Uh, no they shouldn't let him out.
He's a crazed mad man and because of him there are- what? 8 people dead. And what were there? 6 people he influenced to actually commit these murders for him? Nuh-uh, let the crazed goof rot in hell.
Stickler is if it wasn't for the dealth penalty being repealed he'd probably be dead by now. It's a shame they never changed the law to include those who were previously convicted, like Manson, who do deserve the death penalty.