Thanks for your post and correction. Although I can’t instantaneously agree, I can assert the validity of the points you raise, and also say that I am pleasantly surprised about the underpinnings you give for your ideas. It’s really good rational reasoning in matters that inevitably come with lots of difficult emotions.
A&M
If you execute a person, there is always a chance that he was innocent of the crime he was executed for. If you imprison a violent killer, there is always a chance that he will kill again, either a guard, another prisoner, or somebody outside if he escapes.
My aim is to come to a trade-off which maximizes benefits for the law-abiding public. As such, for somebody who is accused of murder who has no prior history of violence, I would imprison him. But for somebody with a long, proven history of violence, he has demonstrated beyond doubt that he is a danger as long as he lives, and thus society would benefit from his execution, even considering the possibility that he is innocent of the crime he's accused of.