Evil is not something a person can be, though they may partake in evil acts in one way or another.
Evil does exist out there and seem to arise by itself, but no plant is without root; there are causes and conditions that lead to evil decisions.
We see evil everywhere we look for it.
So, we can talk all day about the evil one person or group of people did, but when we try to talk about who is evil as an innate quality, it falls apart. If you were raised in Japan leading into WW2, you would've gotten swept up in the war whether you were willing or not. Does that make you evil, or did you just make a series of choices given the world that stood before you. Maybe some of those choices could be considered evil, so it's up to your own beliefs how you will be judged.
It's really sad to see us still trying to paint with such broad strokes.