But when you are executed, you have no chance to repent or to live for a better purpose. Death is too easy for murderers. In all actuality, the death penalty only exists for the compensation of the victims' families.
Have you not read the fine print which states that a life sentence without parole gives no one a chance to be normal?
Death for murderers is arguable better for everyone; victims' families get closure, tax payers don't have to pay stuff loads of money for sociopaths, etc.
Besides, they get a longer time in hell for what they did :).