E1288 - The Truth Machine

Leonarde Keeler, inventor of the modern polygraph, first showcased his device in a courtroom on 2nd February, 1935. The wooden box, which measured physiological responses like blood pressure and respiration, took the stand alongside him, and, while Keeler emphasized the machine wasn’t infallible, he later told journalists assembled outside the venue that his invention would soon revolutionise criminal justice.

Keeler’s innovations built upon earlier work by others, including Scottish cardiologist James McKenzie, who created a device to detect heart arrhythmias, and Dr. William Moulton Marston, who later linked blood pressure changes to emotional responses - and, insp...