Introduction & Background
Criminal justice is a field whose entire purpose is to remain restless in its search for truth and justice. This restlessness has, over the last few decades, given law enforcement many innovative techniques to pursue evidence and find out the truth. Be it the revolutionary Fingerprint and DNA analysis techniques or the particularly controversial, Deception Detection Tests like polygraphs, brain mapping and narco-analysis, which are being used by Law enforcement agencies worldwide. These tools attempt to read the reactions and responses the body or mind of their test subjects make to being asked pointed questions in situations of pressure. Conventional questioning reads the words of its subject, which can be easy to mask. This piece of innovation does not want to has attracted a large amount of critics, majorly because the science behind them is standing on a four legged stool with only one functioning leg, that being, their results are often inadmissible, and the questions they raise about fairness and dignity are ones courts keep coming back to.[1]
Narco analysis or Narco Tests have become a major topic of examination and scrutiny by both the general public and the legal fraternity, because of their use of intrusive procedures, like registering relaxants to temporarily incapacitate people into providing information that they would never otherwise divulge with anybody or cannot divulge due to extenuating circumstances.[2]
Robert House tested the concept in its inaugural attempt in 1922 but it was introduced to India during the probe of the tragic Godhra train disaster of 2002. The use of narco-analysis in this case, along with the Arun Bhatt kidnapping and the Telgi scam of 1993, sparked a huge debate and highlighted critical concerns about ethics, legality, and the character of truth in context of criminal justice and it has been called into question numerous times over the years in cases such as the Dinesh Dalmia case[3], the Arushi Talwar Murder case[4], the Ramchandra Reddy case[5] and perhaps the most famous, the Selvi vs. State case[6].
Naturally, one can assume that the higher judiciary has a lot to say about the validity and implementation of this criminal investigative approach and the case of Amlesh Kumar v. State of Bihar[7] continues in this vein. Amlesh Kumar is suspected of being engaged in his wife’s unexpected abduction as well as dowry-related maltreatment. As a result, his in-laws filed a First Information Report (FIR) against him under the Indian Penal Code. While the Patna High Court reviewed Kumar’s bail plea, it permitted narco-analysis tests for himself as well as the witnesses he had, but the Supreme Court eventually declared this practice illegal, emphasizing that such exams should not be the major foundation for conviction.[8]
Legal and Constitutional Context
Two constitutional provisions anchor this debate. Article 20(3) of the Indian Constitution guarantees that no accused person can be compelled to be a witness against themselves. This is a fundamental right, therefore the legal system simply cannot deploy mechanisms designed to extract self-incriminating statements by force or chemical coercion. Article 21, which protects life and personal liberty, has been read broadly by the Supreme Court to cover privacy, dignity and access to fair proceedings.[9] In Selvi v. State, the court determined that involuntary tests, including narco-analysis, polygraph tests, and brain mapping, were in violation of Articles 20(3) and 21 of the Constitution.[10]
This is because they violate a person’s mental autonomy by gathering statements without authorization.[11] The court directed that voluntary, informed permission be acquired prior to conducting these tests, with documentation by a magistrate[12]. In its recent decision, the Supreme Court reiterated that coercive narco-analysis is fundamentally prohibited, and that even consensual findings from this kind of testing cannot be used as physical proof in court. The Supreme Court stressed that coerced narco-analysis is prohibited.It said that even results from tests conducted with voluntary consent should not be used as evidence in court. This decision guarantees constitutional rights contrary to invasive investigative procedures, particularly during bail hearings. Even if somebody voluntarily takes such a test, its outcomes cannot be presented as credible evidence in court. The SC for the first time in such uncertain terms recognized that involuntary tests invade personal mental privacy and coerces confessions without consent. This is a violation of the dignity and human rights of the accused.[13]
[1]Senthil Kumaran M, Bedanta Sarma & Arun Kumar S, Deception detection tests: A subdued investigating tool, 8 International Journal of Research and Review 419–422 (2021). https://www.ijrrjournal.com/IJRR_Vol.8_Issue.11_Nov2021/IJRR053.pdf
[2]Jyaditya Dogra, Narco analysis: A comparative study with respect to India and Western countries, Journal of Legal Subjects 7–13 (2023). https://journal.hmjournals.com/index.php/JLS/article/view/3303/2728
[3]A. Mathur, State of West Bengal vs Dinesh Dalmia on 25 April, 2007jajharkhand.in,
https://jajharkhand.in/wp/wp-content/judicial_updates_files/07_Criminal_Law/15_order_of_remand/State_Of_West_Bengal_vs_Dinesh_Dalmia_on_25_April,_2007.PDF (last visited Jan 12, 2026).
[4]Divyani Rattanpal, The curious case of narco tests in Aarushi-Hemraj Murder MysteryTheQuint (2017),
https://www.thequint.com/news/india/the-curious-case-of-narco-tests-in-aarushi-hemraj-murder-mystery (last visited Jan 12, 2026).
[5]A. S. Dalal, and Arunava Mukherjee. “Constitutional And Evidentiary Validity Of New Scientific Tests, 4 Journal of the Indian Law Institute, 529–42 (2007)
[6] Selvi & Ors vs State of Karnataka & Anr. AIR 2010 SUPREME COURT 1974
[7] Amlesh Kumar Vs. State of Bihar SLP (Crl.) No. 5392 of 2024
[8]Amlesh Kumar Vs. State of Bihar , sci.gov.in (2025), https://api.sci.gov.in/supremecourt/2024/9701/9701_2024_4_1501_62184_Judgement_09-Jun-2025.pdf (last visited Jan 12, 2026).
[9] Prashant Kanha, Narco-Analysis Constitutionality in India: 2025 Supreme Court Ruling on Consent, Rights, and Legal Admissibility Explainedprashantkanha.com (2025),https://www.prashantkanha.com/narco-analysis-constitutionality-in-india/ (last visited Jan 12, 2026).
[10] K.G. BALAKRISHNAN, R.V. RAVEENDRAN & J.M. PANCHAL, SMT. SELVI & ORS. v. STATE OF KARNATAKAcdnbbsr.s3waas.gov.in,
https://cdnbbsr.s3waas.gov.in/s3ec0490f1f4972d133619a60c30f3559e/documents/aor_notice_circular/26.pdf (last visited Jan 12, 2026).
[11] Selvi vs. State of Karnataka (2010), https://privacylibrary.ccgnlud.org/case/selvi-vs-state-of-karnataka (last visited Jan 12, 2026).
[12] Riya Rathore, Supreme Court: No indefeasible right with accused to undergo narco-analysis test; but can apply to court Verdictum (2025),
https://www.verdictum.in/court-updates/supreme-court/accused-has-a-right-to-voluntarily-undergo-a-narcoanalysis-test-2025-insc-810-amlesh-kumar-v-state-of-bihar-1580476 (last visited Jan 12, 2026).
[13] “under no circumstances, is an involuntary or forced narco-analysis test permissible under law”; SC sets aside Patna High Court’s order permitting involuntary test, SCC Times (2025),
https://www.scconline.com/blog/post/2025/06/10/sc-sets-aside-patna-high-court-order-permitting-forced-narco-analysis-test/ (last visited Jan 12, 2026).