Big difference between being mean and physically abusive. I don't know anything about his childhood to form an opinion. But I know first hand what a ****** childhood can do for you. And yet again I haven't killed anyone. Like it is said you always have choices. I do want to say that you can put yourself in bad situations with bad early influences. So I sympathize with anyone that was brought up in difficult situations.
And another thing, how did Hernandez's brother turn out to be a good, seemingly stable guy? I didn't hear any talk in that documentary about the father senselessly beating them or anything like that, unless I missed it (which is possible, I'm just under the assumption that he was a mean drunk).