The 101 responding agencies provide police service to almost 43 million citizens. The survey data, census data for 1980, and the Uniform Crime Reports for 1986 provided information to address six research questions. Results showed that the systems range from open systems emphasizing civilian involvement and citizen awareness to closed systems in which investigating units operate entirely within police agencies and give little or no information to the public. Community groups, civil rights organizations, and the media have favored open systems, while the police and conservative politicians have favored internal review. However, neither the frequency nor the seriousness of complaints are associated with any of the features of the complaints systems considered. Almost 30 percent of the agencies in the survey had made substantial changes in their citizen complaint procedures in the last 5 years; more than half had made changes in the last 10 years. The findings were used to develop a functional typology based on eight aspects of policies and procedures used. Discussion of methodological limitations, recommendations for future research, and appended figure.