The Asian gang members often mark the back of hand with 3 tattoo dots or 3 cigarette. Hispanic gangs also use a three dot tattoo which may have several meanings; one which may be "Mi Vida Loca" or My Crazy Life. Another may be representative of the "Los Vatos Locos" (The Crazy Dudes or Guys) gang. Hope you fine this helpful. The link I listed in source has quite a bit of information on gang tattoos and marks.