Joining Lanarkshire Constabulary in 1931 and posted to Bellshill police station, Inch was promoted sergeant in 1936.
Undertaking further studies, Inch obtained an LLB and in 1938, at the age of 27, was promoted to inspector in charge of recruit training.
He qualified as an Air Raid Precautions (ARP) instructor and became the organiser of civil defence in Lanarkshire on the outbreak of World War II.
As Chief Constable of Edinburgh, Inch was a member of the organising committee for the Commonwealth Games held in the city in 1970.
[4][5] In 1975, Edinburgh City Police amalgamated with Berwick, Roxburgh, Selkirk and Lothian and Peebles Constabularies to form Lothian and Borders Police,[6] and Inch served as Chief Constable of the new force until his retirement in 1976.