automatism | Definition

Doc's CJ Glossary by Adam J. McKee
Course: Criminal Law

Automatism in criminal law is a defense that claims the defendant was not responsible for their actions due to a lack of conscious control or awareness caused by an external factor.


The defense of automatism in criminal law is a legal doctrine that allows a defendant to argue that they were not responsible for their actions at the time a crime was committed. Automatism refers to a state in which a person acts without conscious control or awareness, often due to an external factor such as a medical condition, sleepwalking, or the involuntary intake of drugs or alcohol.

The concept of automatism is rooted in the principle that criminal liability requires a culpable mental state, such as intent or knowledge. If a defendant was not aware of their actions or did not have the necessary mental state to commit the crime, it may be unfair to hold them legally responsible for the offense.

To raise the defense of automatism, the defendant must provide evidence that they were not in control of their actions at the time of the offense. This can be challenging, as the prosecution may argue that the defendant had the necessary mental state and was fully aware of their actions. The burden of proof is on the defendant to demonstrate that automatism was present, and this can require expert testimony from medical professionals or other experts.

One common example of automatism is sleepwalking. In cases where a defendant claims to have committed a crime while sleepwalking, the defense must demonstrate that the defendant was in a state of unconsciousness and lacked any awareness or control over their actions. This can involve a detailed analysis of the defendant’s medical history and sleep patterns, as well as witness testimony from anyone who observed the defendant during the episode.

Another example of automatism is the involuntary ingestion of drugs or alcohol. If a defendant can show that they were drugged or intoxicated without their knowledge or consent, they may be able to argue that they were not in control of their actions and lacked the necessary mental state to commit the crime. This defense is more likely to be successful if the defendant can demonstrate that they did not knowingly consume the substance, such as through the use of a spiked drink.

It is worth noting that the defense of automatism is not always successful, and courts are often skeptical of claims of unconscious behavior. The prosecution may argue that the defendant had some level of control or awareness or that they could have taken steps to prevent the episode from occurring. Furthermore, even if the defense of automatism is successful, the defendant may still be subject to civil liability or other consequences.


[ Glossary ]

Last Modified: 05/04/2023

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