The polygraph can be used to identify guilty parties and eliminate innocent persons when multiple suspects are being considered. It can also be employed to obtain confessions, which coupled with properly seized crime scene evidence ensure convictions free of plea bargaining. Moreover, statements made during any conversation in a polygraph test are admissible to impeach a defendant's testimony. When arson investigators suspect that persons previously interviewed may be withholding critical evidence, polygraph testing can provide the basis for a subpoena. Polygraph evidence is admissible in approximately 36 States as long as intelligent Miranda warnings are recorded and the defendant signs a written polygraph testing waiver. Judges, however, have the discretion as to admittance of the examiner's testimony as an expert. The paper provides an example of a question series performed prior to detailed polygraph testing of an arson suspect and interprets the possible answers. Factors limiting the polygraph's efficiency are obesity affecting health, medication, severe alcoholism, damage to the central nervous system, mental or nervous disorder, pregnancy, IQ below 70, and a subject being 13 years old or younger. Two references are supplied.