Presumption of culpable mental state shifts evidentiary posture, allowing accused to rebut while facts require proof beyond reasonable doubt. The amendment creates a rebuttable statutory presumption that a required culpable mental state (including intention, motive, knowledge or belief) exists in prosecutions under the Act, while allowing the accused to establish that he lacked such a state as a defence; it further provides that a fact is proved only when believed to exist beyond reasonable doubt, not by mere preponderance of probability.