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Narco-Analysis and its position in the Indian Judiciary


Criminal investigations and inquiries are based on one single motive- to find the truth. Though there has been an increase in the number of third degree tortures by Police officials on the accused to elicit principle and key details, technological advancements are used in arduous situations when the accused won’t take yes as an answer and are unwilling to provide confessions.

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Science and technological advancements have led to the invention of state of art tools to extract confessions to avoid miscarriage of justice. Some of these devices include the truth serum test, the Polygraph test and the Brain Mapping test. These psychoanalytical tests also known as the Deception Detection Tests (DDT) are used to define and observe the accused’s behavior that is later used to authenticate statements are have important scientific, legal &ethical implications

 Truth serum test: the test uses a wide range of psychoactive drugs like sodium pentothal and sodium amytal, commonly known as barbiturates, to extract truthful confessions.

Polygraph test: often referred as the lie detector test, is a procedure that records a person’s several physiological indexes like Blood pressure, heart rate etc. while interrogating or questioning them. This test is majorly debated and results are quite erroneous.

Brain mapping test: commonly known as P 300 test, this test uses a set of neuroscientific techniques to find whether an accused is concealing certain facts.

Procedure for Narco-Analysis

Narco-analysis is conducted on accused or suspects only after a prior permission is sought from the courts & written consent is affixed. 3 grams of sodium pentothal is dissolved in 300 grams of distilled water and is administered intravenously in the body of the accused/suspect under the supervision of an anesthetist. Also, physiological indicators like blood pressure, heart rate are monitored continuously throughout the procedure to maintain optimum levels in the subject’s body. Later the subject falls in a twilight stage i.e. between conscious and unconscious levels where it is highly difficult for him to lie over the questions that are posed before him in the interrogation session.

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Legal Implications of DDT’s

Though, Narco analysis endures to elicit truth in a criminal investigation, such tests result in invasion of a person’s body. Such tests are held not admissible in the court of law since it is made by a semi-conscious person and are mostly against the will of a person, hence infringe Article 20(3) of the constitution.

The Maxim “Nemo Tenetur se Ipsum Accusare” reads as ‘No man maybe compelled to answer any question that may prove him guilty of a crime which he has been accused of’. If a confession is obtained under physical or moral compulsion or subjecting him to hypnosis treatment must be rejected by the court taking the fundamental rights aspect of the person undergoing the test. Article 20(3) of the Constitution of India, deals with the privilege of an accused against self- incrimination and is also a fundamental Canon in criminal jurisprudence. Hence subjecting an accused or suspect to undergo narco analysis is a violation of Article 20(3).

The legal statue of narco analysis test Involves question on the aspects of both fundamental rights and human rights. The right against self-incrimination is also enshrined in the Code of Criminal Procedure under section 161.The Right to remain silent laid down in the Constitution was well observed in the case of Nandini Sathpathy v. P.L.Dani[1], where the court held that, an accused has the right to remain silent and forego from giving statements under compulsion, coercion or threat. DDT tests also nullify the legitimacy of Article 20(3) and Section 161 of the Cr.P.C.

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These tests also include mental torture and violate the right of life under Article 21 of the Constitution as well. Right to privacy is also infringed by administration of these tests by forcefully recovering statements from the accused without his consent. Also, administration of these drugs can cause injury since they’re fatal in nature and could attract criminal liabilities and charges.

Controversy over the Legality of Narco Analysis

The Madras High Court in the case of Dinesh Dalmia v. State[2] held that, the investigation in a case must be completed within a reasonable time, otherwise the benefit of delay will be provided to the accused and if he fails to co-operate with the investigation, then such truth or confession may be sought from him using sophisticated scientific methods. Owing to the same reason as stated the above, the court in the case of Sh. Shailender Sharma v State[3], held that such scientific methods don’t hold any constitutional infirmity and are major aids in investigation procedures.

These judgments stated above upheld the legality of DDT’s until the major breakthrough was put out by the Indian Judiciary in the landmark case of Smt. Selvi & Ors. v. State of Karnataka[4] where in the use of DDTS’s were questioned pertaining to Article 20(3) and article 21 by the Supreme Court

It was also held by the Hon’ble Supreme Court that such techniques violate boundaries of privacy and in cases of involuntary confessions, fall under the scope of testimonial compulsion thereby attracting the ambit of Article 20(3)

The Court finally ruled that such tests though voluntarily administered cannot be admissible in the court of law since the accused does not have control of his mind during confessions by using these techniques. But any other material evidence sought subsequently with the help of these tests can be admissible in the court of law under Section 27 of the Indian Evidence Act.

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The debate over the reliability of these tests is going on till date but using these techniques incorrectly would result in travesty of justice. It has been criticized at large in several countries like the US where these tests are not found to be 100% accurate. Scientific inventions and sophisticated devices used in investigation processes may aid in investigation procedures but may lead to infringement of rights and mistrial if not properly administered

[1] Nandini Sathpathy v. P.L.Dani, 1978 SC 1025 (India).

[2] Dinesh Dalmia v. State, Crl. R.C. No. 259 of 2006 (India).

[3] Sh. Shailender Sharma v. State, Writ Petition (Crl.) 532 of 2008 (Delhi HC) (India).

[4] Smt. Selvi & Ors. v. State of Karnataka, (2010) 7 SCC 263 (India).

Cite this article (The Bluebook 20th ed.)-

Soundarya Mathavan, Narco-Analysis and its position in the Indian Judiciary, Ex Gratia Law Journal, (August 16, 2020),

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Soundarya Mathavan
Student - School of Excellence in Law, The Tamil Nadu Dr. Ambedkar Law University.