Historically, death penalty stem from the principle of Lex talionis, which amounts to a life for a life practices in several ancient civilizations like Egyptian and Greek. Various religious texts like Islamic sharia and Biblical theology also allow for capital punishment in cases of gross crimes like murder, rape etc. However, the process of ascertaining and sentencing is a formidable one and often opts for such punishment as the last resort after eliminating any reasonable doubt regarding the offence.
The forms of capital punishment itself have varied across time and countries. It has ranged from stoning, hanging by a noose, injecting of poison, guillotine, gas chambers to electrocution. Executions have been carried out in public as a means of educational examples to closed door occurrences witnessed by only the close relatives.
Derived from its Latin roots, capital punishment refers to the highest of punishment i.e. death penalty. Today, more than 60 countries (in some capacity) of the World still practice capital punishment in cases of some specific crimes. The crimes range from high treason to rape, genocide to drug trafficking etc. There does not seem to be a unanimous underpinning as far as the law is concerned and the application of the laws is also distinct for distinct jurisprudence.
Even though international organizations like UN have demanded complete abrogation of such punishments, the various countries want to practice highest form of deterrence when it comes to specific criminal offences. Even in India, death penalty is awarded for rarest of the rare cases like the Nirbhaya gang rape and Mumbai terrorist attack.
Often the opponents of such punishment highlight the counterproductive message of them as the law encourages murder in response to a murder. If awarded for crimes other than murder, they appeal to the law of proportionality where the punishment far exceeds the severity of the crime. They also argue in favor of life imprisonment or rigorous imprisonment in place of the death penalty. It also suggests a possibility of restorative justice than retributive. In addition to above arguments, they also highlight the fact that the justice delivery system has never been efficient enough to eliminate all forms of miscarriage of justices and arbitrariness.
Often in various countries, the sentencing and execution are interspersed by long spells (like decades) and these are often commuted in light of such inordinate delays. Hence, death cannot truly be justified or justly established.