Why is a former head of state-sanctioned executions now an opponent of the death penalty? A host of countries around the world still impose the ultimate punishment on the most serious criminals - death. But what is it like to be in command of the machinery of state-sanctioned execution? In a rare insight, Stephen Sackur speaks to Allen Ault, who spent years running the corrections system in the southern US state of Georgia. He organised the killing of criminals until he could stand it no more. What changed?(Photo: Allen Ault - Former Commissioner of Corrections, Georgia, USA, on BBC Hardtalk)