Historically in our criminal-justice system, two things must have been present for criminal liability to attach to an action. First, a person must have the intent to take the criminal action. Traditionally this culpable state of mind was called mens rea, Latin for guilty mind. The second requirement for criminal liability is actus reus, Latin for guilty act. The prohibited physical event must take place in combination with the requisite criminal intention for the actual commission of a crime to take place.