Court of Appeal · 3-0: Ward, Brooke and Walker LJJ (all concurring but with differing reasoning)
Facts
Jodie and Mary were conjoined twins. Jodie was the stronger twin, sustaining Mary's life through a shared circulatory system. Without separation, both would die within months. With separation, Jodie would survive but Mary would die. The parents refused consent on religious grounds. The NHS trust sought a declaration that the operation would be lawful.
History
The High Court (Johnson J) declared the operation lawful. The parents appealed. The Court of Appeal upheld the declaration.
Issue
Whether the surgeons would commit murder by performing an operation that would inevitably kill Mary. Whether the defence of necessity or the doctrine of double effect applies. Whether the operation is in the best interests of each child.
Held
Appeal dismissed (declaration upheld). The operation would be lawful.
Ratio
- Surgical separation of conjoined twins may lawfully be authorised where it is the only way to save the life of the twin who can survive, the other twin cannot survive in any event, and the operation is in the best interests of the child who can be saved; the doctors would have a defence of necessity to a charge of murder in these exceptional circumstances.
The judgments
Ward LJ (lead)
Held that the court had to weigh the interests of the two children, which carried equal weight, and that the balance favoured the operation because Jodie could survive and Mary would die soon in any event. He held that the doctors would have the defence of necessity to a charge of murder.
Brooke LJ (concurring)
Held that the operation would be lawful by reason of the defence of necessity, as the act was needed to avoid inevitable and irreparable evil, no more was done than was reasonably necessary, and the evil inflicted was not disproportionate to the evil avoided.
Walker LJ (concurring)
Agreed that the operation was lawful. He placed weight on the distinction between intending death and foreseeing it, treating the surgeons' purpose as saving Jodie and not killing Mary.
Key reasoning
- The court rejected the argument that the sanctity of life principle absolutely prohibits any intentional killing, even to save another life.
- The defence of necessity was accepted as applicable to murder in these exceptional circumstances, where the act saves a life that would otherwise be lost.
- The judges took different routes: Ward and Brooke LJJ rested lawfulness on the defence of necessity, while Walker LJ emphasised that the surgeons' purpose was to save Jodie rather than to kill Mary.
- Best interests analysis: the operation serves Jodie's best interests and does not violate Mary's because she has no independent prospect of life.
Obiter
- The court suggested that necessity might not be a general defence to murder but is available in this unique medical context.
- The judges emphasised that the decision was confined to the specific facts and did not establish a broad right to kill one person to save another.
Where it fits in the module
Re A illustrates the limits of the sanctity of life principle in homicide law and the role of defences (necessity, double effect) in exceptional medical cases. It contrasts with Dudley and Stephens (1884) where necessity was rejected as a defence to murder, and with Airedale NHS Trust v Bland (1993) on withdrawal of treatment. It is central to Topic 1 (principles of criminal liability, defences) and Topic 2 (homicide, intention, defences).
Criticisms
- The necessity defence in murder remains controversial and Re A may be confined to its extreme facts.
- The double effect analysis has been criticised as a fiction: the surgeons knowingly cause Mary's death as a means to save Jodie.
- The best interests reasoning for Mary is strained: it is difficult to say death is in her best interests.
- The decision avoids a clear ruling on whether necessity is a general defence to murder, leaving uncertainty.
Written with AI (nvidia/nemotron-3-ultra-550b-a55b) on 1 November 2026, reviewed for errors by a second model (claude-sonnet-5.5 (Claude Code reviewer)). Read the case itself at [2001] 2 W.L.R. 480, [2001] Crim. L.R. 400. Spotted an error? Tell us.