(Collinsville, IL)  —  The Major Case Squad is investigating a murder in Collinsville.  A Belleville man was shot and killed there Saturday.  Collinsville Police responded to the scene just after noon on Saturday and found 21-year-old Montrea Marshall outside of an apartment on South Morrison.  Marshall was taken to Anderson Hospital and pronounced dead.  The Major Case Squad of Greater St. Louis was called to handle the case, and investigators believe that Marshall knew his killer.  The suspect fled the scene in a white Chevy Cruze or similar vehicle.  Anyone with information is asked to contact the Major Case Squad at 344-2131 or Crimestoppers at 866-371-8477.