Presumption of culpable mental state: court presumes mens rea but accused may prove its absence as a defence. Court shall presume existence of a culpable mental state in prosecutions under the Act where such state is an element, but the accused may rely on a defence by proving absence of that mental state with respect to the charged act. 'Culpable mental state' includes intention, motive, knowledge of a fact, and belief in, or reason to believe, a fact; facts are proved only when the court believes them beyond reasonable doubt.