Narco Analysis : Unearthing the Truth

BY Taniya Jaiswal | September 10, 2020

Narco Analysis : Unearthing the Truth

There are several methods for crime investigation, to detect lying and deception by suspect and accused. The modern techniques like polygraph, narco – analysis and brain mapping test are non invasive method that will detect deception without causing physical or mental injury to the subject. Scientific techniques are necessary for proving the guilt as well as innocence of the accused. Narco – Analysis is one such scientific progress that has become an increasingly, common in India. 


The term Narco-Analysis is derived from the Greek word narko ( meaning anesthesia or Torpor) and is used to describe a diagnostic and psychotherapeutic technique that uses psychotropic drugs, particularly barbiturates. 

This technique is used for investigation purpose

It is a process of abreaction or catharsis

Also known as Truth Serum Or Drug Hypnosis or Narco interview technique. 

Hypnosis is induced by using barbiturates or other psychotropic drug as a means of releasing repress feelings. 

Technique effective in two ways – 

1. Therapeutic

2. Rehabilitative

History of Narco-Analysis

The term Narco – analysis was coined by Horseley. In 1922 first time used in criminal investigation in US, when Robert House, a Texas obstetrician used the drug Scopolamine on two prisoners. A truth serum is a psychoactive medication used to obtain information from subjects who are unable to provide it. 

Principle of Narco-Analysis 

By using imagination a person is able to lie. 

In this test, subject’s imagination is neutralised by making him/her in semi conscious. 

In this state, it becomes difficult to lie and answer would be restricted to facts that he/she is already aware of 

Expert inject the subject with Sodium Amytal. 

The dose is dependant on the person’s sex, age, health and physical condition. 

A wrong dose can result a person going into a coma or even death. 

The subject is not in a position to speak up on his own but can answer specific, simple questions. 

The answers are believed to be spontaneous as a semi conscious person is unable to manipulate the answers. 

Team of Experts

Clinical forensic psychologist



Audio – videographer


Supporting nursing staff

How the Narco-Analysis test is conducted? 

Narco-analysis test is conducted by mixing 3 grams of Sodium Pentothal or Sodium Amytal dissolved in 3000ml of distilled water. The dose is calculated as per Kg. of the body weight of the subject and the drug is pushed by an Anesthetist ( a medical doctor) at the rate of 4ml/min ( 100 mg/ min) of a 2.5% solution of Sodium Pentothal. Narco test refers to the practice of administering barbiturates or certain other chemical substances, most often Sodium Pentothal, to lower a subject’s inhibitions in the hope that the subject will more freely share information and feelings. In the narco-analysis test, the subject’s inhibitions are lowered by interfering with his nervous system at the molecular level. In such sleep like state efforts are made to obtain probative truth about the crime. Experts inject a subject with hypnotic like Sodium Pentothal or Sodium Amytal under the circumstances of the laboratory. The dose is dependant on the person’s sex, age, health and physical condition. 

Wrong dose can send the subject into coma or even result in death. The rate of administration is controlled to drive the accused slowly into a hypnotic trance. The effect of the bio molecules on the bio activity of an individual is evident as the drug depresses the CNS ( Central Nervous System) , lower blood pressure and slows the heart rate, putting the subject into hypnotic trance resulting in the lack of inhibition. The subject is then interrogated by the investigating agencies in the presence of the doctors. The revelations made during this stage are recorded both in video and audio casettes. The report prepared by the expert is used in the process of collecting evidence. This procedure is conducted in government hospitals, after a court order is passed instructing the doctors or hospital authorities to conduct the test. Personal consent of the subject is also required. 

Active Chemical Substances

Sedative and hypnotics that alter higher cognitive function by depressing the CNS include Ethanol, Scopolamine, Quinnuclidinyl benzilate, Temazepam and various barbiturates, such as Sodium thiopental ( Commonly known as Sodium Pentothal), Sodium Amytal (Amobarbitol), Seconal are particularly worth mentioning. 

Scopolamine (an alkaloid of atropine group) was the first chemical substance is used, but now a days, the barbiturates, particularly the Sodium Pentothal is the drug of choice for the Narco-analysis. 

Procedure of Narco-Analysis Test

It includes – 

1. Pre Test Interview

2. Pre Narcotic State

3. Semi Narcotic State

4. Post Test Interview

Pre Test Interview – Individual is explained regarding the whole procedure and informed consent is taken. 

Pre Narcotic State – Anesthetic induces narco and maintain the pre narcotic state throughout the interview. Drug is injected till the person appears relaxed and in a state of good contact. 

Semi Narcotic State – After establishing the semi narcotic state and the individual appears to be –

a. Flushed

b. Slowing and Slurred speech

Forensic psychologist and psychiatrist facilitate the interview. 

  • Individual is allowed to sleep of and allowed to wake up. 
  • Once he/she wake up, anaesthetist checks him/her and allow to drink coffee or tea. 
  • Complete narco interview is audio – video recorded and also written. 

Post Test Interview – it includes- 

a. Memory is checked

b. Individual is allowed to know what he/she has spoken during interview. 

c. Individual experience more relax and anxiety free state. 

Narco-Analysis in India

A few democratic countries, India most notably, still continue to use Narco-analysis. 

Narco-analysis for the purpose of interview is conducted in a forensic laboratory. 

In India, at Bangalore and Gujarat test is conducted. 

Consent of Court is required. 

Few Cases where it has been aid

Veerappan Case

Godhra Carnage probe

Abdul Karim Telgi Case

Bhanvri Devi Case

Mumbai Train Blast

Malegaon Blast

Nithari Murder Case

Aarushi Murder Case

Shasi Murder Case

Abu Salem

Mohammad Ajmal Amir Kasab, a Lashkar-e-Taiba militant

Importance of Narco-Analysis

  • Narco-analysis involves the use of certain barbiturates, using Sodium Pentothal. 
  • It is used in conjunction with other tests – Polygraph or the Lie detector test, psychological profiling or Brain mapping. 
  • The most laborious part of a criminal investigation is extracting information from an uncooperative source and therefore, narco-analysis provides a simply, non – violent method of finding out the truth. 

Advantages & disadvantages of Narco Analysis in Indian criminal justice system:

After analysing the cases of higher courts in India, it can be said that even Indian judiciary is not very much clear while in few cases court has affirmative view on the process of narco analysis but in some other cases court denied and clearly said it can’t be permitted. In their judicial pronouncements the courts have given conditional utilization of process. It can be said that the judiciary took harmonious construction regarding the use of this process and given interpretation of conditional utilization so that the process absolutely could not be ignored nor it can be used in each and every cases of crime.


By looking the present pathetic condition of society regarding criminals, crime rate and affected innocent people, it seems to be right time to check the ways by which this can be reduced. It can be possible by giving rich technology to the investigation agencies and Narco analysis is one of them.

The questions framed by the specialized person and expertise of the process so there is very less possibility to tell a lie, as indicated by many foreign and Indian writers.

The evidence extracted through this process may be denied as reliable but it can be used to get an admissible evidence, to corroborate with other evidence or in support of other evidence.

Mere questioning of a person by a police officer while the person is suspected in a crime and the same is voluntary statement can’t reveal as incriminatory. As in Abu Salem Case, he disclosed many important information and his involvement of crime.


In the process the chemical is administered in the body of a person so the dose of the chemical decides according to physique, mental attitude and will power of the person. A wrong dose of chemical may lead to a state of coma or even death of the person.

If the person is drug addicted one then again the process is not as much successful as needed for collecting evidence.

Reliability of information given by the subject is also under some shadow because the subject from whom the information is collected is in semiconscious stage and hence the question of reliability of such information is being raised.

The well known principle of criminal justice system is that the person giving information should be “well and fit” but in the narco analysis test the person is in semiconscious stage.


It is not hundred percent accurate. It has been found that certain subject’s made totally false statements.

It has been found that a person has given false information even after administration of drug. 


It is proven technique in the medical setup as well as in forensic setup for investigation purpose. 

This test require procedure, precautions and expertise to use in the investigation. 

Narco analysis is admissible in Court as a co – evidence. 

Legal Status

Regarding the legal status of Narco-analysis, one needs to interpret carefully the Article 20(3) of the Indian Constitution and Section 161(2) of the Criminal Procedure Code, 1973.

On 5th may 2010 Supreme Court of India concluded following point on this test – 

Article 20 (3) of the Indian Constitution, 

“No person accused of any offence shall be compelled to be a witness against himself”.

The test result cannot be admitted as evidence, if they have been obtained through the use of compulsion. 


Ambedkar S. N., Barnwal Ajay.“Narco-analysis Test: An analysis of various judgements of Indian Judiciary”.IOSR Journal of Humanities And Social Science 19.10 (2014) :52-57

Khan Farooq Gowsia, “Narco-analysis test: A blessing to criminal justice system, it’s reliability and admissibility in light of various Judgements”. International Journal of Law 4.2 (2018) :311-317

“The Concept of Narco-Analysis in view of Constitutional Law and Human Right” by Sonakshi Verma