Crime is an act or omission which is prohibited by law and is followed by sanctions. It works on the maxim actus non facit reum nisi mens sit rea which means “an act does not constitute to a crime unless done with guilty intent”. For an act to constitute a crime there must be some wrongful act/omission combined with a guilty or wrongful intention. Any act does not become a crime if it lacks in the required guilty intent of doing so. This gives us two essentials of a crime. These are – Actus Reus and Mens Rea. We will look into these terms separately.
Constituents of Crime = Actus Reus (wrongful act) + Mens rea (wrongful intention)
Where the law requires us to act in a certain way for example, a parent is required to care for her child, a failure to act will violate the law. Actus Reus includes only voluntary bodily movements, particularly one which society has an interest in preventing. It is to be noted that not only the acts but the omission of doing an act, which the person is supposed to do, will also amount to Actus Reus. It generally arises out of a duty. For Example, as per section 19 of The Police Act, 1861, the special police officer cannot refuse to serve his duty without sufficient cause. Here the act or omission on part of the officer will result in criminal liability.
The following principles are also considered while determining an Actus Reus in a crime –
It may be possible that instead of depending on a single act or omission, the act is a result of a number of factors. Section 33 of the IPC recognizes act/omission not only as a single act/omission but as a series of acts or acts/omissions also. If a factor is responsible for constituting an offense in such a way that without it the event would not have happened then that factor will be taken as a cause of that event.
For example – A shoots B and as a result, B was wounded on the leg. Because of this wound, B is unable to keep his balance and falls in the river. He does not know how to swim and therefore dies. In this case, A did not directly cause B’s death but it happened as a result of shooting B on his leg. Had A not shot B on his leg, he would not have lost his balance and hence, would not have fallen into the river and died.
It is to be noted that if the cause and effect of the action are too remote then the person will not be held liable. This takes us to the next principle called the principle of reasonable foresight.
PRINCIPLE OF REASONABLE FORESIGHT –
As per the Principle of reasonable foresight, a man will be held liable for his action which he could have reasonably foreseen. The consequences of his action should have been reasonably intended. Here, the consequences should not be too remote.
For example – A by negligence hit B’s car. B was fatally injured and was lying on the road. A passer got a brain shock after seeing the incident. A is not liable for the passer-by’s Bain shock, as any reasonable and prudent man would not have foreseen such a case.
PRINCIPLE OF ORDINARY HAZARD –
In this principle, the act of the person would amount to crime if it is hazardous enough to cause harm. For example – A intended to stab B but missed it, later on, B dies because of an accident. In this case, the act of attempting to stab B is hazardous enough to constitute a crime. Therefore, A will be liable for this attempt.
UNEXPECTED INTERVENTIONS –
There may be circumstances wherein the action of committing a crime may be intervened. In these cases, the liability is decided by the stage at which the intervention took place.
For example- A mixed poison in the water to kill his wife. He left that poised water in the kitchen to give it to his wife later. His wife woke up early and drank the poison. In this case, A will not be liable for an attempt to murder.
- P S A Pillai’s Criminal Law, LexisNexis, 2019
 Michael Corrado, Is There An Act Requirement in the Criminal Law? Vol. 142:1529, UNIVERSITY OF PENNSYLVANIA LAW REVIEW, 1529, 4, (1994).
 Powell v. Texas, 392 U.S. 514 (1968)