Criminal Investigation Department

The Criminal Investigation Department (CID) is a branch of British police organizations responsible for criminal investigations. It was established by the London Metropolitan Police in 1842 as a detective branch and later reorganized as the CID in 1878 following a corruption scandal. The CID initially consisted of plainclothes detectives who gathered information on criminal activities.12

The development of detective units in police forces, including the CID, arose from the need to investigate crimes that continued to occur despite the primary focus on crime prevention. Early investigators often brought corruption issues with them, leading to scandals and reorganizations in various cities, including London. By the late 19th century, the CID was a recognized part of Scotland Yard's operations, dealing with various aspects of criminal investigation.12