On a biting cold morning on November 28, 1972, a Frenchman was guillotined for a murder he did not commit, in a case that so traumatized his lawyer he would spend the rest of his life campaigning to end the death penalty. Roger Bontems, 36, was beheaded for being an accessory to the brutal murder of a nurse and a guard during a break-out attempt at a prison in eastern France. Seven minutes after he was decapitated in the courtyard of La Sante prison in Paris, his co-conspirator Claude Buffet -- a 39-year-old man convicted of a double murder that...