his power was the actus reus of criminal damage.

Status offences punish a state of affairs. Larsonneur was brought to England in custody and was still convicted of being found here after leave to land had been refused. Winzar was put on the highway by the police and convicted of being found drunk there. Martin v State, in Alabama, went the other way: a voluntary appearance is presupposed, and a man carried onto the highway by the police has not appeared there. Powell v Texas held that a chronic alcoholic can still be punished for being found drunk in public, which is conduct, not the status of alcoholism alone. Lim Chin Aik shows the limit on a prohibition that was never brought to the person's notice. Subordinate legislation binds only when it has been promulgated.