The paper emphasizes the central role of statistical departments in providing information to policy divisions and administrative systems. At the operational level, police officers, prosecutors, court officials, probation and parole officials, and prison authorities need to know detailed information about crime, victims, suspects, and offenders. Policy administrators need to know how policies are working and how the social and technical environment is changing. In England and Wales, criminal justice is managed by the Home Office, the Crown Prosecution Service, and the Lord Chancellor's Department. The Research and Statistics Department is the primary source of data for policy analysts. Statistics influence policy analysis by measuring crime, police workloads, the work of prosecutors and magistrates, sentencing trends, and the work of probation and prison services. The use of statistics in certain specific areas is described, including the British Crime Survey, police-recorded crimes, the Homicide Index, databases of the Crown Prosecution Service and courts, offenders, probation, and prisons. The role of computers in maintaining statistical databases is addressed.