Pol Pot's Executioner: Welcome to Hell

On 28 February 2009 Kaing Guek Eav, alias Duch, appeared in the ECCC courtroom and made a two-hour speech where he asked for forgiveness for the appalling torture and execution of at least 13,000 prisoners at Tuol Sleng and probably more in the security camps of M-13 and M-99. Until this date, with the exception of a handful of judges, lawyers and a priest, he had not been seen or heard of for the last thirty years. How did a man, known to be kind and generous to fellow students, possibly transform himself into Comrade Duch, the Khmer Rouge's infamous executioner? This documentary revisits and searches for clues.

Part of the Justice Season on BBC4.