Madison police have arrested a suspect in a Wednesday night shooting which left a 24-year-old victim in extremely critical condition with a head wound.  Police say the shooting happened during a conflict between two men who know each other.  No names have been released.  Witnesses told investigators the accused shooter ran from the area and tried to steal a vehicle so he could get away.  Officers found him hiding in a maintenance room of a nearby apartment building.  No weapon has been recovered.  The shooting suspect was taken to a hospital for treatment of cuts he apparently suffered during a fight.