"Courts Reject Polygraph Plea, Reaffirm Mental Privacy and Self-Incrimination Protections"
Polygraph
instrument measuring physiological responses (pulse, respiration, skin conductance) to detect deception.
Narco-analysis
pharmacological interrogation using sedatives to induce semi-conscious state and elicit responses.
The Indian Constitution enshrines two interlocking protections that govern the use of forensic interrogation techniques. Article 20(3) guarantees that no person accused of an offence shall be compelled to be a witness against themselves — the right against self-incrimination, rooted in the common-law maxim nemo tenetur seipsum accusare. Article 21 protects the right to life and personal liberty, which the Supreme Court has progressively expanded since Maneka Gandhi v. Union of India to encompass dignity, bodily integrity, and — crucially — mental privacy. Together, these provisions form the constitutional bedrock against coercive interrogation.
The state's investigative apparatus, including the Central Bureau of Investigation, has historically sought to supplement conventional interrogation with scientific techniques — polygraph (lie detector), narco-analysis (truth serum), and Brain Electrical Activation Profile (BEAP) or brain mapping tests. Each technique attempts to bypass a subject's conscious control over their responses: polygraph measures physiological reactions (pulse, respiration, galvanic skin response) to questions; narco-analysis uses pharmacological agents to induce a semi-conscious state; and BEAP measures involuntary neural responses to stimuli. The admissibility and legality of these techniques remained contested until the Supreme Court's landmark ruling in Selvi v. State of Karnataka (2010).
In Selvi v. State of Karnataka (2010), a three-judge bench of the Supreme Court settled the constitutional position comprehensively. The Court held that the compulsory administration of polygraph, narco-analysis, or BEAP tests violates Article 20(3) because these techniques are designed to extract information from a person without their conscious participation — the subject does not choose the answers that emerge. This distinguishes them fundamentally from conventional questioning, where the accused retains the ability to refuse to answer. The Court further held that compulsory administration amounts to an unjustified intrusion into mental privacy under Article 21, and constitutes cruel, inhuman, or degrading treatment under evolving international human rights norms.
The Court drew a critical distinction between administration and reliance on results. Even where a subject voluntarily consents to undergo such a test, the results cannot be admitted as substantive evidence of guilt, because the subject is not exercising conscious control over responses during the test. …
Under which Article of the Constitution of India is the 'Right to Privacy' protected?
Right to Privacy is protected as an intrinsic part of Right to Life and Personal Liberty. Which of the following in the Constitution of India correctly and appropriately imply the above statement ?
With reference to the administration of polygraph, narco-analysis, and Brain Electrical Activation Profile (BEAP) tests in India, consider the following statements:
1.The Supreme Court has held that compulsory administration of these tests violates Article 20(3) of the Constitution.
2.Even voluntary administration of these tests renders the test results admissible as substantive evidence of guilt.
3.Consent for voluntary administration must be recorded before a judicial magistrate.
4.Any physical fact discovered as a consequence of information revealed during such a test may be used as corroborative evidence.
Which of the statements given above are correct?
The Supreme Court in Selvi v. State of Karnataka (2010) held that compulsory administration of narco-analysis tests violates the Constitution. Which of the following pairs of Articles was the primary constitutional basis for this ruling?
Consider the following assertion and reason:
Assertion (A): Even when an accused person voluntarily consents to undergo a polygraph test, the test results cannot be admitted as substantive evidence of guilt in an Indian court.
Reason (R): The subject does not exercise conscious control over their responses during the test, which distinguishes it from a voluntary statement or conventional interrogation.
Which of the following is correct?
Under Section 23 of the Bharatiya Sakshya Adhiniyam (BSA), which of the following is the correct position regarding confessions made to a police officer by a person in custody?
The Supreme Court in Amlesh Kumar v. State of Bihar (2025) set aside a High Court order permitting narco-analysis. Which of the following best captures the Court's reasoning?
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