The less the ability to create death is exercised by a government, the less it will be present in its people.
Families of victims are no more prepared to deal with the effects of a crime when its alleged perpetrator is killed than when he or she is sentenced to life without parole (LWP).
Capital punishment costs significantly more than life without parole due to paperwork costs.
The court system is not perfect; a certain number of those sentenced the death penalty are innocent. If sentenced to LWP, these people can be released once their innocence is ascertained.
The death penalty in the US is sentenced disproportionately more to crimes caused by minorities to white people.
http://www.amnesty.org/en/library/asset/ACT50/010/2007/en/f45ed09c-d3a2-...