In their final appeals to jurors, prosecutors in capital murder trials are fond of quoting Scripture to lend authority to their arguments. And there are many verses to choose from. In particular, the Old Testament seems to suggest killing as a response to a variety of crimes. The most popular quotation is from Deuteronomy (19:21): "Life for life, eye for eye, tooth for tooth, hand for hand, foot for foot." Moreover, the Old Testament recommends death for an assortment of crimes, including murder, contempt for parental authority, defiling sacred places or objects, kidnapping for ransom, sorcery, bestiality, worshiping false gods, profaning the Sabbath, adultery, incest, homosexuality, blasphemy, bearing false witness in court, harlotry, negligence that results in a death, and false prophesy.

Yet, despite the apparent biblical endorsement of executions, there is much even in the Old Testament to suggest that...