Justice. When you murder someone, your life is forfeit. Anything less is an insult to the victim.
Or retribution hiding behind justice.
From
Wiki:
Revenge is a harmful action against a person or group in response to a grievance, be it real or perceived. It is also called retribution, retaliation, vengeance, or veiled as justice.
-bold emphasis mine.
I'm not going to bore you with lengthy arguments that are pretty standard and readily available many places online, including my Wiki link, but I will briefly touch on a few highlights.
Scientifically speaking, studies in the last couple decades seem to indicate that deterrence is less dependent on the severity of the punishment than was previously thought. It may be that as the certainty of getting apprehended and put away for life
(for real) goes up with a concurrent reduction in error rate
(hence less successful appeals) we'll see an overall drop in murder rates - yet to be conclusively proven in a societal setting, granted. Recursive modelling seems to point in this direction though. Have you been exposed to any of these studies? I can provide some additional links if you so desire...
In addition we must be willing to objectively accept a certain error rate if we continue to utilize capital punishment - i.e. we must accept that we are killing 1 innocent person for every 100, 1,000, or 10,000 guilty parties executed. This fact can not be ignored, as recent forensic DNA analysis applied to reviews of previous convictions has shown. This is where the finality of death comes in - while we may drastically reduce the quality of someones life experiences through mistaken imprisonment, we at least mitigate the finality inherent in capital punishment and leave the door open for some rectification if the initial conviction is later vacated.
What is your take on acceptable collateral damages here? One innocent's death for how many guilty, just so that we can assuage the victims relatives desire for vengeance?
Finally, a completely different take on the matter which may be very relevant to some people. In the Abrahamic religions, many believe that their holy books tell them that capital punishment is just, fair and even necessary. On the other hand, most if not all relevant passages can be and are interpreted in a completely different light - not to mention many which are directly contradicted elsewhere in the same text.
For example, an eye for an eye, a tooth for a tooth - is this meant to demand "equal" retribution to obtain justice, or does it proscribe exceeding equivalent damages in pursuit of said justice? Many believe the second interpretation is the more accurate - take
no more than a tooth for a tooth or an eye for an eye. While this may seem to allow for execution by the state (or the victim's family, for that matter), we also have "vengeance is mine, sayeth the Lord". Hmmm... And so forth. The first interpretation has led to many a never ending blood feud over the centuries, with each side retaliating for past wrongs over and over again - to the point that neither even remembers the particulars of the original transgression. Hardly productive, eh? Of course we also have "Forgive us our trespasses as we forgive the trespasses of others", etc., etc., - ad nauseam.
While I am not nearly as familiar with the Q'uran as I am the Christian Bible (and thereby to a lesser extent the Torah), my understanding is that while a case for permitting revenge may be more easily made under some Islamic belief systems, a peaceful solution is still preferred. Although I was raised Baptist I have come to be ignostic over the years, therefore I do not claim any particular expertise on religious matters, so I ask you: Do these observations square with your interpretation(s)?
Personally, I am comfortable with the scientific and economic reasoning and have, as I mentioned, changed my stance one hundred eighty degrees over the decades - I was an advocate of capital punishment, now I am not. I state this again to preclude any suggestion that this may just be all rote to me. I'm hardly a pacifist and firmly believe in the right to take a life in order to prevent someone from killing me or mine - whether that be during a home invasion or wartime - the difference being that it happens during or just before violence is perpetrated by someone else. Not fifteen years after the fact. So, while a desire for vengeance on the part of a murder victim's family and friends is certainly understandable and to be expected, I no longer support state sanctioned capital "punishment", mainly for the purely pragmatic reasons outlined above.
