@ossobuco,
While on the face of it, it might seem offensive that the state takes a life, but in the big picture, the state takes countless lives. Every person who dies homeless and hungry for instance is a life that the state has effectively chosen to end, not by action but by inaction, in not providing mental health, shelter and food for those in desperate situations. Millions of troops have been called up over the years, and sent into harm's way, or even into a certain death. In these and other examples, we have people who have committed no crimes yet will die due to government decisions; is a convicted murderer's life somehow more valuable?
While nobody benefits from arbitrary and improperly administered justice, and nobody should endorse the death penalty being used to promote racism, that fear mustn't prevent its use any more than rocks should be banned from the earth simply because someone "might" use one improperly in throwing it through a window. Lives WILL be taken by the government in all cases; putting a person in prison for life is taking their life, just slower. The single important issue is that justice is administered with great care and accuracy.
The two cases that sum up for me this view are:
1) Charles Manson. Convicted in 1971 in the Tate "Helter Skelter" murders of 7 people, has been in prison since. Among the insanities of his imprisonment are his 12 appearances before the parole board, at which times injured parties/family members have repeatedly had to testify and relive the horror. His danger to the public has been very real even while imprisoned; he influenced Squeaky Fromme to attempt to assassinate President Gerald Ford in 1975, which she surely would have succeeded at had she been more competent.
2) Timothy McVeigh. Convicted in 1997 of the Oklahoma City Murrah building bombing that killed 168 people; executed in 2001.
Both crimes were horrific, neither man's guilt has ever been in question and both admitted to their crimes in addition to extensive forensic confirmation. McVeigh's chapter is over however. There are no parole hearings, no need to dredge up every detail every few years. There is no danger of him starting a new movement and recruiting actors into further mayhem, as Manson has done at every opportunity. No voices of protest have been raised saying McVeigh was wrongly convicted or executed.
Explain to me please how American society would be better with him alive.