The Khmer Rouge tribunal this week is to hear from two key witnesses in the trial of former S-21 chief Kaing Guek Eav, according to the latest scheduling order released Thursday. After wrapping up the last of testimony from alleged survivors of the prison today, judges are expected to call on surviving former staff members at the prison, including former prison guard Him Huy and former deputy S-21 chief Mam Nai. A total of 34 key witnesses and civil parties have been listed in the latest schedule, which covers the period ending August 26. Historian David Chandler has also been scheduled to testify as an expert witness in the first week of August.