This case raises an internal moral conflict that I'm neither used to feeling nor comfortable with. I'm very grateful that I wasn't on that jury. It isn't my place to hold another person's life in my hands.
While I commend you for your analytical thought process of elimination based upon moral prejudice, I feel you should be reminded... It wasn't his place to hold other's lives (and death) at his hands, but he was perfectly fine with that moral conflict, without second guessing.
That being said, I would prefer to see him used for science experiments, rather than sit in a jail or quickly executed. A high energy laser test session comes to mind... =p