Assuming those elements are satisfied, capital punishment is warranted in certain situations.
The prospect of conviction in error is one of the strongest positions against capital punishment, precisely because the concept of valuing the preservation of the freedom of the innocent from wrongful conviction over the value of ensuring punishment for the guilty is fundamental to American justice. By extension, one could argue convincingly that protection against wrongful execution is even more important than wrongful criminal conviction in general. However, it is possible to establish more stringent standards of proof, judicial review, and myriad other conceivable procedural safeguards short of abolishing capital punishment altogether. Therefore, that approach would seem logically preferable.
Capital punishment is the only practical alternative to conviction for crimes so heinous that they require lifetime incarceration, as much to protect innocent members of society as to provide a means of punishment or retribution. In that sense, it is difficult to understand the suggestion that individuals too dangerous to live among the rest of civilized society have any moral right to lifetime sustenance at the expense of the very members of society who must be protected from their voluntary conduct.
In many cases, the outrageousness and cruelty of criminal acts justifies protecting innocent members of society from further harm in a manner more beneficial to society than a manner more beneficial to the criminal, and at society's expense. By
Capital punishment is morally justified in certain circumstances, in which case the remaining moral obligation of a civilized society is simply to ensure that the sentence is carried out quickly, efficiently, and without unnecessary suffering.
References
Dershowitz, Alan, M. (2002) Shouting Fire: Civil Liberties in a Turbulent Age. New York: Little Brown & Co.
Friedman, Laurence, M. (2005) a History of American Law. New York: Simon & Schuster.
Hall, Kermit, L. (1992) the Oxford Companion to the Supreme Court of the United States. New York: Oxford University Press.
Nowak, John, E., Rotunda, Ronald, D. (2004) Nowak and Rotunda Hornbook on Constitutional Law, 7th Edition (Hornbook Series). St. Paul, MN: West
Schmalleger, Frank. (1997) Criminal Justice Today: An Introductory Text for the 21st Century. New Jersey: Prentice Hall
Zalman, Marvin. (2008) Criminal Procedure: Constitution and Society, Fifth Edition. Princeton: Pearson.
