I really liked the idea, but I felt like the episode was really flawed. A man with an IQ of 180 would have been extra careful in his murdering of his first wife and had her body cremated, too. There's no chance he'd leave the body, especially if he was planning on killing in the same way again. (actually, it's more likely that he would have come up with another way to kill his 2nd wife... i'm sure he's smart enough)
And quite honestly, I didn't really buy it. Patrick Kloster did not seem like a man with an extremely high IQ. Even if he was good at chess, a man with such a brain would not devote his life to playing chess.