 Like his brother Lon Nol, he was educated at the Lycée Chasseloup-Laubat in Saigon, and like the rest of his family became employed in the state security apparatus.He eventually became police commissioner of Memot in Kampong Cham Province.While Prince Norodom Sihanouk was on a trip abroad in Beijing, China, on March 18, 1970, Prince Sirik Matak assisted Lon Nol in organizing a vote of the National Assembly to depose Sihanouk as Head of State, giving himself emergency powers.