Son Sen
On 20 July 1962, Tou Samouth was murdered by the Cambodian government. At the WPK's second congress in February 1963, Pol Pot was chosen to succeed Tou Samouth as the party's general secretary. Tou's allies Nuon Chea and Keo Meas were removed from the Central Committee and replaced by Son Sen and Vorn Vet. From then on, Pol Pot and loyal allies from his Paris student days controlled the party center, edging out older veterans whom they considered excessively pro-Vietnamese.