Lie Detection Technique in India

The lie detector test is a kind of test where the person is subjected to a certain test where certain physiological characters are taken into consideration. It bases the result of the test on any changes in those characters than in any other normal situation as we believe it that certain features of a person change when he lies. The other name of this test is the Deception Detection Test. We consider them to be useful during investigations to generate more clues.

The maxim Nemo tenetur seipsum provider, no one is bound to accused against himself and thus the principle of protection from self-incrimination was introduced. It was on the presumption of innocence.

Article 20(3) [i] of the Indian Constitution and Section 161 (2) of the Code of Criminal Procedure have given the protection to the accused person from self-incrimination. The Polygraph Test doesn’t use any force. Article 20 (3) supports the principle of Presumption of Innocence of the subjected person in any criminal case where the burden of proof lies on the prosecution. Hence it could also be said that the use of the Lie Detector test would cause the Principle’s violation of Self Incrimination guarded by Article 20(3).

Polygraph Test

The Polygraph test is based on the recording of certain physiological activities such as blood pressure, perspiration, respiration rate and depth, psychogalvanic skin reflex (skin resistance to electrical current) to frame an opinion on is the person who is being tested is telling the truth or not. The biggest drawback of the test is that the results are mere assumptions. Therefore, the result isn’t taken as evidence in most jurisdictions. There is no Indian legislation which carries “Polygraph Test” and hence can’t be declared as valid. The Polygraph machine presents time gauge and chosen psychological behaviour or electro psychological behaviour.

Legal Provisions

Code of Criminal Procedure –

  • Section 53(1) of the Code of Criminal Procedure (Cr.P.C) enables the medical examination of the accused by any medical practitioner when the police request. Section 53 (1) of the Code of Criminal Procedure says – “when a person is an arrest on a charge of committing an offence under such circumstances that there are reasonable grounds for believing that an examination of the person will afford, evidence as to the commission of an offence, it shall be lawful for a registered medical practitioner, acting at the request of the police officer snot below the rank of sub-inspector, and for any person acting in good faith in his aid and under his direction, to make such an examination of the person arrested as is reasonably necessary to determine if the facts which may afford such evidence, to use such force as is reasonably necessary for that purpose”. The point to note here is that this section allows the forensic science to get an entry into a criminal investigation.
  • Section 161 (2) of the Code of Criminal Procedure (Cr.P.C.) protects the rights of the citizen against self-incrimination. Section 161 (2) of Cr.P.C says – “every person is bound to answer truthfully all question, put to him by  a police officer, other than the question the answer to which, would have a tendency to expose that person to a criminal charge, penalty or forfeiture.” The right to remain silent is granted to the accused and no extraction of statements can be done forcibly.

The Indian Evidence Act, 1872 –

  • Section 3 (1) has the definition of “Evidence” as – (1) All statements which the court permits or requires to be made before it by witnesses, in relation matter of fact under inquiry; (2) All documents including electronic records produced for the inspection of the court; Such documents are called documentary evidence.

Hence, the statements under the Polygraph Test or any Narcotics Test can’t be treated as Evidence as they aren’t mentioned and not guarded by any of the conditions as stated above. Another point to note would be that many statements taken under the Narco-analysis test would not be voluntary and it takes any statement while the person under self-consciousness can’t be given the status of evidence under the law.

Guidelines of National Human Rights Commission

On 12 November 1997, the National Human Rights Commission came up with a set of guidelines relating to the Polygraph Test or the Lie Detector Test because there was an increasing number of complaints regarding the conduct of the test which also involves a certain drug administration in the body of the subjected person.

• it only conducts The Lie Detector Test on the consent of the accused. If the person denies, they should conduct no such test.

• After the accused agrees for the test, he shall be assisted by a lawyer and all implications of the test, such as the legal implication, physical and emotional implication should be told to him by either the lawyer or the police.

• it can only record The consent given by the accused before a Judicial Magistrate. 

• A lawyer to represent the accused who have agreed for the Lie Detector Test while the hearing before the Judicial Magistrate.

• The statement made shall have the status as any other statement made in front of the police and it will not be a confessional one. This shall be told to the subjected person before the test.

• All factors which relate to the Magistrate shall consider the detention of such as the length of the detention.

• The Lie Detector Test should be conducted in the presence of a lawyer and the responsibility of recording the test should be given to an independent agency.

• The medical and factual narration of the manner of the information should be on the record.

Case Laws

In Jitubhai Patel v. the State of Gujarat, When the state filed the affidavit that they shall not conduct the Polygraph Test on the accused without the prior consent of the accused, it made the use of scientific evidence only academic. In the mentioned case, they held it that the Polygraph Test and Narco-Analysis Test can be conducted with no consent of the accused. The point to look over here is that these tests are not physical tests such as those of fingerprints and DNA testing. The Polygraph Test and Narco-Analysis Test are more than physical tests.

In Selvi v. State of Karnataka, the question about the relevancy of the Polygraph Test was before the court. The court has to decide the constitutionality of conducting the Polygraph Test on the accused without his/ her consent. They observed it that Article 20(3) protects an individual and his/ her choice whether to speak or to remain silent irrespective of anything else. The idea behind Article 20(3) of the Constitution of India is to prevent any forcible conveyance of personal knowledge which may or may not apply to the case at hand. The result out from the impugned test has a testimonial character and the result can’t be treated as material evidence. In the mentioned case, the Supreme Court laid down certain guidelines regarding Polygraph Test. They also held it they shall not conduct the Polygraph Test on the subjected person without his/ her consent. Any such test if conducted would cause the violation of Article 20 (3) of the Indian Constitution.

In Ram Singh v. Sonia & others,  the Supreme Court that we shall not treat the Polygraph Evidence as per Section 45 of Evidence Act held it. They could not admit it in any court. Further, while cross-examining one can use the Polygraph Test to come out to the true picture and truth of the event.

With Sasntokhben Sharmanbhai Jadeja v. the State of Gujarat, the court cleared that the use of statements during the Narcotics test can help or assist during the investigation process but not as any evidence under the court of law. We could use the statements to further help the investigation agency during the investigation process to gather more evidence. There will be no bar of Article 20 (3) of the Indian Constitution on conducting the Narco-Analysis test on the accused. It was also observed that Section 156 to 159 of the Code of Criminal Procedure deals with collecting evidence and is protected under the law and therefore, conducting the Narco-Analysis Test should be treated as a part of the collection of evidence. In the mentioned case, it involved the accused in a fake stamp case. When the accused was brought for a polygraph test and interviewed, they saw it that the person was lying about the involvement of the police officer and the politician in the case. Then when on the next day it went him through the Brain Mapping Test. They held it that the report seems to be vague and it could make no reliance on any of the statements. Hence, it was declared that where the scientific tests are done, it bases its admissibility on its authenticity.


India has no directly defined legal provisions for the Lie-Detection test. The only way to determine the continuality of the lie detection tests, Section 161 of the Code of Criminal Procedure and Article 20 (3) of the Indian Constitution is to be seen. It does not include the statements recorded in any of these tests in the definition of “evidence”. We do not consider the statements being voluntary as these tests involve the administration of certain medications in the person. NHRC has given guidelines about how this test is conducted. Court of law has not treated the statements got from this test as admissible but had allotted them the status of “clues”.

Frequently Asked Questions (FAQs)

Ques 1: In Polygraph Test which we test all aspects of Human Physiology?

Ans: a) Pneumographic tracing b) Electrodermal activity tracing, and c) Cardiovascular tracing.

Ques 2: What are the objectives of Lie Detection technique?


• To verify the statements of the subjected person

• To economies and speed up the process of investigation

• Scientific interrogation in white collar crimes.

• To corroborate the findings of investigation

Ques 3: Is there any possibility of any adverse effect of the Narco-Analysis test?

Ans: There is a very rare possibility of a harmful effect of the Narco-Analysis test. It may only cause harm when any medicine which isn’t prescribed by the doctor is administered into the person.

Ques 4: What is the Section 156 of Code if Criminal Procedure?

Ans 5:

156. Police officer’ s power to investigate cognizable case.

(1) Any officer in charge of a police station may, without the order of a Magistrate, investigate any cognizable case which a Court having jurisdiction over the local area within the limits of such station would have the power to inquire into or try under Chapter XIII.

(2) No proceeding of a police officer in any such case shall at any stage be called in question because the case was one which such officer was not empowered under this section to investigate.

(3) Any Magistrate empowered under Section 190 may order such an investigation.

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