Two former Khmer Rouge leaders were tried in Case 002:
- Nuon Chea, former Chairman of the Democratic Kampuchea National Assembly and Deputy Secretary of the Communist Party of Kampuchea; and
- Khieu Samphan, former Head of State of Democratic Kampuchea.
Nuon Chea and Khieu Samphan were charged with crimes against humanity, grave breaches of the Geneva Conventions of 1949, and genocide against the Muslim Cham and the Vietnamese.
Two other co-accused, Ieng Sary and his wife Ieng Thirith, were also part Case 002.The proceedings against Ieng Sary were terminated on 14 March 2013, following his death the same day. Ieng Thirith, was indicted but later found unfit to stand trial due to her dementia and separated from the case in November 2011. Following a re-assessment by medical experts in August 2012, The Trial Chamber found that Ieng Thirith remained unfit to stand trial. The medical experts concluded that no further available medical treatment was likely to improve Ieng Thirith's fitness to stand trial. Ieng Thirith was released from provisional detention on 16 September 2012 and died in August 2015.
The first trial, Case 002/01, commenced on 21 November 2011, primarily focusing on alleged crimes against humanity related to the forced movement of the population from Phnom Penh and later from other regions (phases one and two), and the execution of Khmer Republic soldiers at Toul Po Chrey execution site immediately after the Khmer Rouge takeover in 1975.
Case 002/01 also considered the roles of the Accused in relation to regime policies relevant to all charges.
The hearing of evidence in case 002/01 ended on 23 July 2013 and the closing statements concluded on 31 October 2013. The trial judgment was pronounced on 7 August 2014.
Nuon Chea and Khieu Samphan were found guilty of crimes against humanity and sentenced to life imprisonment.
On 23 November 2016, the Supreme Court Chamber issued its appeals judgement reversing some of the convictions, upholding the rest and confirming the sentences of life imprisonment for crimes against humanity.
Case 002/02 refers to the second trial against Khieu Samphan and Nuon Chea where additional charges from the Closing Order in Case 002 will be heard. In a decision on 4 April 2014, the Trial Chamber decided that the following alleged crime sites and factual allegations would form the basis for Case 002/02:
- Genocide against the Cham and the Vietnamese (excluding crimes committed by the Revolutionary Army of Kampuchea on Vietnamese territory);
- Forced marriages and rape within the context of forced marriage (nationwide);
- Internal purges;
- S-21 Security Centre; Kraing Ta Chan Security Centre, Au Kanseng Security Centre and Phnom Kraol Security Centre;
- 1st January Dam Worksite; Kampong Chhnang Airfield Construction Site, Trapeang Thma Dam Worksite;
- Tram Kak Cooperatives;
- Treatment of Buddhists (limited to Tram Kak Cooperatives); and
- Targeting of former Khmer Republic officials (implementation limited to Tram Kak Cooperatives, 1st January Dam Worksite, S-21 Security Centre and Kraing Ta Chan Security Centre).
Evidentiary hearings in Case 002/02 commenced with opening statements on 17 October 2014 and concluded on 11 January 2017. During the trial, the Chamber heard the testimony of 185 individuals, including 114 witnesses, 63 Civil Parties and eight experts. The evidentiary base in Case 002/02 included more than 10,800 documents for analysis and consideration by the Trial Chamber.
On 16 November 2018 the Trial Chamber announced a summary of its findings and the disposition in Case 002/02. It notified the trial judgment in Khmer, English and French on 28 March 2019. The Chamber found Nuon Chea and Khieu Samphan guilty of crimes against humanity, grave breaches of the Geneva Conventions and genocide of the Vietnamese ethnic, national and racial group. The Chamber additionally convicted Nuon Chea of genocide of the Cham ethnic and religious group under the doctrine of superior responsibility. Both Nuon Chea and Khieu Samphan were sentenced to terms of life imprisonment. The Chamber took into consideration the life sentences imposed on Nuon Chea and Khieu Samphan in case 002/01 and merged the sentences in cases 002/01 and 002/02 into a single term of life imprisonment.