Leonarde Keeler

Leonarde Keeler (1903 to 1949) was an American inventor best known for co-inventing the polygraph. Born in North Berkeley, California, and nicknamed Nard after Leonardo da Vinci, he was a high school student and amateur magician who worked for the Berkeley Police Department under Chief August Vollmer and became captivated by John Augustus Larson's cardio-pneumo psychogram, a machine meant to detect deception. His first handmade instrument, the Emotograph, was destroyed in a fire in 1924, and on 2 February 1935 he made the first use of his Keeler Polygraph, on two criminals in Portage, Wisconsin. He worked at the Scientific Crime Detection Laboratory at Northwestern University from 1930 and headed it from 1936 to 1938, then entered private business, opened the first polygraph school, the Keeler Institute, and became the first full-time private polygraph consultant. He died in Door County, Wisconsin, at the age of 45.