This month, David Walbank QC examines one of the longest established principles of criminal law: the courts’ approach to the concept of insanity
- Special verdict of not guilty by reason of insanity.
- Knowledge of wrongdoing but lack of capacity to control actions.
- No defence of ‘irresistible impulse’.
This month, we are concerned with a human tragedy, which prompted a review of one of the longest established principles of English criminal law. The Court of Appeal (Criminal Division) has recently revisited the so-called M’Naghten rules, which have governed the criminal courts’ approach to the concept of insanity in this jurisdiction since as far back as the mid-19th century. R v Keal [2022] EWCA Crim 341, [2022] All ER (D) 95 (Mar) turned on whether the defence of insanity was available to a psychotic and deluded defendant, who was aware that his acts were wrong but believed himself to be compelled to commit the offences in question.
The background to the case
Jonathan Keal, who was in his early
