Legal Case Summary
R v Smith [1959] 2 QB 35
Facts
The defendant was a soldier who stabbed one of his comrades during a fight in an army barracks. The victim was taken to receive medical attention, but whilst being carried to the hospital was dropped twice by those carrying him. Once at the hospital, he received negligent medical treatment; the medics failed to diagnose a puncture to his lung. The victim died of his injuries, and the defendant was charged with murder and convicted at first instance. The defendant appealed on the basis that the victim would have survived but for the negligence of those treating him. He also argued that his confession had been obtained under duress and was therefore inadmissible.
Issues
The issue was whether the negligence on the part of the doctors was capable of breaking the chain of causation between the defendant’s action in stabbing the victim, and his ultimate death.
Decision/Outcome
The court held that the stab wound was an operating cause of the victim’s death; it did not matter that it was not the sole cause. In order to break the chain of causation, an event must be:
“…unwarrantable, a new cause which disturbs the sequence of events [and] can be described as either unreasonable or extraneous or extrinsic” (p. 43).
The chain of causation was not broken on the facts of this case.
With respect to the issue of duress, the court held that as the threat was made some time before the relevant confession and was no longer active at the time of the defendant’s statement, it did not render the evidence inadmissible. The conviction for murder was therefore upheld.
Updated 20 March 2026
This case summary accurately reflects the decision in R v Smith [1959] 2 QB 35, which remains good law on the principles of causation in criminal law. The ‘operating and substantial cause’ test established in Smith continues to be applied by the courts and is consistently cited alongside later authorities such as R v Cheshire [1991] 1 WLR 844, which refined the approach to medical negligence as a potential novus actus interveniens. Readers should note that Cheshire is now generally regarded as the leading case on the specific question of whether negligent medical treatment breaks the chain of causation, setting a higher threshold than Smith might suggest: only where medical treatment is so independent and potent a cause that it renders the original wound merely part of the history will causation be broken. The core principles described in this summary therefore remain accurate, but students should read Smith alongside Cheshire and R v Malcherek [1981] 1 WLR 690 for a full picture of the current law in this area.
