Abstract
EARLY ATTEMPTS TO DETECT DECEPTION THROUGH PHYSIOLOGICAL CHANGES MEASURED BLOOD PRESSURE AND BREATHING CHANGES; THE FIRST POLYGRAPH, RECORDING BLOOD PRESSURE, PULSE, AND RESPIRATION, WAS DEVELOPED IN 1921. POLYGRAPH THEORY ASSUMES THAT LYING INVOLVES PHYSIOLOGICAL CHANGES DUE TO A FEAR OF DETECTION. THE POLYGRAPH EXAMINATION CONSISTS OF THREE PHASES: PRETEST INTERVIEW, TESTING, AND A POST-TEST, WHICH MAY BE AN INTERROGATION IF THE TEST RESULTS SO WARRANT. POLYGRAPH EXAMINERS SHOULD FAMILIARIZE THEMSELVES AS MUCH AS POSSIBLE WITH A CASE BEFORE ADMINISTERING THE POLYGRAPH TEST. DURING THE PRETEST INTERVIEW, THE EXAMINER ADVISES THE TESTEE OF HIS CONSTITUTIONAL RIGHTS AND THE QUESTIONS HE WILL BE TESTED ON. THE TESTING PHASE INVOLVES GIVING THE TESTEE QUESTIONS PROVIDING A VARIETY OF STIMULI. QUESTIONS, ANSWERED BY YES AND NO, INCLUDE CONTROL QUESTIONS; TRUTHFULNESS OR DECEPTION IS DECIDED BASED ON A COMPARISON OF RESPONSES TO CONTROL AND TEST QUESTIONS. IF IT IS DECIDED THAT THE TESTEE IS LYING, FURTHER INTERROGATION IS PERFORMED. ALTHOUGH IT IS DIFFICULT TO RESEARCH THE VALIDITY OF POLYGRAPH TESTS, SOME STUDIES INDICATE THEIR FINDINGS ARE 90 TO 99 PERCENT ACCURATE. IN FEDERAL DISTRICT COURTS, POLYGRAPH EVIDENCE IS ADMISSIBLE AT THE COURT'S DISCRETION, ALTHOUGH CONFESSIONS RESULTING FROM POLYGRAPH EXAMINATIONS ARE ALMOST UNIVERSALLY ACCEPTED. INFORMATION IS ALSO GIVEN ON THE USE OF POLYGRAPH TESTS BY STATE AND LOCAL COURTS. FOOTNOTES ARE INCLUDED.
