After the Khmer Rouge victory in April 1975, Duch and his men set up prisons throughout the capital, including the infamous Tuol Sleng prison. Duch's request for a transfer in May 1975 to the Industrial Sector of government was denied. The Tuol Sleng prison camp was initially headed by In Lon (aka Comrade Nath) with Duch acting as deputy. Subsequently, In Lon was transferred and Duch was promoted to Director. By May 1976, all the prisons in Phnom Penh were consolidated and relocated to Tuol Sleng.