ABSTRACT
From the late Victorian period onwards, the CID had become a feature of urban, and above all metropolitan police forces, with a well established reputation for incompetence and for venality and corruption. The emphasis on prevention and distrust of undercover police work that was characteristic of most police authorities had kept detective departments small and lacking in technical training and expertise; some smaller forces managed without any detectives at all, while in no force in the 1930s was the proportion more than six per cent of the establishment.2 Meanwhile, scandals involving corrupt practices erupted with monotonous regularity as the pressure for results during various clean-up campaigns pushed detectives and plain clothes officers towards the use and acceptance of illegal methods and inducements.
