[1] Born in Glasgow, McNee worked as an office boy at the Clydesdale Bank before joining the Royal Navy as a rating in 1943.
He rose up the ranks to Inspector and served in the Flying Squad and Special Branch, until attending a senior command course at the Police Staff College, Bramshill, after which he was appointed Assistant Chief Constable of Dunbartonshire County Constabulary.
Determined to improve the working conditions of London's beat bobbies, McNee implemented several reforms to the Metropolitan Police, some of which would be further refined by his successors.
McNee considered that it was unfair for the subsequent Scarman Inquiry into the riot to concentrate on policing and not extend in depth to the wider social, political and economic context.
[4] He had earlier expressed his opinion that black people were disproportionately targeted by the sus law because there were indications that they were "over-represented in offences of robbery and other violent theft".
Chief Constable Leonard Burt told his investigation team not to pass any evidence it obtained against Metropolitan Police officers to the Met Commissioner, Sir David McNee.
Shortly before his retirement in February 1980, the Chief Constable of Dorset Constabulary, Arthur Hambleton, the superior of Burt, made allegations that Countryman had been willfully obstructed by Commissioner McNee and the Director of Public Prosecutions (DPP), Sir Tony Hetherington.
Retaining a strong Christian faith throughout his life, he was a member of the Church of Scotland and was on close terms with the minister of Saint George's Tron, the Rev Tom Allan,[3] a leading figure in the Scottish evangelical movement of the mid-20th century.