In 1902 the force was split into General, Escort, Mines and Railway Police, which was legalized by the Police [Amendment] Ordinance of 1904.
The Marine Police was formed in 1916 but disbanded in 1942 and replaced by Customs Excise and Preventive Service.
The Criminal Investigation Department [CID] was formed in 1921 with the finger print section fully operational in 1922.
In 1948, the Police Reserves Unit was formed to combat riotous mobs, following the 1948 riots in the country.
The wireless and Communications Unit was formed in 1950 with the formal opening of the Police Information Room in Accra by the then Governor of the Gold Coast, Sir Charles Noble Arden Clark, in June 1950.
By 1952, a large number of Africans were enlisted into the Police Force as junior officers. The women branch of the service was then established, to be responsible for Juvenile crimes and offences committed by women. In 1958, the first Ghanaian Police Commissioner, Mr. E. R. T. Madjitey was appointed to head the service.
The Ghana Police Service as it is now called has as its motto “Service with Integrity”.
The functions of the Ghana Police Service as stated in the Police Service Act, 1970 [Act 350] of Ghana are as follows;