John Orr first joined the police as a cadet in 1961 at Renfrew and Bute Constabulary . As Detective Chief Superintendent of Strathclyde Police , he was appointed Senior Investigating Officer of the Lockerbie disaster which occurred on 21 December 1988 . This was the biggest single murder investigation in the history of Scottish policing
Lockerbie disaster
Pan Am Flight 103
John Orr (police officer)