This is an age old question, are people born evil or do they become evil over time?
As a kid I grew up a half a mile from my uncle, he had a German Shepherd fenced in behind his house. The dogs name was Wolfy, that dog scared the shit out of me growing up. I was terrified of it, we had to walk by the house on the way to the school bus stop which was a mile from the house and every morning, Wolfy was waiting by his fence, his white snarling teeth protruding from gap in the fence as he barked and tore at the fence trying to get to us.
I found out later in life, that my uncle had rescued Wolfy from an abusive person and they had kids that tortured that poor dog. I came to realize that the dog was scarred by his abuse at the hands of kids and every time that he saw us coming near his house it likely got him scared, hence he tried to get to us. Wolfy wasn't born a bad dog, I am sure he was a happy little pup when he was born and he probably frolicked around the world lovingly until his innocence was shattered by the cruelty of bad humans.
I don't believe that people are born evil, I think humans have a great capacity to be good or to be evil. There are two extremes, some people can choose to be like Hitler, others can choose to be like Mother Theresa. Ultimately it's the choices we make in life that define who we are and who we are to become.
I believe that everyone is redeemable up until the moment of their deaths, and yes, even Hitler, Stalin, and the other mass murderers that have ravaged the world.