Following public criticism of the Metropolitan Police's handling of major crimes, the Criminal Investigation Department (CID) was formally established at Scotland Yard in London in 1878. The CID created a dedicated body of plainclothes detectives responsible for serious criminal investigations, with clearer procedures for evidence collection, witness interviewing, and case management. It represented the institutionalisation of detective work in Britain and became the template for criminal investigation departments across the British Empire.

The creation of the CID coincided with the explosion of Victorian detective fiction, and the two developments shaped each other. Wilkie Collins's The Moonstone (1868) and later Doyle's Holmes stories reflected and reinforced public interest in professional detection. The CID's real cases — particularly the Jack the Ripper investigation of 1888, which exposed the limits of Victorian evidence gathering — generated enormous literary and journalistic output, reshaping representations of police and crime in British culture.