I am a retired LEO, and, IMHO and based upon countless conversations with lawyers over the years, I believe that a person in this scenario must really answer the following questions: Did you act reasonably, responsibly with prudence and common sense? Would most God fearing, honest, law-abiding citizens act in a similar fasion? It really boils down to common sense. A person must demonstrate by his/her actions that they took a reasonable response to a situation, and that it was not exploited to use deadly force. I cannot imagine that in any law enforcement jurisdiction (local, state or federal) that a person would not be found innocent in such a situation. Like many of the other posts have said, you might have your weapon confiscated for a brief period of time to thoroughly document the circumstances, but I seriously doubt that you would ever be charged with the violation of any law. In any potential deadly encounter situation, I think the main issue is to not to appear to be or have been a "cowboy." I realize that some people simply do not want to get involved in a situatioin like this for fear of being sued later by the BG's family, etc., but, personally, I could not just stand by and watch someone killed or injured without taking some action. I grew up watching the old westerns and John Wayne, and I guess I believe that if you always do the right thing, things will turn out right. Probably very naive of me, but that is the way I live my life. I don't want to hurt anyone, but I will NEVER be a passive victim. Just my thougts.