I find his mental illness interesting, assuming he was a psychopath. Does this mean he was responsible for what he did? I don't know, but certainly when he wanted to go back to prison, he wasn't allowed. I think he also got medication.
But he was considered sane enough to stand trial, but I suppose he was quite intelligent.
It's similar to Peter Sutcliffe, I suppose. I can also understand why people say, sod psychiatry, hang the bastards, although the law presumably would not allow that, if they are judged insane.
Actually, I just noticed that Sutcliffe was moved back to prison, so presumably was judged sane enough.