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." He summarised the law as: "If the crime requires a particular intent, D2 must intend ... to assist D1 to act with such intent." (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 [2016] 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.