Originally posted by the Voice of America. Voice of America content is produced by the Voice of America, a United States federal government-sponsored entity, and is in the public domain. Defense Calls For Acquittal of Khmer Rouge War Criminal Robert Carmichael | Phnom Penh March 28, 2011 Kaing Guek Eav, also known as Comrade Duch, center, who ran the notorious Toul Sleng, a top secret detention center for the worst "enemies" of the state, looks on during his appealing at the U.N.-backed war crimes tribunal in Phnom Penh, Cambodia, March 2 Photo: AP Kaing Guek Eav, also known as Comrade Duch, center, who ran the notorious Toul Sleng, a top secret detention center for the worst "enemies" of the state, looks on during his appealing at the U.N.-backed war crimes tribunal in Phnom Penh, Cambodia, March 28, 2011 Defense lawyers for Comrade Duch, the former head of the Khmer Rouge's notorious S-21 prison, have asked the UN-backed war crimes tribunal to repeal his 19-year prison sentence. Comrade Duch, the Khmer Rougeâs former chief jailer, appeared at the war crimes tribunal in Phnom Penh Monday seeking his acquittal. Last year, the United Nations-backed tribunal sentenced Duch to 19 years in prison after ruling he was responsible for the deaths of more than 12,000 detainees at S-21 prison, which he headed between 1976 and 1979. The prison was used by the Khmer Rouge as a place to detain and torture thousands of perceived enemies of the revolution, before executing them. But on Monday Duchâs lawyers told the court their client should be set free since he was not a senior member of the Khmer Rouge movement, and had merely been following orders. The defenseâs appeal centered on its argument that the court lacked the jurisdiction to try Duch. But the one-hour speech delivered by Duchâs lead lawyer was rambling and repetitive, and ultimately unconvincing. Anne Heindel, a legal advisor with the genocide research organization DC-Cam, was present at Mondayâs hearing. Heindel says she would not be surprised if Duch ends up getting a longer sentence on appeal, not least since the prosecution has a much stronger case. "Based on what the prosecution says, because theyâve laid out a number of very compelling arguments,â Heindel said. âAnd based on what weâve seen this morning Iâd be surprised if the defense actually has any arguments to counter them." The tribunal has a mandate to try senior surviving leaders and those considered most responsible for crimes committed under the Khmer Rouge movementâs rule of Cambodia. The prosecution says that means there are two categories of potential defendants - senior leaders and those most responsible. But the defense says there is just one category - senior leaders who are also most responsible. And since Duch was not a senior leader who devised policy, the court should not have tried him. Legal experts do not consider that to be a strong argument, but it is a sign of how weak Duchâs position is. Duch has admitted his role in the deaths of thousands of people. The judges did ask the prosecution to justify the conclusion that there were two categories. International prosecutor Andrew Cayley told the court that the United Nations and the government had agreed on that approach. "The U.N. Group of Experts prior to the agreement in 1999 stated very clearly there were two types of individuals who should be prosecuted - namely senior leaders with responsibility over the abuses, as well as those at lower levels who are directly implicated in the most serious atrocities," said Cayley. Cayley said legislation enacted by the Cambodian government subsequently confirmed the division of suspects into two categories. Additionally, the prosecution said, Duchâs defense lawyers did not challenge the courtâs jurisdiction until the close of the trial - which was far too late. Duchâs appeal is scheduled to conclude on Wednesday and represents his last chance for release. The court will deliver its verdict in June. .