The historical review of criminal investigation in Great Britain focuses on its development in the late 19th and 20th centuries as a set of routine practices as the key component of crime control associated with the growth of centralized bureaucracies and the national-state. Common myths about the nature of criminal investigation are identified and explored, and some theoretical approaches that involve an alternative perspective are considered. After the historical review, the three main types of detective units that conducted criminal investigations in the 20th century are profiled. These are generalist criminal investigation department (CID) offices, specialist squads, and ad hoc major inquiry teams. The major risks and weaknesses associated with each type of unit are identified. This section notes that criticism of the CID unit was particularly strong and sustained in Great Britain during the 1970's and 1980's, when corruption and malpractice led to a "crisis in legitimacy" for criminal investigations under this type of unit. The third section of the chapter describes the variety of substantial reforms, both internal and external, that have been mounted since this period in order to restore public confidence and improve the efficiency, integrity, and accountability of investigative practice. These reforms have included attempts at more systematic identification of cases likely to yield results; encouragement of greater use of "proactive" methods of investigation; and mechanisms to improve the integrity of the production of evidence, particularly regarding police interviewing. The author argues that the future is likely to hold strong challenges to some of the core assumptions underlying traditional approaches to crime control, particularly the routine practice of investigating and processing individual cases as the primary means of crime control. There is an emerging trend toward using partnership networks, crime analysis, and strategic planning as means of preventing crime, rather than relying primarily on investigative responses to individual cases after crimes have occurred. In Great Britain, such change is reflected in the National Intelligence Model (NIM), which is a business model for the organization of police responses that relies on the collection of relevant information as a basis for identifying and analyzing crime-relevant data, and developing strategies for addressing current and future crime problems. 11 notes and 108 references