In addition, show me a list of murderers who have truly benefited from prison sentences and added something of value to society?
If you kill someone premeditated then you should spend the rest of your life in prison. If you killed someone by self defense then many factors would have to be taken into consideration. Just because you killed someone that entered your house without your permission and was waving a weapon around doesn't mean you have to kill them. If it's a baseball bat for instance then he not likely to kill you with it and you wouldn't have to use lethal force either. It almost all self defense cases there was a better option.
"It doesn't matter if they re offend or not" - Really? You don't care how many innocent people get killed? In addition, sending murderers to prison leaves a breeding ground for more murderers and murders (as I've explained above). Furthermore, I don't know why you bring this into the equation: "If you kill someone premeditated then you should spend the rest of your life in prison. If you killed someone by self defense then many factors would have to be taken into consideration. Just because you killed someone that entered your house without your permission and was waving a weapon around doesn't mean you have to kill them. If it's a baseball bat for instance then he not likely to kill you with it and you wouldn't have to use lethal force either. It almost all self defense cases there was a better option", I am not the one having trouble to differentiate between murder and a justified killing.
In addition, capital punishment does serve as a deterrent to at least some level despite the skewed manner in which statistics are abused in this regard. Marxists always need a general crime wave in order to wage war against their enemies. They are too cowardly to declare it openly and fight like men.
Again, "show me a list of murderers who have truly benefited from prison sentences and added something of value to society?"