William Douglas was a native of Ayrshire and joined the City of Glasgow Police on 16 September 1885 at the aged of 22. He was posted to the ‘A’ (Central) Division.
Afer 6 month street duty he was appointed as a turnkey at the Central Police Office and afterwards Telegraph Clerk. During this time, the telephone was introduced to Glasgow Police.
In 1888 he was promoted to Detective Officer in the Detective Department. Three years later, in 1891 he was promoted to Lieutenant. In 1897 he was promoted to Chief of the Detective Department and while there, introduced the Bertillion system of identification and carried it on until it was superseded by the fingerprint system.
In 1900 he was promoted to Superintendent in the Marine Division and in 1906 was transferred to the ‘B’ Western Division. In 1909, following the murder of Mrs Marion Gilchrist, he oversaw the investigation and gave evidence at the Trial of Oscar Slater.
He was awarded the King’s Police Medal for Distinguished Service in 1921 and a few months later took ill and died ‘in service’ on 18 December 1921 at the age of 58.