This feeling inevitably provokes some to remind us that the death of the murderer in no way changes the outcome of their actions -- their victims are still dead. To put a murderer to death is an abuse of the power of the State, it serves no useful purpose, and the murderer can easily be condemned to a life incarcerated, with no hope of parole. Invariably, this leads to a brouhaha over the cost of incarceration, law, justice, morality, and government that leads to no clear winner or loser of the argument, and the same problem as before -- what to do?
We must ask ourselves, as humanity, what is in the best interests of us all? Is the desire for vengeance greater than the desire for justice? Are we to be ruled by the laws of rational humanity, or the laws of our still extant animal passions? What price do we pay, as individual people, as a society, as humanity, for putting a person to death, even if that person has committed the most flagrant and destructive acts?
Clearly, to kill a murderer is to eliminate a problem. It removes the potential for escape, for recidivism, and for perpetuation of the aura surrounding such a person (the potential for that person to become a perverted icon for "worship"). It is, literally, a dead end, and we can awake the next day knowing they will plague us no longer. And yet... at what point is their death really justified? Do we judge the severity by body count, or who was murdered, or the means of the murder, or the defendants justifications? What criteria do we define for execution, so as to be fair and just? The States have struggled with these questions for as long as there has been a United States, and in over two hundred years, there has been no good resolution. As noted above, Biblical times were also fraught with a conflict between "Thou shall not kill" and "eye for an eye." And we have not even broached the idea of the death of an innocent person, convicted of a murder they did not commit.
Depending on your predilections, you will lean one way or the other, and consensus is but a fleeting hope. Perhaps, though, we should look at the problem not as the specific instance of the crime, but as an adjunct to human society. Instead of making the focus so narrow, we should, instead, broaden the scope.
It comes down to the principles we wish to base our human society on. Law, and justice, are but a small part of the human experience, and while our society is constructed around the idea that law exists to protect us and allow us the freedom to be who we are, free of the interference of others, we know we give up some of that freedom in order to follow the law. Moral conundrums are aplenty, as it is possible to argue that in certain instances, perhaps the ends justify the means, and the man who steals medicine for his sick wife, or the wife who kills her abusive husband, are obeying some "higher order" of morality that supersedes ideas human law and justice. The case can be made that society is stable, only where law cannot be absolute, and where the letter of the law may be bent to fit the circumstance.
When humanity began to assemble more and more complicated arrangements, from tribes, to settlements, to towns and cities, up to nation states, law had to adapt to the plethora of instances and circumstances that were spawned by these increasingly larger groups. Law moved from the simple level of commandments, to pervasive codes that were important to standardize personal freedom and responsibility, commerce, trade, and relations between these entities. The complexity of law in modern times, makes the case for what constitutes justice that much more difficult to parse. A legal process that is fraught with technicality and is inured with outmoded social mores, combined with rapid changes in society and technology, leads to a no-man's land of loopholes, test cases, and overwrought precedent.
It is in this cloud of uncertainty, that we are asked to render judgment. We must, somehow, take all these things into consideration, and determine what course is best. In courtrooms every day, law and justice are thrashed about, burned in the crucible of human emotion, and recast and retooled. The product is not always pure, nor is it always empathetic, nor even just; the best that can be said, is that the attempt has been made and that is the best we can do today.
Where human life is concerned, however, that may not be good enough. Holding the life of another in our hands, we only have our experiences and beliefs and codes of conduct to guide us. The determination of whether a convicted criminal deserves to die, is a mountain more daunting than even Mt. Everest in Winter.
Maybe, then, it is best to declare, once and for all, that killing someone is wrong, even if it is the State doing it. We do ourselves a disservice with moral equivocation; just as it is said that one cannot teach a child to forgo violence by using corporal punishment on him/her, perhaps the child that is current human society cannot progress until it is taught that violence as a form of resolution is unacceptable. Only when we put aside animal instinct for human reason and deduction, can we say we have left the infancy of our species behind.