All civilized societies disallow murder if they wish to model behavior against murder.
That said; let us look at some facts. In the USA, in 2009, approximately 15,000 murders were committed, that is of those we know about. Also in 2009, there were less than 50 death penalty convictions, and subsequent executions. Is it logical, that these fifty state supported murders deterred, the other more than 15,000 criminal murders committed that year? Is it logical, that in the adrenalin surge, passion, or drug-induced stupor the suspected criminal was in, that he stopped to consider, (or even knew of) those forty or so state sponsored executions?
Here is another factoid, to consider. The death penalty is applied in 34 states. If you committed murder, wouldn’t it be easier to cross a state line, then risk sitting on death row? Currently, we reside in Hawaii. This state has far fewer murders committed than many of those states with the death penalty still on the books. Yet, we can never know for sure whether it is the calming swaying palms, or the lack of a death penalty, that deters murders here.
These are only some of the significant number of inconvenient facts surrounding the unfairness of the death penalty. Others include the fact that DNA evidence can and has, exonerated many suspected murders. And, there are a great number of disproportionate minority executions in relation to number of corresponding crimes.
If, in a perfect world, all murderers faced murder themselves, albeit not everyone’s view of perfection, and if all executions were carried out in a fair, timely, and humane method, there may be reason to accept such a society. Still many of us would be unnerved by such barbarity, hence no perfection at all.
Humanity, so far, has never reached that degree of sophisticated fairness. It is doubtful, that politically, and in rule of law nations, they ever could. What would more likely be created, and as we see today, is a constant and never-ending battle for the majority voice to slightly edge over the minority voice. This happens in each and every election cycle.
People wonder why our laws and leaders are so ineffective, and the answer is always the same, because people do not agree upon big issues. Nor should we, until we mature.
It takes the slow and inexorable march of time for people to accept civility toward other living beings. It took thousands of years, for example, for an overwhelming majority to accept that slavery may possibly be a bad idea.
It has taken a few hundred years more for the idea that women are equal to men to be accepted by an overwhelming majority. Even now, the reasoning behind why women should be allowed to wear bikinis rather than bee suit burkas, is often not that they are worth as much as men, but that women, generally, look better in bikinis!
Human beings and civilization are slow, and we are not yet at the point where we have given up outdated ideas such as “an eye for an eye, and a tooth for a tooth.” In the same texts that preach this very idea, by the way, it is quite thoroughly explained, that if you use, or abuse another’s slave, (their property) you owe them YOUR property, your slave.
It’s been almost a century since the great and sage Gandhi so rightly observed, “an eye for an eye makes the whole world blind”.