With regard to the death row inmate who murdered his wife and children, Trevor didn't ask him why he did it. Usually, people who kill their spouses and their children also kill themselves.
Yeah, he was the only one who unnerved me [the rest seemed human and remorseful - albeit, some were aware that prison was the best place for them]. Not a mention of his family he murdered, and Trevor didn't ask him why he did it.
I was like 'Really...?' I mean, perhaps his whole 'cleaning' kick is merely to avoid thinking about it at all, but still. Wtf.