This research studied the psychological aspects of citizens' assistance to law enforcement agencies on a confidential basis. The comprehensive observance of the psychological norms of cooperation is determined by the professional ethics of police officers, the necessity of nondisclosure of investigation secrets by citizens, and the security of the latter without compromising their constitutional freedoms. The research developed means of optimizing police-citizen cooperation, analyzed comprehensively the problems related to the psychological specificity of citizen involvement in confidential cooperation with special investigative agencies, the moral and legal aspects related to the operational methods in the activity of law enforcement agencies, and the psychological and pedagogical training of operational subdivision employees that work with persons who assist in preventing, stopping, solving, and investigating crimes on the confidential basis. By developing the communication and psychological competence of police officers, it is possible to provide for effective investigation that results in public security.