In 1902 a non relieable lie detector test was invented by a man named James McKenzie and in 1921 john larson invented a more modern and accurate polygraph.Also john larson was one of the first american police officers to have an academic doctorate.The lie detector that he invented was used to determine if a person was telling the truth or not. His invention records the different body responses while the person is being questioned. If the person lied the persons amount of stress produced changes and the needle records a jump in the person's heart rate on the paper it is writing on.