Communist soldier who became Chief of Staff of the Khmer Rouge forces in Cambodia in 1972, including the Santebal secret police. He was killed on order of Pol Pot during the factional split the occurred within their party in 1997.
He was a teacher who became Director of Studies at the National Teaching Institute at the University of Phnom Penh.
He was accused of being complicit in the 1978 murder of Malcolm Caldwell, the British academic.
He married Yun Yat, the Party's minister of education and information.
He and his family were killed on orders of Pol Pot.