As bloodthirsty dictator Pol Pot's trusted executioner, Kaing Guek Eav was responsible for the deaths of at least 14,000 people.
The Cambodian commander oversaw the infamous Tuol Sleng prison, where defenceless victims were tortured by the genocidal Khmer Rouge regime.
After being made to give "confessions", prisoners were executed in the notorious Killing Fields outside capital Phnom Phen. Their children were also murdered to prevent them seeking revenge, the executioner, known as Comrade Duch, later admitted.
But when the brutal government fell in 1979, Duch was able to escape the city. For 20 years he evaded justice, masquerading as a teacher, aid worker and born-again Christian - until he was exposed by photographer Nic Dunlop.
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