Learn the ins and outs of the polygraph and hypnosis in the world of crime. Is it in our nature to lie or do we really want to be honest? And how do we differentiate between the two? L. D. “Len” Zingg is a former army paratrooper and retired police lieutenant who served more than 27 years with the Phoenix police department. He has conducted over 10,000 polygraph examinations for the police department as well as hypnosis for victims and witnesses to enhance their recall of events. Len also owned and operated a private polygraph and hypnosis business. After retiring from the police department in 1990, he spent more than three years as Director of Operations for an organization charged with revitalization of Downtown Phoenix. He has authored four novels, a poem book and two children’s books. He and his wife, Lois Ann, presently reside in a retirement community in North Phoenix.