“Automatism” – Involuntary Actions

Sometimes, an accused person will claim that they were not in control of their actions at the relevant time, for unforeseen external reasons. If someone does not know what they are doing, then it is hard to see how they could have the required mens rea to be criminally responsible. If someone’s state of consciousness is grossly impaired in some way, then that is the basis for the special defence of automatism (from the Greek word “automatos” = “acting by itself”).

Automatism isn’t to be confused with a claim of mental disorder. While both are concerned with the inability to form the required mens rea, mental disorder is defined as “mental illness, personality disorder, or learning disability”

Automatism is less innate; it is concerned with external factors that cause temporary loss of reason.

For example, an accused person may claim that an assault in a nightclub was the result of their drink being “spiked”. Alternatively, they may have recently suffered a blow that left them concussed, and not aware of what they were doing.

The leading case on automatism is Ross v HMA, which is available in full here.

Ross v HMA 1991 J.C. 210

  • Ross was charged with malicious damage, assault (including seven counts of attempted murder), breach of the peace and assaulting police officers.
  • There had been evidence that Ross had been drinking lager from a can. Unbeknownst to him, five or six tablets of temazepam and a quantity of LSD had been added to his drink, which he consumed. He then began acting wildly unpredictably.
  • Lord Justice-General Hope:the external factor which is alleged must not be self-induced, that it must be one which the accused was not bound to foresee and that it must be one which resulted in a total loss of control of his actions in regard to the crime with which he is charged.”
  • Lord Allanbridge:“In the present case, the appellant alleged that unknown to him his can of lager had temazepam and a quantity of L.S.D. squeezed into it with the result that he was deprived of his self-control to such an extent that he was incapable of mens rea. If this in fact was the effect of the drugs, and he was in such a mental condition that he was unable to form any intent—be it good or evil—then clearly he could not have the necessary mens rea to be guilty of a criminal offence.”
  • Ross’ convictions were quashed on appeal.

The three factors listed by Lord Justice-General Hope in Ross v HMA underpin the concept of automatism in Scots law. To elaborate slightly on each:

Not self-induced: “I was drunk” is not an excuse.

Not bound to foresee: For example, taking medication that causes drowsiness shortly before driving your car would, in all likelihood, make falling asleep at the wheel and causing a crash a foreseeable consequence.

Ebsworth v HMA 1992 SLT 1161

  • The accused had broken his leg, and was in a great deal of pain.
  • He addressed this by taking large quantities of legal and illegal painkillers (50 paracetamol tablets and 10 diamorphine tablets).
  • He became erratic, and committed various offences.
  • It was held that, although he may have taken the painkillers for a “legitimate” purpose, the quantities taken showed recklessness as to the side effects.
  • Therefore, the loss of reason suffered was foreseeable, and the special defence of automatism was not available to him.

Total loss of control: fact-sensitive. Would almost inevitably require expert medical evidence.

Sorley v HMA (1992 SCCR 396)

  • “[T]he whole point of the defence is that the accused was suffering from a total loss of control over his actions in regard to the crime with which he is charged. Unless there is evidence directed to this essential point, the defence is not available. It is a point of such importance that it cannot be left to speculation, and a few casual remarks or feelings by the witnesses will not do. There must be clear evidence to support it, and this means that the evidence must be specific on all details which are material. The evidence must relate to the state of mind of the accused. It must relate to the time at which the crime charged was committed. And it must provide a causative link between the external factor and the total loss of control. It is unlikely that these requirements will be satisfied unless there is some expert evidence, since the essence of the defence is a state of mind which requires to be precisely diagnosed and the cause of it must be explained.”

There is no definitive list of automatism scenarios, provided the criteria above are met. I have yet to encounter a case in which a client claims to have been hypnotised into committing a crime, but – theoretically – a malicious hypnotist could fit the bill.

Automatism is rarely relied upon as a defence (for example, there are various practical difficulties in proving that someone’s drink was spiked, if you don’t have access to the drink and have a toxicologist on standby), but it is worth being aware of. Here is a recent example of an unsuccessful automatism claim:


…and the subsequent appeal judgment (which doesn’t say much about the merits of the claim, relying instead on the reasoning in the Sheriff’s report to the Appeal Court):


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