In criminal law, what does the term 'actua reis' refer to?

The term 'actua reis' refers specifically to the voluntary physical act of committing a crime. In criminal law, for a person to be held liable for a criminal offense, there must be a demonstration of a physical act that is associated with the criminal behavior. This concept is essential because it establishes the presence of an action taken by an individual, which is necessary for determining guilt. Essentially, 'actua reis' underscores the principle that criminal liability requires both an act and a corresponding intent, thereby forming the basis for the crime.

In the context of the other choices, the mental state of the offender pertains to the subjective element of a crime, known as mens rea, but does not directly define 'actua reis'. The relationship between cause and effect, while relevant in discussions of liability and damages, does not capture the idea of the physical act. Lastly, legal justification deals with defenses to a crime rather than defining the act itself, thus it is not connected to the term 'actua reis'.