Author John F.X. Lyng was a member of the Jersey City, NJ Police Dept. from 1948 to 1976; from1961 to 1976 he served as the chief polygraphist in the city. He retired from the police in '76, whereupon he continued to conduct examinations, investigations and lecture on the topics he became most known for – primarily interrogation. He was licensed by the State of New York to teach polygraph procedures, interrogation, and investigation techniques. Mr. Lyng was an instructor at the National Training Center of Polygraph Science in New York City from '61 through '77. After his retirement, he conducted polygraph examinations on a private basis for district attorneys, public defenders, and lawyers in New York, New Jersey, Delaware, Connecticut, and Massachusetts. He lectured on polygraph procedures, investigation, and interrogation for more than 500 United States and Canadian law enforcement agencies.