Leonarde Keeler

Leonarde Keeler
Leonarde Keeler testing his lie-detector on a former witness for the prosecution at the trial of Richard Hauptmann in 1937
Born	(1903-10-30)October 30, 1903 North Berkeley, California
Died	September 20, 1949(1949-09-20) (aged 45) Door County, Wisconsin
Alma mater	University of California, Berkeley University of California, Los Angeles
Occupation(s)	Detective, inventor
Known for	Co-inventor of the polygraph
Spouse	Katherine Applegate ​ ​ (m. 1930; died 1944)​

Leonarde Keeler (October 30, 1903 – September 20, 1949) was the co-inventor of the polygraph. He was named after the polymath Leonardo da Vinci, and preferred to be called Nard. He was a Berkeley high school student and amateur magician. He was captivated by John Augustus Larson's machine, a "cardio-pneumo psychogram", with the goal of detecting deception, and worked on it to produce the modern polygraph.^[1]