i think law reinforcement in america of american citizens, last time i checked does not use the doctrine of shoot to kill on site.
Law enforcement wouldn't be stupid enough to use a doctrine of shoot to kill on site, but in some cases that is what they have. Today's police in the US aren't trained as they were 40 or 50 years ago, today if they pull their gun and start shooting they are more than likely going to empty their weapon into the victim. A friend who I have known since I was two and is a retired CA CHP has told me they were trained to first of all avoid using deadly force unless it was absolutely necessary and if they had to shoot they were trained to shoot until the person was no threat. He says today's officers are basically trained to shoot until their weapon is empty or they run out of bullets. He says at that point they are no longer police officers, they are executioners. The doctrine of shoot to kill on site isn't a defacto doctrine but it is there.