This is an old post, but I would still like to make a reply to your comment. I will state that I am very much a 2nd Amendment supporter.

Outside of shooting someone in an official capacity (Military, Police etc.), yes I did leave out Militia because that gets into a very political aspect of what each person considers what is right and what is wrong. I personally don't look at it from the stand point of being Judge, Jury and Executioner. The reason I don't is that the combination of those 3 terms implies very much forethought in the action of killing someone. So from the perspective of a civilian killing another person, this should only be done in Defense of Self, Family or Others (which in any scenario I can think of) this would happen in a spur of the moment type of situation i.e. someone breaks into home, someone pulls a gun on me etc. These scenarios would not be preplanned from my side, therefore there is no forethought of any action taken beyond the mere seconds or few minutes of the scenario.

There was a reply about tracking someone down that has actively tried to harm you or your family, to me this is very tricky because I have always believed that the best offense is a good defense, so ignoring the legality portion, morally I would prefer to exhaust all options before resorting to such a drastic measure (though I could never rule it out). Which, by the way, I would be remiss if I didn't point out that this would be the 1 scenario which would become Judge, Jury and Executioner.

Now in regards to the sanctity of life part of your reply, I personally would prefer to never take a life, BUT I will not sacrifice mine or others (close to me) to avoid doing so. Also, if there is ever a situation where I would mount a defense, I believe in doing it full force. I have heard people state in the past that they would aim for an arm or a leg to wound not kill. To me attempting to wound versus kill leaves the person defending themselves in just as much danger (the threat must be completely neutralized)!