On 20 August 2019, it was reported that a 21-year-old man, Dale Kelly, had been acquitted of sexual assault against his friend’s girlfriend. Kelly, with a history of sleepwalking, successfully convinced the jury that he was not in control, nor was he aware, of his actions on account of his state of sleepwalking. As a result, Kelly was found “not guilty by reason of insanity”. This article seeks to consider the interrelation between the criminal law and sleepwalking.

In the early 1960s, Lord Denning pronounced that sleepwalking was an example of automatism; that being “an act which is done by the muscles without any control by the mind such as a spasm, a reflex action or a convulsion; or an act done by a person who is not conscious of what he is doing” (Bratty v AG of Northern Ireland [1963] AC 386). In 1991, however, the Court of Appeal in R v Burgess [1991] 2 QB 92 concluded that sleepwalking should be regarded as a defect of reason, caused by a disease of the mind (i.e. insanity) as opposed to being caused by an external factor (i.e. automatism).

Since Burgess, relatively few cases have come before the courts in which a defendant alleges sleepwalking as a defence. A number of reasons for this may exist; first, in order to rely on sleepwalking as a defence, medical evidence would be required to support such a claim and this would be contested by the prosecution; second, should the sleepwalking be brought about by way of self-induced intoxication, the defence is not capable of being run; and finally, the outcome of a successful defence is not the most appealing one for an accused person.

In particular, following an acquittal by reason of insanity, a defendant is not entitled to “walk free”, per se. Rather, the trial judge must consider whether to detain the individual by way of a Hospital Order, issue a Supervision Order or release him. The risk of a Hospital Order being issued by the trial judge is sufficient for most defendants, Burgess included in the 1990s, to change their plea to “guilty”.

The term “insanity” is perhaps a rather harsh categorisation for an individual who sleepwalks. Indeed, the authors of Smith, Hogan and Ormerod’s Criminal Law suggest that to use the term “insanity” is ‘profoundly misleading’. A normal person who happens to commit an offence while sleepwalking is now considered to be legally “insane” despite the little basis in medicine or law to justify the use of such a term. Following on from this, it is interesting to note that a number of Crown Court cases have been reported as involving acquittals on the basis of automatism (the outcome of which is an absolute discharge, i.e. the individual walks free), as opposed to insanity.

These included R v Bilton (2005) The Guardian (20 December), which concerned a charge of rape, and R v Davies (2006) The Times (11 February) which concerned a sexual assault. In addition, cases have been discontinued by the Crown Prosecution Service on the basis that it would not be in the public interest to hospitalise an individual who commits an offence while sleepwalking. The case of Dale Kelly demonstrates the apparent lack of consistency in approach adopted by the courts or the CPS.

Whilst the defence remains uncommon in practice, it retains its controversy. In October 2008, Harry Cohen MP introduced a Private Member’s Bill entitled the Rape (Defences) Bill. The Bill was introduced to amend the Sexual Offences Act 2003 to prohibit the defence of sleepwalking or other automatism from being claimed in cases of rape following the media coverage of a number of cases where defendants successfully raised a defence of sleepwalking to charges involving sexual offences. The Bill was never enacted having only ever received its first reading. It will be interesting to see whether the case of Dale Kelly reignites this Bill or leads to the introduction of a similar Bill in the near future.

By way of final words, the defence of sleepwalking remains relatively uncommon in the criminal justice system; the defence itself is inconsistently applied due to the distinction between insanity and non-insane automatism; and the defence remains a controversial one for the complainants of any criminal conduct committed whilst an individual sleepwalks. At this moment, the common law accepts the defence as a possibility; only legislative action would likely cause a change in this fact.

Mark Thomas is a senior lecturer in law at Nottingham Law School, Nottingham Trent University.