Surveyor: Your situation has been hashed over in many advanced tactical classes that I have either attended or was giving. The best solution IMHO that was advanced is to: IF your situational awareness tells you that someone in your vicinity MIGHT be a threat; move to the best tactical position available to you at that time and place; move any others with you to the best defensive position for them; unobtrusively draw your handgun and conceal it behind your hip; watch the potential threat person very closely; have your other people watching for other potential threat people while keeping you informed of same; when the potential threat person is within 20 to 25 ft. from you verbally order him to STOP and not to come any nearer; IF that person stops, warn them to leave; IF that person does not stop, bring your handgun to your preferred two handed hold at a 'ready' position; watch that person's hands very closely; warn that person again to STOP; If complied with tell that person to leave NOW; any display of any weapon whatsoever, shoot. Now be the first to call the local Police. If the threat person leaves before seeing your handgun, just unobtrusively re-holster ........... Big Cholla