In English law, a person can only be criminally liable if they have committed the actus reus element of a crime with the necessary mens rea. However, it is not enough to simply prove that the defendant undertook the acts prohibited by the actus reus of the offence as in order to invoke liability, the law requires that the criminal act be voluntary.
When is an Act Involuntary?
In the case of Bratty v. Attorney-General for Northern Ireland [1963], Lord Denning defined an involuntary action as an act done “by the muscles without any control by the mind .. or … by a person who is not conscious of what he is doing”.
This presents two forms of involuntary action: nervous or involuntary responses, such as spasms or convulsions, and unconscious actions, such as sleepwalking. Such involuntary actions are the result of what the law refers to as non-insane automatism.
The infamous case of Hill v. Baxter [1958] provides an example of involuntary response: a driver attacked by a swarm of bees and who is therefore found driving erratically was not convicted of dangerous driving as the court determined that “he is no longer driving.” The attack caused the driver to lose control of the vehicle due to the involuntary, and no doubt panicked, response of trying to rid himself of the bees.
Unconscious actions such as sleepwalking have been newsworthy on several occasions. In the so-called sleepwalker killer cases of Jules Lowe and Brian Thomas, the defendants faced trial for murder after killing another person while asleep. In both cases, the defendant was found not guilty of murder.
Insanity as a Defence
While Thomas was found not guilty by the court, Lowe received a verdict of not guilty for reasons of insanity; and subsequently spent several months in a psychiatric hospital before he was discharged on the grounds that he was not a threat to the public. This is because sleepwalking may be seen by the law as a “disease of the mind” and thus allows a defendant to plead insanity as a defence.
For an insanity plea to be accepted, a defendant must be suffering from a disease of the mind causing a defect of reason that prevents him knowing either “the nature and quality” of his actions, or that what he did was wrong. If accepted by a jury, such a plea grants the court the power to either grant an absolute discharge, allowing the defendant to walk free, or section him under the Criminal Procedure (Insanity and Unfitness to Plead) Act 1991.
What is a Disease of the Mind?
What the law recognises as a disease of the mind was developed in R v. Kemp [1957] and refined in R v. Sullivan [1984]. In short, diseases of the mind are physical or mental diseases that affect mental functioning but do not result from external factors such as drinking one's self into a stupor or being hit over the head. This definition has caused controversy over the years, as it leads to the potential for diabetics, amongst others, being classed as insane by the courts; as in the case of R v. Hennessy [1989].
Excepting the potential crossover in the case of sleepwalking, non-insane automatism is usually differentiated from insanity as a defence against criminal liability. It provides a means for the courts, in the name of justice, to acquit a defendant who involuntarily commits an otherwise criminal act. Although its grounds for use are severely limited, its existence as a defence provides a modicum of finesse to the usually blunt instrument of the law.
Zoe Kirk-Robinson - Zoë Kirk-Robinson is a freelance writer/artist specialising in legal writing, internet technology and creative writing. She holds a ...
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