And the martial arts wow depends on the case; I have only been in knife fights were the knife was pulled by a drunk guy. No problem taking that away. I would imagine this is often the case; depending on the drug it would not be hard, especially with a baton in hand. No guns needed.
The stories I read here today, in the article and generally in the EU press about US shootings just show shoddy police work though. But that's because it's press; they don't really want to publish things that go well; only things that go bad.
> trying to hit anything other than the torso under these conditions (especially if the target is moving, or any real distance away) while your heart is pounding and your hands are shaking is very very difficult.
Real distance away? Talking about someone coming at you with a knife in hand...
Moving => yes but towards you and I would like to bet most (by far) people will run at you in a straight line when attacking.
But yes, of course, if you fear for your or someone else's life, you would shoot to kill. My whole point is that in the US it seems (i'm being careful here not to go with all public opinion :) police is far to trigger happy also in cases were it makes no sense at all.
Edit: also if you read 'ajuc' his comment about Poland (and it's the same in NL and DE and probably the rest of EU); you have to shoot at the legs first. It's how we are raised to think and when there are police shootings here often (mostly) people are just wounded.
You've been reading too much Martial Arts Wow literature. Taking a knife off someone is highly likely to get you cut, badly. Police don't aim for 'non lethal' parts of the body, because if you're using the gun, your life is being threatened, and you are using deadly force already - trying to hit anything other than the torso under these conditions (especially if the target is moving, or any real distance away) while your heart is pounding and your hands are shaking is very very difficult.