The author collected information on the performance of a sample of individual police forces in the five countries over the past 20 years. In addition, within each police force, the author obtained information about the activities of a cross-section of police stations. He also observed police operations in the field and interviewed police managers and supervisors at all levels. Objectives were to assess police effectiveness in crime prevention and to identify what police forces should do to deter crime. Procedures followed by police forces in the five countries to prevent crime are examined, with emphasis on whether police forces have enough resources and how decisions about resource allocations are made. The organizational structure and culture of the police forces and their impact on the ability of police officers to respond creatively to new challenges are examined. Organizational reforms that may affect the ability of police forces to protect society from crime are considered, as well as effective police crime prevention efforts that are compatible with democratic institutions and values. References, notes, and tables