Law enforcement officers are dependent upon citizens to alert them to criminal violations of the law. When citizens do not willingly communicate information to the police or cannot be induced to do so, police officers themselves adopt fictitious identities of various types. This paper explores police undercover work, a form of covert law enforcement used to gather information about conduct external to the organization. Through interviews with supervisors and practitioners, the benefits and liabilities of the assignment for the officers and the organization are presented. The work enables the police to investigate citizens who are not suspected of criminal activity and therefore lends itself to abuse. The practice itself demands attention as the lack of operational guidelines, standardless selection of operatives, and loose supervision imperil the safety of officers and the rights of citizens.