It's not so much about the documentary but about the issues raised.
He beat to death his wife and the mother of his children.
He appeared to have hated her constantly put her down said she was a dreadful mother ect, also seemed to be quite resentful of his parents-in-law and was having an affair.
What causes the complete lack of insight into himself and the complete lack of empathy and also the belief he would get away with it?
is it a personality disorder? is it evil? ( not a belief in the devil sort of evil ).