Principles of Criminal Liability — SQE1 practice question

A man is replacing a light fitting in a shop when he touches a live wire and receives a severe electric shock. His arm jerks violently backwards and the screwdriver in his hand cuts the face of a woman who is holding the foot of his ladder. The cut needs stitches. Medical evidence is that the shock caused an uncontrollable muscular spasm and that he had no control over the movement of his arm. He is charged with assault occasioning actual bodily harm.

Is the man criminally liable for the injury caused by the movement of his arm?

Option A. Incorrect answer. Yes, because he chose to work on a live fitting with a woman standing directly beneath him.
Option B. Correct answer. No, because the movement of his arm was not willed, and liability requires a voluntary act.Correct
Option C. Incorrect answer. No, because the shock left him with no memory of the incident, so he lacked the mental element.
Option D. Incorrect answer. Yes, because the injury flowed directly from his own act of taking hold of the screwdriver.
Option E. Incorrect answer. No, because a person who acts under an uncontrollable impulse is entitled to be acquitted of any charge.

Why

The correct answer is B. The actus reus of an offence must be a voluntary act: the defendant must have consciously willed the movement that produced the prohibited result. A muscular spasm caused by an electric shock is not a willed movement, so on this medical evidence there is no act capable of founding liability and the charge must fail. The same reasoning applies to reflexes, convulsions and acts done while unconscious, and it reflects the principle that the criminal law punishes blameworthy choices.

A is incorrect because he is charged with the harm done by the spasm, not with an earlier decision to work on a live fitting; any careless act of that kind would have to be charged and proved on its own terms.

C is incorrect because amnesia is not the point: losing one's memory of an event neither proves nor disproves loss of control at the time, and here it is the absence of control that matters.

D is incorrect because the relevant act is the involuntary movement of the arm, not the earlier voluntary act of picking up the screwdriver.

E is incorrect because irresistible impulse is no defence in English law; a defendant who acts on an urge he finds hard to resist is still willing the movement.

Why

C is incorrect because amnesia is not the point: losing one's memory of an event neither proves nor disproves loss of control at the time, and here it is the absence of control that matters.

D is incorrect because the relevant act is the involuntary movement of the arm, not the earlier voluntary act of picking up the screwdriver.

E is incorrect because irresistible impulse is no defence in English law; a defendant who acts on an urge he finds hard to resist is still willing the movement.