Mens rea (;
Latin for
"guilty mind") in
criminal law, is viewed as one of the necessary
elements of some
crimes. The standard
common law test of criminal
liability is usually expressed in the
Latin phrase,
actus reus non facit reum nisi mens sit rea, which means "the act is not culpable unless the mind is guilty". Thus, in
jurisdictions with
due process, there must be an
actus reus, or "guilty act", accompanied by some level of
mens rea to constitute the crime with which the defendant is charged (see the technical requirement of
concurrence). As a general rule, criminal liability does not attach to a person who merely acted with the absence of mental fault. The exception is
strict liability crimes.