The Khmer Rouge regime took power on 17 April 1975 and was overthrown on 7 January 1979. Perhaps up to three million people perished during this period of 3 years, 8 months and 20 days. The end of Khmer Rouge period was followed by a civil war. That war finally ended in 1998, when the Khmer Rouge political and military structures were dismantled.
In 1997 the government requested the United Nations (UN) to assist in establishing a trial to prosecute the senior leaders of the Khmer Rouge.
In 2001 the Cambodian National Assembly passed a law to create a court to try serious crimes committed during the Khmer Rouge regime 1975-1979. This court is called the Extraordinary Chambers in the Courts of Cambodia for the Prosecution of Crimes Committed during the Period of Democratic Kampuchea (Extraordinary Chambers or ECCC).
The government of Cambodia insisted that, for the sake of the Cambodian people, the trial must be held in Cambodia using Cambodian staff and judges together with foreign personnel. Cambodia invited international participation due to the weakness of the Cambodian legal system and the international nature of the crimes, and to help in meeting international standards of justice. An agreement with the UN was ultimately reached in June 2003 detailing how the international community will assist and participate in the Extraordinary Chambers.
An international judge announced his resignation from the U.N.-backed war crimes trials in Cambodia on Tuesday, the fourth to quit so far and another blow for the troubled tribunal probing the atrocities of the 1970s Khmer Rouge regime.
Mark Harmon, from the United States, said in a statement his reasons for stepping down after three years in Phnom Penh were "strictly personal" and "with considerable regret". He did not elaborate.
Several of Harmon's predecessors at the hybrid United Nations-Cambodian court have alleged political interference and a lack of cooperation by Cambodia's government, which contains remnants of the Khmer Rouge regime.
Prime Minister Hun Sen, a former Khmer Rouge soldier, has warned more trials could cause anarchy and a return to civil war. He has promised to thwart new indictments and once said he would be happy if the U.N. packed up and left.
The decade-old tribunal has so far delivered verdicts involving three high-profile leaders from the 1975-1979 "killing fields" era. Attempts to pursue more cases have been met by strong government resistance.
Cambodian police have refused to act on an arrest warrant Harmon has issued for Meas Muth, a former navy chief alleged to have sent detainees to a torture center where some 14,000 people died.
Court spokesman Lars Olsen said Harmon's resignation was unrelated to any development in cases he was working on. Harmon would continue his role until his replacement was sworn in.