Now that I'm older, I worry about the possibility that banning the death penalty is an implicit acceptance of the policy of locking people away for life. According to the article 4% of people who are sentenced to the death penalty on death row are innocent. He doesn't offer statistics for the number who actually receive the punishment however given that not all people on death row are executed, and the significant resources devoted to the appeal process, the percentage of innocents who are executed must be lower than the 4% who are sentenced.
I must ask how many innocent people are sentenced to life in prison. I can't imagine anything worse than an innocent person sentenced to life in prison -- and eventually dying in prison.
If we are to make decisions about punishment taking into account the possibility of an incorrect sentence, I believe we need to be more realistic with regard to the hierarchy of punishments that we are inflicting. A sentence of Life in Prison carried to term is a worse punishment than Execution.