By LUKE HUNT and SOPHENG CHEANG
Associated Press Writers

PHNOM PENH, Cambodia (AP) - Prosecutors in the genocide trial of a former Khmer Rouge prison chief demanded a lengthy jail term Tuesday, calling him the personification of ruthless efficiency in the killing of thousands of Cambodian prisoners.

Kaing Guek Eav commanded the notorious S-21 prison, where those accused of disloyalty to the xenophobic communist regime were held. He oversaw the torture and execution of about 16,000 men, women and children during the Khmer Rouge's 1975-79 rule.

If the U.N.-assisted tribunal finds him guilty, the former schoolteacher faces a maximum penalty of life in prison. Cambodia has no death penalty.

Prosecutors did not specify Tuesday how much time Kaing Guek Eav, also known as Duch (pronounced DOIK), should serve.

"The crimes of which he will stand convicted are of such an extreme seriousness and were committed against so many people that it is inconceivable that anything other than a lengthy sentence of imprisonment should be imposed upon him," prosecutor Chea Leang told the court.

"He was the personification of ruthless efficiency," she said. "He was totally indifferent to the suffering of the victims. He was the perfect candidate to run S-21."

Survivors of the S-21 have described how they were routinely beaten, received electric shocks, had their toenails torn out, and were waterboarded. Surgeries were performed on detainees without anesthetics.

"The cruelty towards the prisoners knew no limits," Chea Leang said.

Duch showed no emotion during the proceedings, which were observed by hundreds of schoolchildren and Buddhist monks and nuns in orange and white robes.

In his testimony, Duch has accepted responsibility for his role in overseeing the prison and asked for forgiveness from victims' families. He also told the court he was ready to accept heavy punishment for his actions. He has denied personally killing or torturing the S-21 prisoners, and said he felt compelled by fear for his own life to follow the orders of senior Khmer Rouge leaders.

As much as one-sixth of Cambodia's population perished from execution, overwork, disease and malnutrition as a result of the Khmer Rouge's radical policies - including the mass evacuation of towns and cities, and the ruthless persecution of alleged rivals.

Closing arguments began Monday with some of the handful of S-21 survivors and family members of the dead looking on. One of the lawyers for the victims charged that Duch pursued his role with zeal and had no empathy for his victims despite his expressions of remorse.

"He was not only proud of his job and convinced of the party line to identify and eradicate the enemy without any sense of guilt," lawyer Kong Pisey said. "Moreover, he enjoyed the power as a power-hungry man who performed more than 100 percent without any empathy for his victims."

As he watched the proceedings, Duch showed no emotion. He is expected to give his final statement as early as Wednesday. He is charged with crimes against humanity, war crimes, murder and torture.

The closing arguments will conclude Friday, while a verdict and sentence are expected early next year.

Duch is the only accused Khmer Rouge leader to acknowledge responsibility for his actions. Four other senior Khmer Rouge leaders are in custody awaiting trial.

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