Criminal Investigation Department
In the United Kingdom and many former British colonies, Criminal Investigation Department (CID) is the generic name for the branch of a police force to which most plainclothes detectives belong. A force's CID is distinct from its Special Branch (though officers of both are entitled to the rank prefix "Detective").
The Metropolitan Police set up a detective branch with eight plainclothes detectives in 1842, thirteen years after it was established in 1829. Detective units were established in the City of London Police and in other major cities and towns from the mid-nineteenth century onwards.
On 8 April 1878 C. E. Howard Vincent re-formed the Metropolitan Police Detective Branch into the CID. Originally, Vincent's CID was under the direct command of the Home Secretary, but since 1888 it has reported to the Commissioner of Police.
British colonial police forces all over the world adopted the terminology developed in the UK in the 19th and early 20th centuries, and later the police forces of those countries often retained it after independence. English-language media often use "CID" as a translation to refer to comparable organisations in other countries.
