I noticed watching an episode he was carrying his personal Gunsite 1911. I read he bought it there while taking a training course.
This is apparently true. He's a huge fan of the 1911 platform, and even though in the Robert Parker books Jesse Stone used a .38 special revolver, or if expecting real trouble a 9mm Browning high power, Tom changed it around to a 1911. While still alive, Robert Parker and Tom Selleck became good friends and Parker was okay with the change.
Carl.