The dictum "Vengeance is mine, I will repay, saith the Lord" from the Bible should be something everyone should keep in mind when the desire to punish a criminal by taking away his life surfaces. The Bible makes it clear, vengeance belongs to god.
But on a more prosaic level, the controversy over the proposed hanging of Balwant Singh Rajoana for the assassination of former Punjab chief minister Beant Singh has opened up the debate once again on the desirability and efficacy of the death penalty. In India we have seen political parties and the public baying for blood in the case of Ajmal Kasab and Afzal Guru. Mercifully, the judiciary has not so far been influenced by this mob mentality and has proceeded on the facts of the case even though it has accorded the death penalty in the case of the latter.
The State taking away a life gives legitimacy to those who think that they can proceed on a parallel track and mete out 'appropriate' justice as in the case of the dubious khap panchayats. Then there is the issue of never being completely certain of a person's guilt. One of the justifications for killing a convicted criminal is that this is for the protection of society. But an incarcerated convict actually poses no threat to society and the State should not exceed the punishment by taking away a life.
Another purpose of the criminal justice system is the reform and rehabilitation of a criminal. Death is final and obviously does not serve this purpose. Studies in the US have found that life imprisonment is a far greater retribution than death. The death penalty is erroneously thought of by many as some sort of restitution of pain to the victim or the victim's family. But, in effect, there can be no such restitution except the psychological satisfaction that someone has paid the ultimate price. The eye for an eye may be a pillar of Islamic jurisprudence, but it is categorically rejected in most democratic societies.
The impulse for revenge is, of course, a strong motivation but no ethical government can justify the judicially sanctioned murder of a citizen on that ground. Irrespective of the nature of the crime for which the death sentence is awarded, the State can't get away from the fact that it constitutionally sanctions the right to life.
The murder of a citizen then contravenes this fundamental right. The argument that death is awarded for the rarest of rare cases too does not hold much water. There cannot be different categories attributed to say a murder for which a person is sentenced to death.
Howsoever much we want to punish a criminal in kind, the act of wilfully killing a human being with legal sanction violates the dignity and majesty of the law. If the Rajoana case can not only reopen the debate but also lead to the eventual abolishing of the death penalty, it'd have served some purpose.
As the Bible says, "The Lord giveth and the Lord taketh away."