First Polygraph Used

Early PolygraphFebruary 2, 1935

Leonarde Keeler, co-inventor of the polygraph machine, first uses his invention. Keeler used the lie detector on two criminals in Portage, Wisconsin, who were later convicted of assault when the lie detector results were introduced in court.

  • Simon Webb

    The image shown is not a lie detector, it is a device for duplicating handwriting also known as a polygraph.