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Automatism (WA)


The defence of automatism applies to criminal acts that are committed without conscious volition on the accused’s part. This includes acts that are committed while sleepwalking, during epileptic episodes, or while in a state of dissociation caused by physical trauma such as concussion. Western Australian legislation does not include automatism as a defence in its own right. However, the defences of unwilled acts under section 23A of the Criminal Code Act and insanity under section 27 are both closely related to automatism.

Unwilled acts (or ‘sane automatism’) 

Sane automatism is a state where a person loses control of themselves for a reason other than mental impairment. Examples of sane automatism include sleepwalking and concussion. In WA, these situations are captures by section 23A of the Criminal Code Act, which states:

A person is not criminally responsible for an act or omission that occurred independently of the exercise of the person’s will.

Insanity (or ‘insane automatism’)

Some forms of automatism are closely related to the defence of insanity, which is contained in section 27 of the Criminal Code. Under that provision, a person is not criminally responsible for an act done at a time when they were so mentally impaired that they could not understand what they were doing, could not control their actions or could not know that they should not do the action. Under this provision, if a person is in a delusional state, they are criminally responsible to the same extent as if the real state of affairs had been as the delusions made them believe.

Acquittal based on insanity

If a person is found not guilty of an offence because of insane automatism under section 27, they will not receive a full acquittal. Rather, they will be found not guilty due to mental impairment. They will then be dealt with under the Criminal Law (Mentally Impaired Accused) Act 1996.

Under the Criminal Law (Mentally Impaired Accused) Act 1996, a person who has been found not guilty due to mental impairment may be:

  • Released unconditionally (section 22);
  • Detained in an authorised hospital, detention centres, or prison (section 24);
  • Be released subject to a condition Release order (CRO) if the offence/s could have been dealt with by a CRO had the accused been found guilty;
  • Be released subject to a community-based order (CBO) if the offence/s would have warranted a CRO had the accused been found guilty;
  • Be released subject to an intensive supervision order (ISO) if the offence/s would have warranted a ISO had the accused been found guilty.

An accused person may be detained in a hospital only if they have a mental condition that is capable of being treated. 

Case law

The defence of automatism was considered in the below cases. 

R v Falconer

In the 1991 High Court decision of R v Falconer the accused was in a dissociative state following a series of psychological blows at the time of committing the acts making up the alleged offence. The accused had been subjected to ongoing verbal and sexual abuse by the victim. At the time of committing the offence the accused was found to have been in a state of dissociation and did not remember the acts she had committed. The court ordered a new trial on the basis that psychological evidence should be allowed to be adduced by the defence in pursuit of the defence of automatism.

Rabey v R

In Rabey v R the accused was a twenty-year-old university student who was found guilty of the offence of causing bodily harm with intent to wound. The accused had developed feelings for a classmate which were not returned and was hurt and angry. The accused attacked the complainant grabbing her arms, choking her and striking her on the head with a rock from the geology lab. In this case, it was found, The ordinary stresses and disappointments of life which are the common lot of mankind do not constitute an external cause.”

If you require legal advice or representation in any legal matter, please contact Go To Court Lawyers. 

Fernanda Dahlstrom

This article was written by Fernanda Dahlstrom

Fernanda Dahlstrom has a Bachelor of Laws, a Bachelor of Arts and a Graduate Diploma in Legal Practice. She has also completed a Master’s in Writing and Literature. Fernanda practised law for eight years, working in criminal defence, child protection and domestic violence law in the Northern Territory and in family law in Queensland.

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