Legal maxim and Latin for the act does not make one guilty unless there is a criminal intent. To be guilty of a crime under criminal law requires two elements, a guilty act (actus reus) and a guilty state of mind (mens rea). Without a guilty mind or criminal intent there is no crime. (In general this is true, except for strict liability statutes such as speed limits, for example, which are violations.) The act itself does not make a man guilty, unless his intention be so. There must be a vicious will or criminal intention as well as an unlawful act. Where one engaged in doing a lawful act. without any wrongful intention, unfortunately and inadvertently kills another person, the homicide is excusable.