Narcoanalysis: Importance in Criminal Investigation

Narcoanalysis test is one of the strategies of Deception Detection Tests (DDTs) which is employed by criminal investigation system, to interrogate the accused and to extract the information and truth behind the crime committed from the subject.
The present article is an attempt to deal with the aspects of narcoanalysis test, their advantages and disadvantages. The paper will also try to explain the legality and admissibility of the evidence obtained with the help of Narcoanalysis test, its constitutional and evidentiary validity.


The term Narcoanalysis is derived from Greek word ‘narke’ (meaning anaesthesia) and is a psychotherapeutic technique that uses psychotropic drugs to crate great diminution of sensibility. The fair trial and conviction in criminal cases depends upon the proper investigation, interrogation of witnesses and collection of evidences by the investigating officers. It is undemanding and easy for the investigators to collect the evidences and information from the crime scene and to interrogate the witnesses than extracting the hidden information. The hidden information is extracted from the human by the Deception Detection Test, which includes Polygraph, Brain Mapping and Narcoanalysis Test.
Narcoanalysis test generally don’t have legal validity as under this test the person goes into the unconscious state in which mental element with a strong associated affects come to the surface where they can be exploited by the investigating agency and speaks whatever is present in their mind, and therefore are not admissible in court. The legal position of applying this test as an investigative aid arises issues like encroachment of an individual’s liberties, rights, and freedom. But the apex court never absolutely denied the use of this test in criminal investigation, on the whole Indian Judiciary has consented limited and conditional use for extracting truth. Thus, in complicated criminal cases, the scientific methods like Narcoanalysis test can  be utilized for the benefits of the society at large and to have a crime free society, to trace the involvement of criminals, to cross check the findings of the case and to determine whether suspect made the true statement or not.

Narcoanalysis Test as per Provisions of Constitutional Law and Evidence Law

One of the fundamental principles of criminal justice system is based on the maxim ‘nemo tenetur seipsum accusare’ which means no person is bound to accuse himself.
The Constitution of India has clearly stated under Article 20(3) that a person cannot be forced to be a witness against himself. The provision established the preposition such as, accused is presumed to be not guilty, prosecution has to establish the crime and guilt of the accused person, and accused against his will need not to make any statement. The ‘Right against Self-Incrimination’ i.e. Right to Silence is provided by Article 20(3), section 161(2) of the CrPC deals with the protect against self-incrimination for every person. The test against the will of the accused would be violative of Article 20(3) of the Constitution, but if the test is given voluntary and with the consent of the accused then it will not come under violation of Article 20(3).
The present criminal justice system is based on the famous judicial dictum that “let the hundred guilty go unpunished rather than an innocent being punished”, hence it is more towards to the accused and obsessed with individual liberty, due to which the evidences are diluted easily. The Evidence prospective is classified into two parts i.e. admission and confession. The main issue is that the evidences collected from the test hit by Section 25 and 26 of the Indian Evidence Act, 1872. But if the test will be conducted in the presence of the magistrate then it would be a valid confession and it will not violated Section 25 and 26.
The permissions required for the administration of Narcoanalysis test are:
a) Permission of the magistrate is to be taken to carry out the said test,

b) Fitness of the subject, the general physician has to issue a certificate of well-being of the person.

c) Consent of the subject is also obtained to satisfy the need of Article 20(3).

The Narcoanalysis test was came to India in 1936 and first time it was conducted in the Godhra case, in the year 2002. Since then, Courts have been given several rulings and judgements from time to time for the admissibility and legality of the Narcoanalysis test.
In Selvi v. State of Karnataka[1], the Supreme Court has laid down the provision about conducting of Narcoanalysis test that the test cannot be conducted on the accused person without taking their consent. If the test is conducted on the accused person, it would violate Article 20(3) of the Indian Constitution. Further, it was held by the court that this test should be conducted in the presence of the expert.

In State of Gujarat v. Anirudh Singh[2], the SC held that, it is statutory duty of every witness who has consciousness of commission of crime to assist the state in giving evidence and it seems justified that if a person to not willing in providing information which is necessary for investigation purpose then adverse impression must be taken against them and it would not violate Article 20(3). In this way, the court harmonised balance between protection given under constitution and Narcoanalysis.

In Dharampal v. State[3], the SC said that the criminal justice system cannot function properly if the person living in the society would not be cooperative in the investigation. Therefore, it is the duty of every person to assist the state in bringing criminal justice and no one can escape from social responsibility and withhold criminal information in the name of right of privacy which itself is not an absolute right.

In the case of Dinesh Dalmia v. State[4], the Madras High Court held that the scientific test such as Narcoanalysis test, Polygraph and Brain-mapping conducted on accused for the investigation purpose and to bring out the truth would not violate the right to remain silent.

In the case of Nandini Satpathy v. P. L. Dami[5], the SC said that no one can extract statements and information from the accused, who has right to silence during the course of investigation. It was claimed and upheld by the apex court that the right to keep silence is by the virtue of Article 20(3) of the Indian Constitution and Section 161(2) of Criminal Procedure Code.

In Rojo George v. Deputy Superintendent of Police[6], the Court allowed the Narcoanalysis test with the opinion that in present day, the criminals started to use various modern techniques for execution of crime, and the traditional method of investigation and interrogation isn’t enough and will not be successful, so there is need to utilize some scientific new techniques such as DDT. Court also held that when such techniques used in the presence of expert then it cannot be raised that the fundamental human rights of any citizen of India is violated by investigating agencies.

In the case of Mohinder Singh Pandher and Surender Singh Koli v. State of U.P.[7], in which Narcoanalysis test was conducted on Mohinder Singh Pandher and Surender Koli in 2007, who were the main accused in the famous Nithari Killing case, The test was basically conducted to discover the veracity of their statement given during custodial interrogation. During the test, the accused person disclosed the name of many females and children who had been murdered by them and also revealed the reason and his argue to rape them after murdering them. By the conducting of this test many important and relevant information were disclosed to the investigating agencies.

Hence, the constitutional validity of this test lies in the hands of judiciary, and there is a balance between societal interest and interest of private individual.


  • To encourage the investigating authorities, there is need to give a choice of modern instruments and scientific techniques which can be used when there is total impossibility to find further evidence.
  • The scientific technique such as Narcoanalysis test can replace traditional technique for extracting truth from accused by third degree which is exceptionally grievous which infringe the rights of people.
  • By looking the present distressing state of society with respect to crime, criminals, wrongdoing rate and influenced blameless persons, it is by all accounts, the correct time to check the routes by which this can be diminished. It is achievable by giving rich innovation to the investigating agencies and introduction of scientific methods including Narcoanalysis test.
  • In complicated criminal cases, when the authorities are not in a position to find out the guilty and the truth, the scientific methods like Narcoanalysis test can be used to trace the involvement of criminals and their intentions.
  • The evidence extracted from the accused through this procedure can be utilized to get a permissible evidence, to prove and to correlate with other evidences.
  •  The test also acts as an aid in the determination of individual participated in the terrorist activity directly or indirectly.

In India, the conviction rate is very low whereas on the other hand the crime rate is very high and the main reason responsible for this gap is poor investigation. Our criminal justice system needs to raise capability and sophistication in the investigation process and include new scientific methods and techniques.


  • In the procedure of Narcoanalysis test, the chemical is administered in the body of a person so the dose of the chemical is decided according to physique, mental capability and will power of the person. The wrong dose of chemical may lead to state of coma or even results in death of the person.
  • If the person is drug addicted, then the process will be not as much successful as need for extracting truth and collection of evidence.
  • The question of reliability of information given by the subject can also be raised as the information is collected by the subject in their semiconscious stage.
  • The constitution of India provides Article 20(3) which clearly says no person shall be a witness against himself, therefore the process may declare as a violation of fundamental rights of the Constitution.
  • Section 25 of the Indian Evidence Act, 1872 talks about confession made by a person under police custody could not be admitted as evidence. It means there would be possibility of non-admissibility of evidence. The Narcoanalysis test conducted in the presence of magistrate then it will be constituted as a valid confession.


Law is a living process and therefore not static which evolves according to the change in society, development of science and technology, ethics and so on. In India, the criminal justice system has an alarmingly low conviction rate and the situation needs to be rectifying with importance on actual science and state of modern technology. The legal judiciary system should imbibe the advances and developments that take place in science as long as they are good for the society and do not violate the fundamental legal principles. Narco-analysis, for the criminal investigations has proved to be an effective and valuable technique, which greatly affects both the innocent and the guilty and thereby accelerate the cause of justice. This test should not be used in all kinds of cases, but only in such cases where the interest of society at large is involved. There is a need of the better refined and sophisticated interrogation processes to replace the barbaric third-degree method. The rules of criminal procedure, evidence and the institutional infrastructure designed almost a century ago, are now found inadequate to meet the demands of the scientific world. The manner in which the modern-day criminals make use of science and technology in executing their criminal activities, urged rethinking on the essentials of the criminal justice establishment to seek the help of scientific developments to come to the help of police, prosecutors and the court.


Q.1. How Hidden Information Can Be Extracted from The Human?

Ans. The hidden information is extracted from the human by the Deception Detection Test, which includes Polygraph, Brain Mapping and Narcoanalysis Test.

Q.2. What Are the Permissions Required for The Administration of Narcoanalysis Test?

Ans. The permissions required for the administration of Narcoanalysis test are permission of the Magistrate is to be taken to carry out the said test, fitness of the subject i.e. the general physician have to issue a certificate of well-being of the person and consent of the subject is also obtained to satisfy the need of Article 20(3).

Q.3. When Was Narcoanalysis Test Came to India?

Ans. The Narcoanalysis test was came to India in 1936 and first time it was conducted in the Godhra case, in the year 2002.


Gosia Farooq Khan, Narcoanalysis test: A blessing to criminal justice system, its reliability and admissibility in light of various judgements.  Volume 4; Issue 2; March 2018; Page No. 311-317,individual’s%20rights%2C%20liberties%20and%20freedom.

Ajay Kr. Barnwal, Dr. S. N. Ambedkar, Narco-analysis Test: An analysis of various Judgements of Indian Judiciary, IOSR Journal of Humanities and Social Science (IOSR-JHSS) Volume 19, Issue 10, Ver. I (Oct. 2014), PP 52-57

[1] AIR 2010 SC 340

[2] MANU/SC/0749/1997

[3] MANU/SC/0260/2003

[4] 2006 Crl. L. J. 2401

[5] AIR 1978 SC 1025

[6] AIR 1953 SC 131

[7] AIR 2011 SC 970

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