In a civil or administrative proceeding brought under this Chapter, the burden of proving an exemption or an exception from a definition is upon the person claiming it. In a criminal proceeding brought under this Chapter, the State has no initial burden of producing evidence to show that the defendant's actions do not fall within the exemption or exceptions; however, once the defendant introduces evidence to show that his conduct is within the exemption or exception, the burden of persuading the trier of fact that the exemption or exception does not apply falls upon the State. (1987 (Reg. Sess., 1988), c. 1098, s. 1.)