Proper justice insists upon a punishment that befits the crime committed. Though severe, the death penalty is, at times, an appropriate and proportionate punishment when the courts deem a crime sufficiently heinous.  Not only does the death penalty provide closure for those affected by the crime,  but it also demonstrates a state’s commitment to upholding a system of justice and, in doing so, deters potential criminals from future offenses. 
Capital punishment is symbolically significant, in that it exhibits a state’s commitment to the safety of its law-abiding citizens and reinforces a population’s sense of security, a sentiment crucial to a prosperous and functional society.  Further, execution prevents the offender from the possibility of re-offense.  Though death-penalty skeptics argue that re-offense is rare when a criminal faces life without parole,  one must consider two points: 1. the offender remains a threat to prison staff/fellow inmates if allowed to live, and 2., the offender, in certain instances, maintains influence over a non-incarcerated population compelled to do the offender’s bidding (e.g. in cases of despotic leaders who garner political influence).
One must maintain a consequentialist view, which argues that if the death of a few individuals nets an aggregate increase in well-being for a population, then the deaths within this system are morally justified.