Automatism (law)

Automatism is a rarely used criminal defence. It is one of the mental condition defences that relate to the mental state of the defendant. Automatism can be seen variously as lack of voluntariness, lack of culpability (unconsciousness) or excuse (Schopp). Automatism means that the defendant was not aware of his or her actions when making the particular movements that constituted the illegal act. For example, Esther Griggs in 1858 threw her child out of a first floor window believing that the house was on fire, while having a night terror. Brian Thomas strangled his wife in their campervan in a more recent case in Aberporth in an episode of rapid eye movement sleep behaviour disorder (a disorder related to sleepwalking), where he dreamed there was an intruder on top of his wife. The defence of automatism is denying that the person was acting in the sense that the criminal law demands. As such it is really a denial-of-proof – the defendant is asserting that the offence is not made out. The prosecution does not have to disprove the defence as is sometimes erroneously reported; the prosecution has to prove all the elements of the offence including the voluntary act requirement. Automatism is a defence even against strict liability crimes like dangerous driving, where no intent is necessary.

There are several limitations to the defence of automatism in English law. Prior fault generally excludes automatism. Intoxication generally excludes automatism, even when involuntary. Any defence that rests on insanity comes under the M'Naghten Rules. Under English law internal causes of automatism are generally judged to be insane automatism and so result in the special verdict ('not guilty by reason of insanity') rather than simple acquittal.

Automatism is arguably the only defence that excludes responsibility by negating the existence of the actus reus which uniquely allows it to be a defence to both conventional and strict liability offences (although this argument could be extended to the status defence of insanity too). Strict automatism is a denial of actus reus and therefore most commonly used as a defence against strict liability offences. There are a number of reasons why a person may go into a state of automatism, including dissociation or hypo/hyperglycemia. Unconsciousness is the defence of denial of mens rea, which is easier to prove and hence more commonly used for non-strict liability crimes. For example, in cases of homicidal sleepwalking the illegal act is typically not denied but the intent to kill is. The defendant will typically be perplexed and confused and will not cover up the episode. Kenneth Parks, after killing his mother-in-law and severely injuring his father-in-law, drove to the police station stating that he thought he'd killed some people. The person's movements seem purposeful - the sleepwalker interacts with his environment in a limited way. Nonetheless the sleepwalker is not conscious of his actions. The use of the term automatism for these situations causes some confusion, as in these cases it is really the lack of intent on the part of the defendant which denies the mens rea of the offence rather than the actus reus (although this distinction is problematic in many instances), better called unconsciousness. Intention is a problem in crimes of strict liability. Very few people intend to crash their vehicles, so clearly something better than intent is required to define automatism.

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