Son Sen
A security apparatus called Santebal was part of the Khmer Rouge organizational structure well before 17 April 1975, when the Khmer Rouge took control over Cambodia. Son Sen, later the Deputy Prime Minister for Defense of Democratic Kampuchea, was in charge of the Santebal, and in that capacity he appointed Comrade Duch to run its security apparatus. When the Khmer Rouge took power in 1975, Duch moved his headquarters to Phnom Penh and reported directly to Son Sen. At that time, a small chapel in the capital was used to incarcerate the regime's prisoners, who totaled fewer than two hundred. In May 1976, Duch moved his headquarters to its final location, a former high school known as Tuol Sleng, which could hold up to 1,500 prisoners.