TN law states that you have the right to defend yourself with deadly force if you are in fear of death or serious bodily harm. You are not obligated to retreat first. If someone charges you with a knife you could taser him, use a baton or run but he still might cut you, I personally would eliminate the threat with two to the chest and take my chances in court. One might say you should run but what if you trip. one might say you should of tasered him or used pepper spray, but what they had no effect. There are to many variables that come into play. If I'm in fear enough to use pepper spray, a taser or a baton then the situation warrants bullets. Thats just my opinion though.