Death penalty is a strictest method of punishment. It was established at the beginning of the civilization. In ancient Greece and Roma the capital punishment was invoked for the different offenses. Socrates and Jesus were the most famous examples of people who had been sentenced to the capital crime in the history. Also Hammurabi's Code, which was the first code of laws, states that for the assassination the capital punishment is foreseen. In Anglo-American law the death penalty has been a form of the strictest punishment used in certain cases.
In my opinion the death penalty should be reserved for the worst crimes such as murders, espionage or some sexual crimes. If somebody kills another man, the one should be sentenced to the capital punishment. It would be fair. I hope that in this way some criminals would be afraid of committing the worst crimes and the crime rate would be getting lower.