Which role does a polygraph play in investigations?

A polygraph, commonly known as a lie detector test, plays a crucial role in investigations by recording emotional responses such as physiological changes that occur when a person answers questions. This device measures indicators like heart rate, blood pressure, respiratory rate, and skin conductivity while the individual responds to questions. The premise behind the polygraph is that deceptive answers can produce specific physiological responses compared to truthful ones.

While polygraphs can be useful as investigative tools, they are not definitive proof of guilt or innocence, nor do they analyze physical locations or collect testimonies. Instead, they provide law enforcement and investigators with potential insights into a person's truthfulness based on their emotional responses during questioning.