(The coincidence of actus reus and mens rea)
It is a principle of English law that the actus reus and mens rea must coincide. That is they must happen at the same time. This is sometimes referred to as the contemporaneity rule or the coincidence of actus reus and mens rea. However, the courts often apply a flexible approach in holding that the actus reus is a continuing act.
Thabo-Meli v R  1 WLR 228 Privy Council
The four appellants were convicted of murder. They had planned to kill a man and then make it look like an accident. They took him to a hut and beat him over the head. Believing that he was dead, they then took his body to a cliff and threw it off. Medical evidence showed that the deceased died from exposure of being left at the bottom of the cliff and not from the blow to the head. They appealed against their convictions on the grounds that the actus reus and mens rea of the crime did not coincide. That is to say when they formed the intention to kill, there was no actus reus as the man was still alive. When they threw him off the cliff, there was no mens rea as they can intend to kill someone they believed was already dead. Held:Convictions upheld. The act of beating him and throwing him off the cliff was one continuing act. Lord Reid:
"It appears to their Lordships impossible to divide up what was really one transaction in this way. There is no doubt that the accused set out to do all these acts in order to achieve their plan and as parts of their plan; and it is much too refined a ground of judgment to say that, because they were under a misapprehension at one stage and thought that their guilty purpose and been achieved before in fact it was achieved, therefore they are to escape the penalties of the law." Fagan v MPC  1 QB 439
A policeman was directing the defendant to park his car. The defendant accidentally drove onto the policeman's foot. The policeman shouted at him to get off. The defendant refused...