A polygraph can fine-tune the focus of an investigation, confirm witness and victim statements, and even produce a confession from a suspect if it is used properly. Properly incorporating the polygraph into a law enforcement setting depends on selecting the right person to become a polygraphist, sending that officer to an accredited polygraph school, conducting exams as intended by their creators, and using the polygraph as a tool to enhance an investigation rather than take the place of one. Officers selected to become polygraphists should have maturity, experience, compassion, and professionalism. They should also have two to four years of education beyond high school, preferably in psychology and criminal behavior. An officer should have broad experience in criminal cases, including investigative experience. Interrogation skills are also important. This article discusses the selection of a training academy, the correct application of exams, techniques and instrumentation, proven pretest methods, and conduct during the test. Follow-up training is also considered. 6 listings for further information