Well if I shoot three, wouldn't I just be better off killing the fourth? I'm serious here. I think you'd be even worse off with Tyrone taking the stand talking about how you shot his best friends "the aspiring athletes, honor students who were just on their way to his Auntie's house" when you started blasting.
And I would hope you follow the advice given in my carry class, to always have a recording device running on your belt when you are out in public.
What about two-party consent states for audio recording? I think I would move to Vermont before I started carrying a Batman utility belt (cellphone,pistol, recorder) anyway.
Yes, some states have two party consent. But there may be exceptions for recording in public places and there may be some case law that allows such evidence in self defense cases.