A police officer's belief system consists of beliefs, attitudes, values, and other subjective outlooks. The four typologies of police officers developed by White, Brown, Muir, and Broderick, respectively, can be synthesized into five types of police officers: the professional, the tough cop, the clean-beat crime fighter, the problemsolver, and the avoider. Other factors related to police attitudes include human nature, role orientations, legal restrictions, and clientele. Some police officers focus on processes; others on outcomes. Their attitudes also vary regarding selective enforcement, organizational context, job satisfaction, supervision, their peers, promotions, and coercion. Studies of police officers' outlooks could benefit from the development of valid and reliable measurement instruments. Tables, notes, and 58 references