EDIT:
Which is to say, the bar is usually something like reasonable belief that your life or the life of someone present is in imminent danger.
There's also the infamous case of the FL woman who initially received a 20 year sentence for firing warning shots at her estranged husband. She won a new trial on appeal, so we'll see how that turns out.
http://usnews.nbcnews.com/_news/2014/01/10/22255312-florida-...
It's definitely unfortunate that it works out like that, but using a firearm in any sort of aggressive manner is deadly force legally, and you better be well and sure you're justified in doing so or you're going to be in a world of hurt with your local prosecutor.
I'm losing any desire to go to USA. Not just working, even visiting. Even if the chances of events such as this happening are relatively low (?), why risk it? I do not like idea of being raped by police and doctors and getting the bill [1].
I'm just wondering how can this be real. Where's the punchline?
[1]: http://www.conservativeactionalerts.com/2013/11/police-abuse...