Authorizing law enforcement agencies to sell forfeited firearms, ammunition and firearms accessories to federally licensed firearms dealers, to sell antique firearms to the public and to destroy or use for law enforcement purposes semiautomatic military style assault weapons, providing for the distribution of proceeds from the sales; prohibiting the Hennepin or Ramsey county sheriff from selling firearms, ammunition or firearm accessories upon disapproval by the respective county board (Ch. 148, 1999)