Polygraph or Lie Detector

A polygraph machine is a law enforcement tool that purports to determine whether a subject is telling the truth or not. The polygraph, or lie detector, as it is commonly called, is attached to the subject and measures changes in blood pressure, galvanic skin response, and heart rate. The polygraph technician, usually a highly trained individual, then interprets the responses and makes a determination whether the subject is being truthful. The results of polygraph examinations are generally not admissible as evidence in court. The fact is, however, that law enforcement will be led to and away from possible suspects if they either fail or refuse to take a polygraph test. Computerized voice stress analysis is another fairly reliable means of determining truthfulness.