The Michigan State Police established the first State police polygraph unit in the United States. The first examiner, Harold Mulbar, was trained by Leonarde Keeler in 1934. The unit was operational in early 1935. The polygraph was quickly recognized as a valuable investigative tool by both police and prosecutors. Due to increased demand for its services, the section has expanded over the years until now units are established at various State police facilities throughout the State. When the Forensic Polygraph examiners Act was enacted in 1972, the educational level of polygraph trainees was upgraded. Examiners have been trained at several different polygraph schools, producing a synthesis of the knowledge from the various schools within the unit. In its 50th year, the polygraph section conducted approximately 3,500 examinations. Over 90 percent of the cases were felonies. This study cites some of the notable cases the section has helped clear over the years. The overall performance of the section is also documented. 30 references.