@Mallymkun
With regards to the deterrence effect of the death penalty - There's no real evidence it does anything.
Originally Posted by National Research Council
Most researchers have used post-Gregg data from the United States to examine the statistical association between homicide rates and the legal status, the actual implementation of the death penalty, or both. The studies have reached widely varying, even contradictory, conclusions. Some studies conclude that executions save large numbers of lives; others conclude that executions actually increase homicides; and still others conclude that executions have no effect on homicide rates
Taken from
here.
Additionally, just run through your head why people kill/rape. It's not often a cold/calculating weighing up of the pros and cons, of incentives and deterrences (and for those who do, they tend to think they're smart enough to not get caught). Usually, there's intense emotions involved. Consequences get pushed aside until after the act.
All that aside, wouldn't you agree that the tradition of retributive punishment is a little bit outdated? Eye for an eye? Bit biblical for my liking. Do you believe in free will? How much of what you do is really under your control? How much of it is a result of your upbringing and your brain chemistry? Have you heard of determinism? You have no choice but to act as you do. Rapists rape and Ele preaches. Lion's gonna lion. Do we kill all lions? If we have no choice in things, as I believe, then capital punishment seems barbaric as fuck. Certainly doesn't seem moral.