What kind of society kills people, even after what they did, and whywould you want people to die? They have families who would be sad, but mabye we could torture them and let them go, it will teach them a lesson. If they die they will not learn, they need to learn to be good, besides they could help make the world a better place, and they would have kids and the world would have more people!
If you commit a harsh crime then you should be put to death. Instead of life in prison you should just go ahead and end your life with the death penalty. I don't think it's fair for a murderer to get a few years in jail for killing someone, while the victim is 6ft under.
A civilized, advanced society should not look to death as the ultimate punishment. How can we say killing is wrong, but kill in order to prevent killing? Society should practice what it preaches. An eye for an eye, they say, but an eye for an eye makes the whole world blind.