First of all, I wouldn't dare insult you and say I know how you feel. I detest guns and hate what they can do in the hands of the wrong people. I will say I'm glad you recovered from your ordeal, at least physically.
Now I'm about to say something I NEVER thought I'd tell someone on this forum but feel it needs discussing:
You have related to the officer in question in an illogical and overemotional way. You have allowed your experiences to cloud your judgement and can in no way see past the blatantly obvious fact that this officer did not use appropriate procedure and may have killed someone unnecessarily. It must be difficult to deal with this situation because of your personal experience, but in the end, he's going to be judged by departmental procedure and possibly a jury of his peers.
You said that the perp shouldn't have been fighting in the first place; I'll go as far to say that you're right. But without crime there would be no need for police and in society, that's just not going to happen. The perp is the layperson-they do not have academy training and hours of classroom instruction at their disposal, but the police officer does.
If I could use another scenario to further show the lack of logic here (lack of logic-ha, I wish my favorites at P & R could see me now!-But I digress). If a doctor commits malpractice, who's at fault? Is it the fault of the patient who shouldn't have gotten sick in the first place? Or is it the responsibility of the trained professional to work in the parameters of his/her training?