who created the modern-day lie detector test
An earlier and less successful lie detector or polygraph machine was invented by James Mackenzie in 1902. However, the modern polygraph machine was invented by John Larson in 1921. John Larson, a University of California medical student, invented the modern lie detector (polygraph) in 1921. Used in police interrogation and investigation since 1924, the lie detector is still controversial among psychologists, and is not always judicially acceptable.