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What is Automatism?

Where a person who has been charged with a criminal offence suggests that they committed the physical acts involuntarily, they are raising the defence of automatism. The defence of automatism is based on a very basic principle of criminal law: that a person cannot be found guilty of an act which occurred without the exercise of their will. This is not so much a ‘defence’ as a claim by the defence that the prosecution cannot prove one of the elements of the offence charged; that the accused acted voluntarily. If the offence does not require the accused to have acted voluntarily, then automatism generally cannot be argued.

What is automatism?

Automatism is a legal term used to describe a situation where acts occurred without the volition of the accused. The determining factor is whether the accused exercised their will rather than a lack of consciousness or knowledge on the part of the accused.

For example, where a person is conscious of what is happening but is unable to control their actions, and is essentially disassociated from them, they may be acting involuntarily and as an ‘automaton’. Automatism may be established if there was no deliberation in the behaviour, and the accused acted automatically. However, it is not about not understanding that one’s actions were ‘wrong’. Not being aware that something was wrong, and going ahead and doing it deliberately, is not ‘automatism’.

What are the types of automatism?

There are two types of automatism.

Insane automatism

The first type of automatism is ‘insane automatism’. This exists when the cause is a ‘disease of the mind’. This phrase has been determined by courts to be the same as ‘mental impairment’. However, this is not just any mental impairment, like being impaired by anger or some other overwhelming emotion. It means that the person’s ability to understand and be cognisant of the situation is in disarray, and this is the result of the unsound mind’s reactions to its own delusions or to external events and situations. A person in a state of insane automatism cannot be found guilty of an offence.

Sane automatism

The second type of automatism is ‘sane automatism’. This is very rare as few occurrences or conditions amount to automatism but fall outside of the category of ‘diseases of the mind’. An example is an act done while a person is sleepwalking.

Burden of proof

Which party bears the burden of proof when automatism is raised depends on whether the defence is arguing sane or insane automatism.

Where the defence raises sane automatism the onus of proof rests on the prosecution, which must establish that the accused acted voluntarily beyond a reasonable doubt. Should it fail to do this, the accused must be acquitted.

Insane automatism only requires that the defence show that on the balance of probabilities the defence of mental impairment is made out. If this can be shown, then the verdict must be not guilty by reason of mental impairment.

There are instances where both types of automatism may arise and determining a verdict in such a case can be complex. An acquittal is not the same as a finding of not guilty by reason of mental impairment.

What is a ‘disease of the mind’?

Various cases have raised the question of what conditions amount to a ‘disease of the mind’. These include schizophrenia, brain injuries and physical conditions of the brain. Hyperglycaemia has been found to be a disease of the mind, as have some physical diseases such as brain tumours.

There are some conditions which may or may not be found to amount to a disease of the mind, depending on the circumstances of the individual case. In some circumstances, it has been found to be possible to act voluntarily while in a dissociative state.

Amnesia is not proof of automatism. A person having amnesia does not mean they acted automatically, and the absence of amnesia is not necessarily an indication that the person did not act automatically. Whether automatism is found to have existed depends on what the accused’s state of mind was at the time, regardless of whether they have a recollection of their behaviour afterwards.

What about ‘intoxication’?

In some circumstances, acting involuntarily due to a high consumption of alcohol or drugs may amount to automatism. However, an accused’s intoxication also raises other issues that are considered separately by the courts from this issue. 

If you require legal advice or representation in any legal matter, please contact Armstrong Legal.

Michelle Makela

This article was written by Michelle Makela

Michelle has over 15 years experience in the legal industry, working across commercial litigation, criminal law, family law and estate planning.  Michelle has been involved in all practice areas of the firm and in her personal practice has had experience in litigation at all levels (State and Federal Industrial Tribunals, the Supreme Court, Court of Appeal, the Federal Court, Federal...

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