ALTHOUGH LIE DETECTORS ARE ACCEPTED AND USED WIDELY BY INDUSTRY, ADMISSABILITY OF THE POLYGRAPHER'S ANALYSIS IN THE COURTS REMAINS A QUESTION FOR DEBATE. THE PRINCIPLES OF MODERN POLYGRAPHY ARE DISCUSSED IN RELATION TO LAW, PHYSIOLOGY, PSYCHOLOGY. ARGUMENTS IN SUPPORT OF THE ADMISSABILITY OF EVIDENCE BASED ON POLYGRAPH EXAMINATIONS IN CRIMINAL AND CIVIL TRIALS INCORPORATE SELECTED JUDICIAL DECISIONS AND PRESENT STATISTICS ON THE RELIABILITY OF THE EXAMINER'S INTERPRETATION OF THE TEST RESULTS. A HYPOTHETICAL CASE DETAILS THE CRITERIA REQUIRED FOR QUALIFYING THE POLYGRAPHER AS AN EXPERT IN COURT. THE SECOND HALF OF THE BOOK DISCUSSES PHYSIOLOGICAL PHENOMENA WHICH THE EQUIPMENT RECORDS. INDIVIDUAL CHAPTERS EXAMINE AUTONOMIC CARDIOVASCULAR TRACINGS, AUTONOMIC PNEUMOGRAPH TRACINGS, AND GALVANIC SKIN RESPONSE TRACINGS. THE DOCUMENT IS ILLUSTRATED WITH POLYGRAPH CHARTS AND ANATOMICAL DRAWINGS AND INCLUDES A PORTION OF A POLYGRAPH TESTING DATA SHEET. THIS BOOK, WRITTEN BY A MEMBER AND AN AFFILIATE MEMBER OF THE AMERICAN POLYGRAPH ASSOCIATION, IS INTENDED FOR JUDGES, DEFENSE ATTORNEYS, PROSECUTORS, AND MEMBERS OF THE SCIENTIFIC COMMUNITY. (AUTHOR ABSTRACT MODIFIED)