On 24 January 1932, officers of the Plymouth City Force were called into action to help quell disorder at Dartmoor Prison in Princetown, Yelverton.
Officers of the Devon County Constabulary, including its Chief Constable Mr Lyndon Henry Morris, also made their way to the prison.
Morris tried to negotiate with the prisoners, but when this failed the thirty-one strong force entered the grounds and successfully calmed the rioters.
Plymouth was heavily bombed during the Second World War, and on 30 April 1940 the force suffered its first casualty when Police Sergeant Edward Gibbs was killed along with his brother Sydney, and nephew David, during a raid on the Royal Dockyard in Devonport.
William Clarence Johnson succeeded Mr Wilson, and remained in office until 1936 when he left to become Deputy Chief Constable of Birmingham City Police.
Only Charles Cross is open to the public, and Crownhill is the site of one of Devon & Cornwall Police’s two control rooms, the other being located at Middlemoor in Exeter.