I'll admit that the evidence is... circumstantial. His previous warden was a friend of Dean's, and there was a rash of incidents around the same time, all involving friends of hers... [He gives her a look like, hey, probably something you should know anyway.]

He had the means and the opportunity, and he was the only one to whom we could attribute a motive who could have been in all those places at those times. It's not hard evidence, no, but four of us investigated and all came to the same conclusion.