Abstract

This review critically analyzes the validity, ethical issues, and legal aspects of polygraph examination used in forensic and criminal justice applications. Though formulated to identify deception based on physiological measures like heart rate, skin conductivity, blood pressure, and breathing, the accuracy of polygraph ranges between 70% and 90%, depending on the expertise of the examiner and the circumstances. Physical reactions are non-selective for deception and may additionally be influenced by stress, fear, or medical conditions, causing false positives as well as false negatives. Judicial judgments, including Selvi v. Karnataka, stress the significance of free will and privacy protection, restricting the admissibility of polygraph findings as evidence before the court. In comparison, statements of confession are also subject to external influences, social influence, and psychological biases, affecting their evidentiary value. Deletion tests, as auxiliary technologies, ought to be used as part of a whole investigative strategy, upholding the rights of individuals as well as the limitations of science. The review also points to the requirement to incorporate technological innovations, statutory changes, as well as ethical measures to provide more accurate and equitable applications of deception identification technologies in forensic practice.