The recent headlines regarding Imran Khan's refusal to undergo a polygraph test have reignited public discourse around the legal and ethical implications of such investigative techniques. The entry of digital tools like lie detectors into criminal investigations raises important questions: Can a suspect be compelled to undergo a polygraph test without their consent? Are the results of such tests admissible in a court of law?

To address these concerns, it is essential to understand what a polygraph test entails. Commonly known as a lie detector test, a polygraph measures physiological indicators — heart rate, blood pressure, respiratory rate and galvanic skin response — while the subject answers a series of questions.

The assumption is that deceptive responses produce physiological reactions distinct from those linked to truthful answers. However, polygraph testing is not based on an established scientific theory accepted in the field of law or physical science, and thus, its results are not considered conclusive evidence.

The legality of compelling an individual to undergo such a test touches directly upon constitutional protections, particularly the right against self-incrimination and the right to privacy.

In Pakistan, Article 13(b) of the Constitution provides protection against self-incrimination, stating: "No person accused of an offense shall be compelled to be a witness against himself." This constitutional safeguard........

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