Sting operations have been part of the modern police response to crime for over 40 years. For the majority, sting operations contain four basic elements: (1) an opportunity or enticement to commit a crime, either created or exploited by police; (2) a targeted likely offender or group of offenders for a particular crime type; (3) an undercover or hidden police officer or surrogate, or some form of deception; and (4) a "gotcha" climax when the operation ends with arrests. Sting operations can be expensive, are demanding on personnel, and generally offer limited relief from recurring crime and disorder problems. This is not to say that they should never be used. They may be beneficial when used in concert with other police responses known to provide long-term solutions to the problems, such as a tool to collect information that will help in mounting other preventative operations. Clearly, sting operations do provide some attractive benefits to police departments, particularly by facilitating investigation, increasing arrests, and fostering a cooperative spirit between prosecutors and police, all of which result in favorable publicity. However, law enforcement agencies need to assess these benefits against the negative ethical and legal problems associated with sting operations, especially the finding that in some cases they increase crime, and in the long-term, with some exceptions, generally do not reduce it. This guide produced by the Office of Community Oriented Policing Services under the Response Guides Series is intended to help law enforcement agencies decide whether a sting operation would be right for the agency. Appendix, notes, and references