 Among those at Sunday's meeting were Sgt. Michael Neal, the Wellston police officer whose 11-year-old son w as slain three weeks ago; 15-year-old Bill Wilke of Maryland Heights, who was seriously wounded in a shooting two years ago; and Jeanette Culpepper of St. Louis, who lost a son to gun violence.  ''People are already crazy; we're already cuckoo,'' said Culpepper, who heads a group called Families Advocating Safe Streets. ''What this does is allow me to take matters into my own hands; I don't care how you dress it up.'' Neal said Sunday that he would leave the police force if the proposal becomes law.  