Common purpose

The doctrine of common purpose, common design, joint enterprise, or joint criminal enterprise is a common law legal doctrine that imputes criminal liability to the participants in a criminal enterprise for all that results from that enterprise. A common application of the rule is to impute criminal liability for wounding a person to participants in a riot who knew, or were reckless as to knowing, that one of their number had a knife and might use it, despite the fact that the other participants did not have knives themselves. In England and Wales and certain other Commonwealth countries, this was the understanding of the courts until February 2016, when the Supreme Court of the United Kingdom and the Judicial Committee of the Privy Council jointly ruled that it was wrong, and that nothing less than intent to assist the crime would do.

The common purpose doctrine was established in England and Wales, and later adopted in other common law jurisdictions including Scotland, Ireland, Australia, Trinidad and Tobago, Solomon Islands, Texas, Massachusetts, the International Criminal Court, and the International Criminal Tribunal for the former Yugoslavia.

An old example of this doctrine in English law is R v Swindall and Osborne (1846) 2 Car. & K. 230. Two cart drivers engaged in a race. One of them ran down and killed a pedestrian. It was not known which one had driven the fatal cart, but since they were encouraging each other in the race, it was irrelevant which of them had actually struck the man and both were held jointly liable. Thus the parties must share a common purpose and make it clear to each other by their actions that they are acting on their common intention, so that each member of the group assumes responsibility for the actions of the whole group. When this happens, all that flows from the execution of the plan makes them all liable. This is a question of causation, in that oblique intention will be imputed for intermediate consequences that are a necessary precondition to achieving the ultimate purpose, and liability will follow where there are accidental and unforeseen departures from the plan, so long as there is no novus actus interveniens to break the chain.

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