ABSTRACT
Perhaps the most serious medical complaint which could be made against a doctor is that they have killed a patient, either deliberately or negligently. Fortunately such cases remain rare, but when they do happen, media coverage is extensive. Very few doctors have been prosecuted for killing patients in the UK, and very few of these prosecutions have been successful. Perhaps the main reason for this is that a defence can exist against charges of murder: the doctrine of double effect (DDE). The doctrine was first described in the thirteenth century by St Thomas Aquinas, in his discussions about whether it was lawful to kill in self-defence.1 The doctrine now forms part of international case law as providing a defence against a charge of murder in certain circumstances. There are four stated criteria within the DDE, all of which must be satisfied if a defence is to be proven:
1 The act must be good, or at least morally neutral (independent of its consequences).
