ABSTRACT
Automatism is a rarely used defence, although it is difficult to ascertain accurately how often it is argued. The defence of automatism is in fact at least three separate defences–denial of the actus reus, denial of the mens rea, and the insanity defence. These three defences have a combination of different standards for culpability along with different standards and burdens of proof. This makes the law confusing even for the judiciary and legal profession. The judiciary continues to evince reluctance to instructing the jury to consider the insanity defence. The Law Commission voiced concerns over the use of medical conditions to argue lack of mens rea in their discussion document. Education on the basis of the legal doctrines would be likely to improve the quality of expert evidence. Ultimately, much of the case law has roots in policy issues, and this explains why the automatism defence as it stands lacks a convincing justification in jurisprudence or medical science.
