Kang Kek Iew or Kaing Kek Iev, also romanized as Kaing Guek Eav (Khmer: កាំង ហ្គេកអ៊ាវ), nom de guerre Comrade Duch or Deuch (មិត្តឌុច); or Hang Pin, (17 November 1942 – 2 September 2020) was a Cambodian convicted war criminal and leader in the Khmer Rouge movement, which ruled Democratic Kampuchea from 1975 to 1979. As the head of the government's internal security branch (Santebal), he oversaw the Tuol Sleng (S-21) prison camp where thousands were held for interrogation and torture, after which the vast majority of these prisoners were eventually executed.