The doctrine of common purpose, common design, joint enterprise, joint criminal enterprise or parasitic accessory liability is a common law legal doctrine that imputes criminal liability to the participants in a criminal enterprise for all reasonable results from that enterprise. The common purpose doctrine was established in English law, and later adopted in other common-law jurisdictions including Scotland, Ireland, Australia,See McAuliffe v R HCA 37; 183CLR 108 and Miller v The Queen HCA 30 Trinidad and Tobago, the Solomon Islands, Texas, the International Criminal Court, and the International Criminal Tribunal for the former Yugoslavia.

Common design also applies in the law of tort. It is a different legal test from that which applies in the criminal law. The difference between common designs in the criminal law and the civil law was illustrated in NCB v Gamble 1 QB 11 at 23, by Devlin LJ:

The difference applies in US law as well. The United States Supreme Court reached the same conclusion in Sony Corporation of America v Universal City Studios Inc. 464 US 417 (1984). The supply of equipment for copying video cassettes did not give rise to joint liability in tort for copyright infringement. There was no encouragement to copy music and therefore no liability as an accessory. The difference lies between mere knowledge at the point of sale and action combined with common intention: Metro-Goldwyn-Mayer Studios Inc. v Grokster Ltd. 545 US 913 (2005): see p. 931. A different result was reached in Metro-Goldwyn-Mayer by the US Supreme Court. There was a common design there because the defendants "distribute[d] a device with the object of promoting its use to infringe copyright". That test was satisfied because clear statements and positive steps were taken by the administrators of the website to encourage infringement.

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 in R v Jogee that it was wrong, and that nothing less than intent to assist the crime would do.R v Jogee and Ruddock v The Queen UKSC 8 and UKPC 7 at UKSC website (retrieved 18 February 2016)

Jurisdictions

English law 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.

Until 2016, in cases where there is violence beyond the level anticipated, the prosecution had to prove:

In R v Jogee UKSC 8 the UK Supreme Court decided that (c) was wrong, and that the prosecution actually had to prove that D had intended to assist A to commit the crime, and this normally meant (but did not have to mean) that D intended A to commit the crime.

Deliberate departure Where one of the participants deliberately departs from the common purpose by doing something that was not authorised or agreed upon, that participant alone is liable for the consequences. In the situation exemplified in Davies v DPP AC 378, a group comes together for a fight or to commit a crime, and either the participant knows or does not know that one of the group has a weapon. If the person knows that there is a weapon, it is foreseeable that it might be used and the fact that the other participants do not instruct the one carrying to leave it behind means that its use must be within the scope of their intention. However, if the person does not know of the weapon, this is a deliberate departure from the common purpose and this breaks the enterprise.

When the outcome is death The simplest form of joint enterprise to murder is two or more planning to cause death and doing so. If all the parties participated in carrying out the plan, all are liable, regardless of who actually inflicted the fatal injury. However, when there is no plan to murder and one party kills while carrying out a plan to do something else, such as a planned robbery in which the participants hope to be able to get what they want without killing anyone, but one of them in fact kills, the other participants may still be guilty of murder or manslaughter if they had the necessary mens rea.

In R v Craig & Bentley (1953), Derek Bentley was hanged for the murder of a police officer, committed in the course of a burglary attempt. The murder was committed by a friend and accomplice of Bentley's, Christopher Craig, then aged 16. Bentley was convicted as a party to the murder, by English law principle of common criminal purpose "joint enterprise". The judge in court (Lord Chief Justice Goddard) sentenced Bentley to death based on an interpretation of the phrase "Let him have it" (Bentley's alleged instruction to Craig), describing Bentley as "mentally aiding the murder of Police Constable Sidney Miles". In 1998, Bentley received a posthumous pardon.

In R v Lovesey and Peterson (1969) 530 million. App. R. 461, a gang was executing a plan to overpower a jeweller and steal his more valuable stock. After the robbery, the jeweller was found dead. All were properly convicted of murder because the death was the outcome of the agreed use of violence. That this accidentally caused the jeweller's death did not prevent liability. The usual case will involve plans to commit criminal damage, burglary, rape or some other crime, and there will be no compelling inference that there must also have been a plan to kill. For the participants to be convicted of murder, the question becomes one of foresight that one of them might kill.

In R v Powell (Anthony) and English 1 AC 1, the House of Lords said that the other participants must have realised that, in the course of the joint enterprise, the primary party might kill with intent to do so or with intent to cause grievous bodily harm: with the intent necessary for murder. Thus, the Powell and English doctrine extends joint enterprise liability from the paradigm case of a plan to murder to the case of a plan to commit another offence in the course of which the possibility of a murder is foreseen (see R v Bryce. 2004).

In Attorney General's Reference (No. 3 of 2004) (2005) EWCA Crim 1882, the defendant, H, was charged with manslaughter. H had sent K and C to terrify R, knowing both that K and C would have a loaded firearm with them, and that this firearm might be fired near R to increase his fear. The Court of Appeal held that H's liability depended on the scope of the joint enterprise. On the assumed facts, there was no evidence that H foresaw that the gun would be fired and R might be injured. Rather, K's intentional act of firing the gun so as to kill or cause R grievous bodily harm was fundamentally different from the acts contemplated by H. The outcome would have been different if there had been a common design to cause some harm to R. In such a case, H would be liable for manslaughter because, albeit to frighten, he had authorised the firing of the gun: he would have realised that K might intentionally cause some harm when he fired the gun. However, on the assumed facts, H did not foresee the possibility of any harm to R, let alone intentional harm, so he was properly acquitted.

In R v Gnango UKSC 59, the Supreme Court held that D2 is guilty of the offence of murdering V if (1) D1 and D2 voluntarily engage in fighting each other, each intending to kill or cause grievous bodily harm to the other and each foreseeing that the other has the reciprocal intention, and if (2) D1 mistakenly kills V in the course of the fight. Baker argues that the case was wrongly decided because it did not rest on oblique intention, invoked joint-perpetration where there was none, invoked the "provocative act murder doctrine where it did not apply, and overly restricted the incidental party/victim rule without seeing that it did not apply because the actual victim as opposed to the putative victim (Gnango) did not consent to being harmed."

In R v Jogee UKSC 8, the Supreme Court decided that intent, not mere foresight, must be proved to convict an accomplice of a crime of specific intent, such as murder. The court said "foresight of what might happen is ordinarily no more than evidence from which a jury can infer the presence of a requisite intention. It may be strong evidence, but its adoption as a test for the mental element for murder in the case of a secondary party is a serious and anomalous departure from the basic rule, which results in over-extension of the law of murder."Paragraph 83 He summarised the law as: "If the crime requires a particular intent, D2 must intend ... to assist D1 to act with such intent."Paragraph 90 (This appeal was heard jointly with an appeal from Jamaica to the Judicial Committee of the Privy Council, with the same judges, Ruddock v The Queen UKPC 7.)

Repentance One person who has been an active member of a group with a common purpose may escape liability by withdrawing before the others go on to commit the crime. Mere repentance without any action, however, leaves the party liable. To be effective, the withdrawing party must actively seek to prevent the others from relying on what has been done. In R v Becerra (1975) 62 Crim. App. R. 212 it was held that any communication of withdrawal by the secondary party to the perpetrator must be such as to serve "unequivocal notice" upon the other party to the common purpose that, if he proceeds upon it, he does so without the further aid and assistance of the withdrawing party.: If an accomplice only advised or encouraged the principal to commit the crime, he must at least communicate his withdrawal to the other parties. Where an accomplice has supplied the principal with the means of committing the crime, the accomplice must arguably neutralise, or at least take all reasonable steps to neutralise, the aid he has given. In more serious cases, it may be that the only effective withdrawal is either physical intervention or calling in the police. In R v Rook (1997) Cr. App. R. 327, the court held that, as in the case of joint enterprise where both parties are present at the scene of the crime, it is not necessary for the prosecution to show that a secondary party who lends assistance or encouragement before the commission of the crime intended the victim to be killed, or to suffer serious injury, provided it was proved that he foresaw the event as a real or substantial risk and nonetheless lent his assistance.