Elements of a crime What is a crime? Almost every crime has 4 basic elements.. 1. Prohibited Act- Actus Reus. The law does not punish people for having criminal thoughts alone, there must be an act. 2. Criminal Intent- Mens Rea guilty mind, can be the most difficult to prove. 3. Concurrence of the Act and The Intent- the person has to intend the act when he or she commits it. 4. Causation- The act has to cause the harmful result