One thing that they drilled into us during our use of force training was something called The Reasonable Man Standard. People are always going to feel like they had no other choice or that they were right to do whatever evil thing they do. You have to look at the situation from outside of your own perspective and think, "If this were on TV, would I look like a bad guy?"
Basically, if a "Reasonable Man" would think to himself, "If I were in his shoes, I would have probably done the same thing...." then chances are that you were justified. And not just one reasonable man, either. The general population. If I, a 200lb+, muscular looking, guy with some serious training felt threatened by a 100 pound woman and I felt I had to punch her in the face or shoot her, I had damn well better have a good reason. Maybe I thought she was a trained ninja or something. If, from a general perspective, I had other options, then I'm screwed.
A couple of key phrases are: "The totality of the situation" and "What you can articulate in court" because those are the two things that are going to decide if you were right or wrong. If I can tell a good enough story in court so that people see things from my point of view, I'm innocent. If I'm not as good at getting my point across and people see me as a monster, it's game over, man. The individual will always feel they were righteous and innocent. But this sonuva bitch killed like 80 people in self defense!! What reasonable man would see things from his point of view? Marcus Fenix?
*edit* Of course, this wasn't in the U.S. so nothing I said applies, I guess.
