A law enforcement polygraph examination involves a structured series of inquiries designed to assess the veracity of a subject’s statements. These questions are categorized into three primary types: irrelevant, relevant, and control. Irrelevant inquiries are neutral and unrelated to the matter under investigation, serving as a baseline for the subject’s physiological responses. Relevant inquiries directly address the core issues of the investigation, seeking to elicit responses indicative of deception if untruthful. Control inquiries are designed to provoke a physiological response, acting as a comparison point against which reactions to relevant inquiries are measured. For instance, an irrelevant question might be, “Is the sky blue?” A relevant question could be, “Did you participate in the robbery of the First National Bank?” A control question might be, “Have you ever stolen anything in your life?”
The significance of these examinations lies in their potential to aid investigations by identifying deceptive responses and corroborating truthful accounts. Historically, this technique has been employed to narrow suspect pools, gather additional investigative leads, and encourage confessions. The information derived from physiological responses during questioning can significantly contribute to the overall assessment of a person’s involvement in a specific incident, although its admissibility in court varies by jurisdiction.
