This book wrote experienced criminal investigators. The book will be useful for polygraph examiners, criminal police investigators, researchers, students, prosecutors, lawyers and judges. In this book the authors wanted to show problems, arising from polygraph tests, as well as very broad possibilities. The authors are absolutely sure that part of the lie detection specialists may disagree with our stated ideas. For the readers, who want to know more about polygraph lie detection techniques, theoretical models of lie detection, the authors have provided a wide list of references.