One assumed COP premise is a "structural premise" that what police departments do is shaped by their organizational structures. A second premise is a "contextual premise" that police agencies as open systems are constrained and influenced by their environments; and a third premise is a "universality premise" that, because the essential tasks of policing are universal, a single model of COP will apply to all sizes and types of police agencies. These premises are largely implicit and untested. To help fill this gap, three research questions corresponding to the three premises were empirically addressed: How strongly are implementations of COP connected to the structural features of police organizations in which they occur? How strongly are organizational structures predicted by characteristics of the community environments in which they are located? Are the patterns shown in answering the other two questions universal? These questions were addressed by obtaining data on community context variables, organizational structure, and COP operations from a nationwide sample of police agencies. The basic data source was the 1999 Law Enforcement Management and Administrative Statistics (LEMAS) survey, which yielded data on police organizational characteristics and on the adoption of COP procedures. This survey was supplemented with additional organizational data from other sources, including the 1996 Directory of Law Enforcement Agencies, which provides a census of all 18,769 police agencies throughout the United States; data on community characteristics; and crime data. Multiple regression analysis of the data found that the adoption of COP was not related to organizational structure; police organizational features and COP practices were not predicted by community characteristics; and there were large differences across agencies of different sizes and locations. 3 figures, 8 tables, 76 references, and a codebook