A physical disease of the mind or damage to the brain will, if the circumstances permit, allow the defendant to raise the defense of insanity, and the M’Naghten rule can be extended to cover these type of situations.
In R v Kemp (1957) the defendant who was suffering from arteriosclerosis (a thickening or hardening of the arteries normally caused by old age) assaulted his wife with a hammer and the defendant was charged under section 18 of the Offences Against the Person Act 1861 for causing grievous bodily harm (GBH) to his wife. At the trial the defendant raised the defense of automatism but the trial judge directed the jury on insanity.
It was held that in order to determine if the defense (insanity) would avail itself to the defendant the court has to look into whether the mental faculties of reason, memory and understanding are impaired or absent and the physical state or condition of the mind is irrelevant. If the defendant was not able to comprehend or understand that the result of his actions would lead to dire consequences either to him or the victim than the defense would apply.
Likewise if the defendant is able to comprehend or understand the gravity of his actions, despite suffering from some sort of mental impairment, as in the case of R v Windle (1952) then the defense would not avail itself or would not be made available to the defendant.
Copyright © 2018 by Dyarne Ward