Description:A former Cambodian prison chief known as Duch takes the stand at the U.N.-backed war crimes tribunal in Phnom Penh. The court is currently hearing a case against the three most senior surviving Khmer Rouge members, accused of war crimes, genocide, and crimes against humanity. Pol Pot, architect of the "Killing Fields", died in 1998. Survivors hope the trial will help uncover truths and bring justice for their suffering under the Khmer Rouge.(1:46)