Narco Analysis

Narco Analysis Test or Narco Test: This refers to the practice of administering barbiturates or certain other chemical substances, most often Pentothal Sodium, to lower a subject's inhibitions, in the hope that the subject will more freely share information and feelings. The term Narco Analysis was coined by Horseley. Narco analysis first reached the mainstream in 1922, when Robert House, a Texas obstretrician used the drug scopolamine on two prisoners.Since then narco testing has become largely discredited in most democratic states, including the United States and Britain. There is a vast body of literature calling into question its ability to yield legal truth. Additionally, narcoanalysis has serious legal and ethical implications.

A person is able to lie by using his imagination. In the Narco Analysis Test, the subject's inhibitions are lowered by interfering with his nervous system at the molecular level. In this state, it becomes difficult though not impossible for him to lie .In such sleep-like state efforts are made to obtain "probative truth" about the crime. Experts inject a subject with hypnotics like Sodium Pentothal or Sodium Amytal under the controlled circumstances of the laboratory. The dose is dependent on the person's sex, age, health and physical condition. The subject which is put in a state of Hypnotism is not in a position to speak up on his own but can answer specific but simple questions after giving some suggestions. This type of test is not always admissible in the law courts. It states that subjects under a semi-conscious state do not have the mind set to properly answer any questions, while some other courts openly accept them as evidence. Studies have shown that it is possible to lie under narcoanalysis and its reliability as an investigative tool is questioned in most countries. A few democratic countries, India most notably, still continue to use narcoanalysis. This has come under increasing criticism from the public and the media in that country. Narcoanalysis is not openly permitted for investigative purposes in most developed and/or democratic countries.

In India, the Narco Analysis test is done by a team comprising of an anaesthesiologist, a psychiatrist, a clinical/ forensic psychologist, an audio-videographer, and supporting nursing staff.The forensic psychologist will prepare the report about the revelations, which will be accompanied by a compact disc of audio-video recordings. The strength of the revelations, if necessary, is further verified by subjecting the person to polygraph and brain mapping tests.

The test

Truth serum are drugs used in narco-analysis that cause a person to become uninhibited, but they do not guarantee the veracity of the subjectís statement. People who are under the influence of truth serums enter a hypnotic state and speak freely about anxieties or painful memories. The subjectís imagination is neutralised when semi-conscious, making it difficult for him/her to lie and his/her answers would be restricted to facts of which he/she is aware. However, there are cases that show that subjects can create fantasy and deception under the influence of these drugs. In India, the test is done but with the consent of the person in question. If a person refuses to go by this test, the investigating agency cannot force him.


Although inhibitions are generally reduced, people under the influence of truth serums are still able to lie and even tend to fantasise.

Drugs administered

Sodium pentothal is an ultrashort-acting barbiturate, which sedates only for a few minutes. It slows down the heart rate, lowers blood pressure, and inhibits brain and spinal cord activity. Sodium amytal and Scopolamine are other drugs used.

Legal position

Such tests generally donít have legal validity as confessions made by a semi-conscious person are not admissible in court. The court may, however, grant limited admissibility after considering the circumstances under which the test was obtained. In the main, these tests can only assist police investigations.

External links

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Narco Analysis, P300 tests: What are these?

Vijay Singh in Mumbai | February 11, 2004 08:32 IST

The submission of the report on the Narco Analysis and P300 tests by the Special Investigation Team probing the fake stamp paper scam has given rise to two questions:

1. What are these?
2. Are the reports admissible in court as evidence?

To answer the first question:

Narco Analysis Test:
A person is able to lie by using his imagination. In the Narco Analysis Test, the subject's imagination is neutralised by making him semi-conscious. In this state, it becomes difficult for him to lie and his answers would be restricted to facts he is already aware of.

Experts inject a subject with Sodium Pentothal or Sodium Amytal. The dose is dependent on the person's sex, age, health and physical condition. A wrong dose can result in 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 but simple questions. The answers are believed to be spontaneous as a semi-conscious person is unable to manipulate the answers.

P300 Test:
When the brain recognises a person or a sound, it generates a particular type of electric wave, which is called a P300.

Sensors are attached to the head of a person undergoing a P300 test and the subject is seated before a computer monitor. He is then shown certain images or made to hear certain sounds. The sensors monitor electrical activity in the brain and register P300 waves, which are generated only if the subject has some connection with the stimulus, in this case pictures or sounds.

The subject is not asked any question.

These test are used by investigators to cross check their findings, determine if a suspect is telling the truth or make him reveal facts pertaining to a case.

To answer the second question:

Lawyers are divided on whether the results of Narco Analysis and P300 tests are admissible as evidence in courts.

"Confessions made by a semi-conscious person is not admissible in court. A Narco Analysis Test report has some validity but is not totally admissible in court, which considers the circumstances under which it was obtained and assess its admissibility," advocate P R Vakil told He represents former Maharashtra deputy chief minister Chhagan Bhujbal's nephew Sameer's Bhujbal.

"Under certain circumstance, a person may hold a certain belief. By repeatedly thinking about an issue in a particular way, he begins to believe that what he is thinking is right. But it need not necessarily be the truth," Vakil explained.

"Results of such tests can be used to get admissible evidence, can be collaborated with other evidence or to support other evidence. But if the result of this test is not admitted in a court, it cannot be used to support any other evidence obtained the course of routine investigation."

Criminal lawyer Majeed Memon, who filed a PIL in the Telgi case on behalf of social activist Anna Hazare, said, "The court had given permission to conduct these tests. Only it can decide the admissibility of the test result and other related evidence. Such reports can be used as evidence or to support other evidence."

Another criminal lawyer Sham Keswani has a different view. "Such tests don't have any legal validity. They can only assist the police investigation. In the Telgi case, the court permitted the tests to help the probe.

But, in case a person is not affected by the chemical, he might take some wrong names (to mislead investigators). The results of such tests can be used to support other evidence," he said.


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