KOK Sros

Mr. Kok Sros was called as a witness to testify on the functioning of S-21.

Kok Sros joined the Khmer Rouge revolution as a combatant in late 1973. After 17 April 1975, he worked as a guard in Ta Khmau prison, also known as the psychiatric hospital. In late 1975, he was assigned to work at S-21, again as a guard. About a fortnight before the Vietnamese army arrived in Phnom Penh, Kok Sros was sent to work in rice fields south of S-24.

As a witness, Kok Sros identified Duch as the Chairman of S-21 and said that he was called "Ta Duch" or Grandfather Duch at that time.

He described the detention conditions at S-21, saying that no detainee was allowed to leave S-21 alive. He recalled the screams of prisoners during interrogations. He recounted how prisoners would ask him and other guards the reasons for their arrest and detention at S-21, stating, "I just told them I did not know anything. It was the Angkar who arrested them and sent them here and I was in charge of [Ö] patrolling the location". Kok Sros also described his work as a guard at S-21, recounting the arrests of two members of his group. He told the Trial Chamber that the suffering of S-21 staff was "tremendous": "Every one of us suffered and we had no choice, we could not escape, and we had to work. Only time would tell". In his unit, only two of the guards he knew survived.

A lawyer assisted Kok Sros in case an issue of self-incrimination arose.