[Blink]

No matter what happens in the world, there will always be at least one person who wants to kill someone else. It doesn't really matter if the person is mentally ill or demented, if they want to kill they will try to find a way.

That's actually a pretty large generalization. Someone could want to kill someone, but is afraid of the potential consequences and thus doesn't, or maybe one could be somehow unable to (idk, what if you're a blind, deaf, and psychotic). Just because someone wants to kill, doesn't mean they will find a way, or even try.

Although your overall point is fine.