In 2003 he appeared in the Rithy Panh documentary S-21: The Khmer Rouge Killing Machine along with Cambodian artist Vann Nath where they were reunited and revisited the former prison, now known as the Tuol Sleng Genocide Museum in Phnom Penh. They met their former captors – guards, interrogators, a doctor and a photographer – many of whom were barely teenagers during the Khmer Rouge era from 1975 to 1979. Their appearances are in stark contrast to the two former prisoners, who were older during imprisonment and by the time of filming were both elderly men. Vann Nath, who was made to paint portraits of prisoners, had a full head of white hair. The guards and interrogators gave a tour of the museum, re-enacting their treatment of the prisoners and daily regimens. They looked over the prison's detailed records, including photographs, to refresh their memories.
