A professional who interrogates and screens individuals to detect deception or to verify truthfulness, using polygraph equipment and standard polygraph techniques. Responsibilities include:

• Attaches apparatus to individual to measure and record changes in respiration, blood pressure, and electrical resistance of skin as result of perspiration changes.
• Evaluates reactions to questions of a non-emotional nature.
• Interprets and diagnoses individual's emotional responses to key questions recorded on graph.
• Visits morgues, examines scene of crime, or contacts other sources, when assigned to criminal case, to gather information for use in interrogating suspects, witnesses, and other persons.
• Appears in court as witness on matters relating to polygraph examinations, according to formalized procedures.
• Prepares reports and keeps records on polygraph examinations.
• May instruct classes in polygraph interrogation techniques, methods, and uses.
• When analyzing voice stress charted on moving tape by needle of recording device for deception or truthfulness verification, may be designated Psychological Stress Evaluator.