Throughout the history of public policing, police agencies and those who govern them have recognized that policing is a profession that has inherent risks for misconduct and corruption. Codes of ethics have accompanied policing throughout its history. Ethical violations that transgress established and proposed codes of ethics can be categorized as organizational/rule violations, money corruption, and abuse of authority. Although all ethical violations involve a violation of an organizational rule or established police standard, money corruption and abuse of authority are discussed separately in this chapter because they are serious breeches of established police standards, laws, and often constitutional guarantees. Sexual misconduct and the acceptance of gratuities are discussed, followed by overviews of various types of police abuse of authority, namely, use of excessive force and the violation of citizen's constitutional rights in the interest of obtaining a conviction. A review of mechanisms for controlling police unethical behavior focuses on self-control, peer-group control, supervisory control, early warning audit systems, administrative reaction, and external accountability. 74 references