Is it true you can't be charged with a crime if you’re sleepwalking?

In the UK, it is possible to use sleepwalking as a defence against criminal charges, as sleepwalking falls under the legal concept of automatism. Automatism is a state where a person acts without conscious intention, meaning they were unaware of their actions at the time. This defence has been used most commonly in cases involving violent or sexual offences, where the defendant argues they were not in control of their actions due to sleepwalking.

Types of Automatism: Insane vs. Non-Insane

Automatism is categorised into two types: insane automatism and non-insane (or simple) automatism. The categorisation depends on the cause of the automatism:

• Non-Insane Automatism: This type is caused by external factors, such as sleepwalking, and if accepted by the court, it typically results in a simple acquittal or “not guilty” verdict.
• Insane Automatism: Caused by internal factors, this form of automatism leads to a special verdict of “not guilty by reason of insanity.” In these cases, sentencing is more complex, and options include an absolute discharge, a supervision order, or, in more severe cases, a hospital order.

Potential Outcomes in Court

If a sleepwalking defence is accepted under non-insane automatism, the defendant may receive a straightforward acquittal. In cases of insane automatism, however, the outcome may involve monitoring or specific conditions to ensure the defendant’s and the public’s safety.

Bottom Line

Sleepwalking can indeed be a valid defence against certain criminal charges in the UK, but its success depends on whether the court categorises it as non-insane or insane automatism. In cases where the defence is upheld, the defendant may either be fully acquitted or be subject to specific legal conditions.