On 7 September 2009, the international Co-Prosecutor filed two Introductory Submissions, requesting the Co- Investigating Judges to initiate investigation of five additional suspected persons. These two submissions have been divided into what is known as Case files 003 and 004.
The Co-Investigating Judges notified the Co-Prosecutors pursuant to ECCC Internal Rule 66 (1) about the conclusion of investigation in Case 003 on 29 April 2011. The International Co-Investigating Judge has later re-opened the investigation in this case.
Two inidviduals were initially named as suspects in Case 003. In June 2015, the Co-Investigating Judges issued a decision concluding the criminal and civik actions against one suspect, Sou Met, was exteniguished by his death in 2014. A second suspect, Meas Muth, was charged in absentia by the international Co-Investigating Judge in March 2015. He was notified of additional charges when he appeared before the international Co-Investigating Judge in December 2015.
The investigation in Case 003 is focused on crimes allegedly committed between 17 April 1975 and 6 January 1979 on the following locations:
- S-21 Security Centre, Phnom Pen
- Stung Tauch execution site, Ponhea Krek District, Kampong Cham Province
- Kampong Chhnang Airport Construction Site, Krang Leav commune, Rolea P’ier district, Kampong Chhnang Province
- Division 801 Security Centre,Veun Sai District, Rattanakiri Province
- Stung Hav Rock Quarry worksite, Kampong Som Province
- Wat Enta Nhien Security Centre and execution site (also known as Wat Kroam), Kampong Som Province
- S-22 Security Centre, Mean Chey District, Phnom Penh
- Durian Plantation,Ream Village, Ream Commune, Prey Nub District, Preah Sihanouk Province
- Bet Trang worksite, Bet Trang Commune, Prey Nub District, Preah Sihanouk Province
Information on how to apply to become Civil Party in Case 003