Leonarde Keeler

Leonarde Keeler was an American psychologist and inventor known for his work in developing the polygraph, or lie detector, in the early 20th century. Following the innovations of his mentor John Larson, Keeler significantly advanced polygraph technology and gained fame for his ability to exonerate numerous suspects through lie detection tests. His methods laid the groundwork for the use of polygraph testing in both legal and investigative contexts in the United States.