Forensic Science Practice Test 2026 – Complete Exam Prep

John Larson is linked to the early development of the polygraph. He built the first practical lie detector and demonstrated how recording multiple physiological signals—such as breathing, heart rate, and skin conductivity—while a person answered questions could reveal deception. By comparing responses to relevant questions with an established set of control questions, Larson showed that deceptive answers could produce distinct physiological patterns. This pioneering approach laid the groundwork for modern polygraph testing and influenced how later researchers and investigators refined the instrument and testing methods.

Karl Landsteiner is known for discovering blood groups, Henry Lee is a contemporary forensic scientist, and William Bass is a forensic anthropologist who studies human remains.