Complex sentence: He joined the police force in 1940 and the Police Surveillance Agency in 1948, and rose to become Assistant Chief of Police and head of counter-intelligence, reporting directly to the Director of the Police Surveillance Agency.
Split into simpler sentences: He joined the police force in 1940 and the Police Surveillance Agency in 1948. He eventually rose to become Assistant Chief of Police and head of counter-intelligence, reporting directly to the Director of the Police Surveillance Agency.