Mr. Prak Khan was called as a witness to testify on the functioning of S-21.
Mr. Prak Khan joined the Khmer Rouge in 1972. He worked in a farming unit before being transferred to Division 703. After participating in the capture of Phnom Penh, he was assigned to work in the S-24 rice fields. In late 1975 or early 1976, he was sent to S-21 to work as a guard outside the S-21 compound. In late 1976, Prak Khan was assigned to work as an interrogator in the so-called "chewing" group.