What term is used to refer to the body of the crime and its necessary elements for proof?

The term that refers to the body of the crime and its necessary elements for proof is "corpus delicti." In legal contexts, corpus delicti translates to "body of the crime," and it encompasses the essential facts that establish that a crime has occurred. To successfully prosecute a crime, the prosecution must demonstrate that a specific crime was committed and that there is a relationship between the crime and the defendant.

For instance, in cases of homicide, corpus delicti would require evidence that a person has died and that such death resulted from a criminal act. This principle is fundamental in criminal law, as it prevents someone from being convicted of a crime merely based on a confession or testimony without physical evidence supporting the occurrence of the crime itself.

The other terms mentioned in the choices have different legal meanings. Mens rea, for example, refers to the mental state or intent of the person committing the crime, while actus reus refers to the actual act or conduct that constitutes a criminal offense. Habeas corpus is a legal principle that allows individuals to seek relief from unlawful detention. Each of these concepts is important in the legal framework but does not directly define the body of the crime like corpus delicti.