Kang Kek Iew or Kaing Kek Iev, also romanized as Kaing Guek Eav (Khmer: កាំង ហ្គេកអ៊ាវ), nom de guerre Comrade Duch (មិត្តឌុច); or Hang Pin, (born 17 November 1942) was a leader in the Khmer Rouge during its rule of Democratic Kampuchea from 1975 to 1979. He is best known for heading the Khmer Rouge special branch and running the infamous Tuol Sleng (S-21) prison camp in Phnom Penh. He is the first Khmer Rouge leader being tried by the Extraordinary Chambers in the Courts of Cambodia for the crimes of the regime.
Kang Kek Iew was born in Choyaot village, Kampong Chen subdistrict, Kampong Thom Province, and is of Chinese-Khmer ancestry. A star pupil in his school, he passed his Brevet d'Etudes Secondaire de Première in 1961 at the age of fifteen. He finished the first half of his Baccalaureate in 1962 at the Lycée Suravarman II in the town of Siem Reap. The same year he was offered a place in the prestigious Lycée Sisowath in Phnom Penh where he completed his Baccalaureate in mathematics, scoring second in the entire country.
In 1964, Kek Iew began studying for his teaching certificate in Mathematics, a subject he loved, at the Institut de Pédagogie. The Institute was a cradle of activism under the directorship of Son Sen who was later to emerge as the Defence Minister of the Khmer Rouge and Duch's immediate superior.