United States Supreme Court Justice William Brennan once argued against capital punishment, saying, "The calculated killing of a human being involves, by its very nature, an absolute denial of the executed person's humanity." Justice Brennan claimed the 8th Amendment bans "cruel and unusual punishment." Yet the 5th Amendment refers to "capital or otherwise infamous crime" and says no person "shall be deprived of life, liberty or property without due process of law."
As Justice William Brennan said in the case Gregg v. Georgia, "the death penalty, unnecessarily to promote the goal of deterrence or to further any legitimate notion of retribution, is an excessive penalty forbidden by the Eighth and Fourteenth Amendments."
"One area of law more than any other besmirches the constitutional vision of human dignity. . . . The barbaric death penalty violates our Constitution. Even the most vile murderer does not release the state from its obligation to respect dignity, for the state does not honor the victim by emulating his murderer. Capital punishment's fatal flaw is that it treats people as objects to be toyed with and discarded. . . . One day the Court will outlaw the death penalty. Permanently."