Definition of the crime, also known as criminal offense, is the legal definition of an illegal act or omission. It is the basis for the criminal justice system to be able to determine what constitutes a crime and assign a punishment for it. There are two main types of definition of crime: substantive and procedural. Substantive definition of crime refers to the elements of a crime that must be proven beyond a reasonable doubt in someone to be found guilty. This includes the elements of the crime such as the actus reus (the guilty act) and mens rea (the criminal mind). Procedural definition of crime refers to the laws that determine how crimes are investigated, charged, and punished. Examples include criminal statutes, sentencing laws, and civil procedures.