Fairness and effectiveness in policing : the evidence - National Research Council (U.S.). Committee to Review Research on Police Policy and Practices; Skogan, Wesley G.; Frydl, Kathleen; National Research Council (U.S.). Committee on Law and Justice; National Research Council (U.S.). Division of Behavioral and Social Sciences and Education; National Research Council of the National Academies (National Academies Press, 2004)