The purpose of this Article is to levy an excise tax to generate revenue for State and local law enforcement agencies and for the General Fund. Nothing in this Article may in any manner provide immunity from criminal prosecution for a person who possesses an illegal substance. (1989, c. 772, s. 1; 1995, c. 340, s. 1; 1997-292, s. 1; 1998-98, s. 59.)