CHOEUNG EK, Cambodia (Reuters) - The chief torturer under the Khmer Rouge "Killing Fields" regime wept and prayed on Tuesday as he led the judges who will try him for crimes against humanity around the mass graves for some of its victims. Duch, also known as Kaing Guek Eav, accompanied 80 judges, lawyers and other officials of a U.N.-backed tribunal to the 129 graves, uncovered after a Vietnamese invasion sent the Khmer Rouge back to the jungles in 1979. "I saw Duch kneel in front of the trees where Khmer Rouge soldiers smashed children to death," a policeman told reporters...