On 12 August 1966, a Metropolitan Police crew in an unmarked Triumph 2000 Q-car, registration plate GGW 87C and call sign "Foxtrot One One", was patrolling East Acton (although the incident was always reported by the media as occurring in Shepherd's Bush) in west London. Detective Sergeant Christopher Tippett Head, aged 30, and Temporary Detective Constable David S Bertram Wombwell, aged 25, were both members of the Criminal Investigation Department (CID) based at Shepherd's Bush police station in F Division. Their driver was Police Constable Geoffrey Roger Fox, aged 41, class 1 advanced driver, a beat constable who had served for many years in F Division (which covered the Metropolitan Borough of Hammersmith) and frequently acted as a Q-car driver due to his vast local knowledge. All three officers were in plain clothes.