A former teacher accused of carrying out the murderous policies of Cambodia's Khmer Rouge will finally face trial Monday, as prosecutors launch their first case against the hardcore communists who turned the country into a killing field three decades ago.

A U.N.-assisted genocide tribunal has charged Kaing Guek Eav, 66, with committing crimes against humanity and war crimes, as well as torture and homicide.

The tribunal is seeking to establish responsibility for the brutal 1975-79 misrule of the group, when an estimated 1.7 million Cambodians died of starvation, medical neglect, slave-like working conditions and execution.

"Cambodians have been waiting 30 years for the Khmer Rouge to be tried for the violence and suffering they inflicted upon the population," said Prof. Alex Hinton, director of Rutgers University's Center for the Study of Genocide and Human Rights. "That day has arrived."

Kaing Guek Eav, better known as Duch, ran the group's notorious torture center in Phnom Penh. He holds the distinction of being not only the first member of the Khmer Rouge to face trial for the regime's atrocities, but also the only one to express remorse for his role.

Duch commanded the main Khmer Rouge prison known as S-21, or Tuol Sleng, where as many as 16,000 men, women and children were brutally tortured before being sent to their deaths.

He disappeared after the group fell from power, living under two other names, returning to teaching and becoming a convert to Christianity before he was discovered by chance by a British journalist in the Cambodian countryside in 1999.

Since then he has been in detention awaiting trial. Only now, after years of political and procedural wrangling, is his case ready to be heard.

"He is obviously a little stressed ahead of this process," his French lawyer, Francois Roux, said Sunday. "But at the same time, after 10 years of prison, at last the day is coming where he can in public respond to the questions."

For prosecutor Robert Petit of Canada, "what matters is all the right evidence is put before the judges so they can establish the truth for all to see."

Technically, Duch's trial opened in February, when the judges ruled on procedural issues such as scheduling and witnesses.

But Monday's hearing marks the start of its substantive phase, including the first chance for Duch to publicly tell his story, as well as confronting the families of victims.

Duch methodically recorded the treatment of each prisoner in thousands of documents that were found in the compound after the fall of the Khmer Rouge in January 1979. One shows Duch's signature on a list of prisoners, with the words "Kill them all."

Tribunal spokeswoman Helen Jarvis acknowledged that recounting gruesome details may be traumatic for the families of the victims.

"It's going to be a painful process but it's a process that we believe will lead to ... a feeling that finally justice is achieved, and it will be worth experiencing this pain," she told The Associated Press.

According to Information Minister Khieu Kanharith, Cambodian state television and radio are to broadcast Monday's proceedings live, and 70 percent of Cambodia's 14.3 million people are expected to tune in. The verdict at the end of the trial also is to be broadcast live.

"I will take that day off from my job and stay at home to watch the trial with my wife," said 37-year-old Min Kar, who earns about $10 a day driving a "tuk-tuk" taxi. He said four of his uncles died under the Khmer Rouge.

Several controversies dog the tribunal's work. Human rights groups want the number of defendants increased beyond Duch and the four senior Khmer Rouge leaders being held for trial in the next year or so.

"The successful start of the Duch trial ... does nothing to address the fact that only five people may be held accountable for the crimes that led to the deaths of as many as 2 million people," said Brad Adams, Asia director of New York-based Human Rights Watch. "It's a ridiculous proposition that only five people should be held accountable."

Critics of the tribunal charge that Cambodia's government has sought to limit its scope because other suspects are now loyal to Prime Minister Hun Sen, and to arrest them could be politically awkward.

Amnesty International and other groups have also urged the United Nations and the Cambodian government to address allegations that Cambodian staff have been required to pay kickbacks to government officials for appointments.

The charges cast "serious doubts on the chambers' competence, independence and impartiality," said a statement from London-based Amnesty International.

"Any corruption allegations must be investigated promptly and thoroughly," said Brittis Edman, the group's Cambodia researcher. "A failure to do so risks undermining the credibility of the whole institution and what it is trying to accomplish."