I understand your reasoning exactly, Sal, but there's another side, we know there is no such thing as a secure prison, a few even escaped from Alcatraz, that was supposedly impossible to escape from, so there is no way we can guarantee a living criminal will not reoffend. God forbid but some day Paul Bernardo or someone of his ilk is going to escape which will almost certainly result in the loss of more life.
Check the US and secure prisons- and how they drive the prisoners to become more dangerous.
You want perfection from a system designed by man.