The Khmer Rouge tribunal has indicted four senior surviving leaders of the 1970s government that devastated Cambodia.
The tribunal Thursday announced the indictments of Nuon Chea, the Khmer Rouge's chief ideologue, the former head of state Khieu Samphan, former foreign minister Ieng Sary, and his wife, the former social affairs minister, Ieng Thirith.
Their trial is expected to start in the first half of next year. The suspects deny the charges against them.
Investigating judge You Bunleng says the four face charges ranging from genocide to crimes against humanity to torture and religious persecution.
You Bunleng says the charges should be seen in the context of an attack on the nation's entire population.
He says a demographic survey produced during the investigation showed that between 1.7 million and 2.2 million people died under the Khmer Rouge - many from overwork and illness.
Around 800,000 of the deaths were violent.
From 1975 to 1979, the Khmer Rouge tried to remake Cambodian society and forced most people out of the towns to labor in the countryside.
You Bunleng says the genocide charges relate to the killings of the minority Cham Muslims, and the deaths of ethnic Vietnamese living in Cambodia.
His co-investigator, Marcel Lemonde, acknowledges the case is complicated.
Judge Lemonde says some people have compared the complexity of the case to the Nuremberg trials of senior Nazis at the end of the Second World War. It is a comparison he feels is fair.
More than 2,100 people have been admitted as civil parties, which means the court recognizes that they or their relatives suffered from the specific crimes the four have been charged with.
It took years to form the joint international-Cambodian tribunal, but in July it wrapped up its first case. The judges sentenced Kaing Guek Eav, known as Duch, to 30 years in prison for war crimes and crimes against humanity.
Duch admitted running the S-21 prison in Phnom Penh, where as many as 20,000 people are thought to have been tortured and condemned to death.
Court spokesman Lars Olsen says Thursday's indictments move the court beyond Duch's case.
"This is addressing the leadership - those who are believed to have orchestrated all the crimes in the country. So of course for the people of Cambodia this means that those who are believed to have set in place the whole system now will face charges in a court," said Olsen.
But the four defendants are all in their late 70s or 80s. Many Cambodians fear they will not all live to hear a verdict.