More likely he's trying to think that killing Terri might not be the best way to escape his past actions. If he turns Terri over to her parents, that action might make him look like enough of a good guy to prevent anyone from trying to pin attempted murder charges on him. By contrast, even if he succeeds at killing Terri, there's enough attention on this case that he might not be able to escape prosecution. And a jury with even half the facts in this case could very easily find him guilty of Murder One if not Capital Murder (what are the requirements for a death sentence?)
Let's not forget that voters are now energized, empowered and pro-active. It's not like the old days. Tom Daschle thought he'd be there as long as HE wanted, too. I'm assuming Judge Greer stands for election .. am I correct?