The individual was a prisoner (under state law) whose sentence was about to expire but who was alleged to have made threats against the safety of various persons, to be carried out when released. The State Parliament enacted a law, applying only to him, which authorised the Supreme Court of New South Wales to make "preventive detention orders" for periods up to six months, with the possibility of renewal. The orders were to be made if the Court was satisfied, "on the balance of probabilities", that the person to whom the Act applied was "more likely than not to commit a serious act of violence".