The Supreme Court ruling of May 5, 2010 on the use of narco-analysis, brain-mapping and polygraph tests in police investigations in India was a welcome verdict in a broader sense, but it was an incomplete exercise.

As the Chairman of the Law Commission of India, I examined the merits and demerits of the spurt over the last 10 years in the use of narco-analysis, brain-mapping and polygraph tests in India. I finalised the Commission's report ( The Hindu, May 7, 2009), and at the time of submitting it demitted office. The exercise was initiated after the Commission received a memorandum from the Forensic Science Society of India, represented by its founder-president, Professor P. Chandra Sekharan. The media, human rights organisations, academic and professional bodies such as the Forensic Science Society of India, the Indian Psychiatric Association, and the Indian Medical Ethics group were involved in the debates. The Commission discussed the validity of the techniques from the constitutional angle and also in scientific, ethical and human rights terms.

No doubt, the Supreme Court's ruling vindicated my personal opinion. It is also a timely move to curb the sudden revival and marketing by some Indian pseudo-scientists of the almost hundred years old narco and polygraph tests combined with the more recently introduced brain-mapping test as a ‘three-in-one package.' But the rider that the ruling would not apply to those voluntarily agreeing to undergo them is based more on the constitutional position than on the scientific perception and the ground reality.

Even from the constitutional angle, how can a wrong become a right when it is done with consent? The arguments brought forth by the Supreme Court against the forcible use of narco-analysis, polygraphy and brain fingerprinting should hold good when these are used with consent.

Nevertheless, the Supreme Court's decision is laudable. It undertook an elaborate exercise to understand the tests, their uses, limitations and precedents, citing decisions of U.S., Canadian and British courts in its 250-page judgment.

But, as far as narco-analysis is concerned, the court did not go into the details regarding at least six aspects concerning the ground realities. First, why was the age-old and abandoned narco-test suddenly revived in India only during the last 10 years, and that too by psychologists appointed as lie detector technicians in Forensic Science Laboratories? Secondly, why were non-medical psychologists permitted to perform narco-analysis, which is an invasive medical procedure that is conducted by medical psychiatrists all over the world when it was in vogue or practised until being abandoned?

Third, is there any evidence to show that the old narco-analysis technique has been improved to any degree by these psychologists through authoritative research, peer review and publications? Fourth, is there a scientific test to assess accurately whether an individual is awake or in trance (hypnotic stage) after the drug is administered? Fifth, why is narco-analysis offered as a confirmatory test in a ‘three-in-one package' of polygraph, brain fingerprinting and narco-analysis tests, conducted in that order, by one and the same psychologist? Sixth, when narco-analysis tests are carried out on the same subject five or six times until the desired answer is obtained, how can they be considered scientific?

The court has discussed narco-analysis techniques in 26 paragraphs, and all the citations indicate that the narco-analysis expert is a psychiatrist (medical personnel) and not the non-medical psychologist as is the case in India.

The judgment, while dealing with the brain fingerprinting technique in Paragraphs 67 to 77, refers to the technique as the “Brain Electrical Activation Profile (BEAP)” test, again guided by the ‘Laboratory Procedure Manual (2005)' and the ‘Brain Electrical Activation Profile' provided by the Directorate of Forensic Science, Ministry of Home Affairs, and the Government of India.

The observation that “there is an important difference between the ‘P300 waves test' used by the Forensic Science Laboratories in India and the ‘brain fingerprinting technique' is not vouchsafed with any citation.

The brain fingerprinting technique was developed and patented in 1995 by Lawrence A. Farwell of the U.S. His technique was so science-fictional that there were no takers in other parts of the world. In India, brain fingerprinting research is really a hoax: no peer-reviewed research paper has come out from an Indian research group.

The Indian group of psychologists that claimed to have developed its own brain fingerprinting techniques had its early moorings in the National Institute of Mental Health and Neuro Sciences (NIMHANS). But a committee chaired by the Vice Chancellor-Director of NIMHANS appointed by the Union Minister of Home Affairs to examine the scientific validity of the brain fingerprinting technique practised by the two Indian groups, declared both the techniques unscientific and recommended their discontinuance.

Both groups use the EEG (electroencephalograph) to detect scalp electrical signal output. The signal detected by the scalp electrode is pre-dominated by excitatory and inhibitory post-synaptic potentials on dendrites and neuronal cell bodies, not the deeper axon action potentials. EEG is compared to a listener sitting outside a football stadium and cannot see the activity inside, but may make some guesses about the course of the game based on hearing the roar of the crowd. This does not allow the listener to understand the details of the game or what may be transpiring between coach and player.

Similarly, a scalp electrode can detect the fluctuating tonic activity of millions of neurons allowing the electroencephalographer to make broad assumptions about brain functioning. However, this technique is not sensitive to the exquisite detail that is needed to appreciate neural activity associated with cognitive processes or mood states. While this is the correct and latest assessment of the EEG even in medical diagnosis, how can non-medical psychologists claim to read reactions of the brain to pinpoint a guilty person?

The Supreme Court has discussed the use of the polygraph test elaborately in a convincing manner. But I am sceptical of its direction that the ‘Guidelines for the Administration of Polygraph Test (Lie Detector Test) on an Accused' prescribed by the National Human Rights Commission in 2000 should be adhered to and that similar safeguards should be adopted to conduct narco-analysis and the brain electrical activation profile test. A non-medical technician can do a polygraph test. But only a psychiatrist, with the assistance of a medical team, can do narco-analysis.

The Supreme Court has used its long arm to silence the misinterpretation of the legal experts, claiming that the provision for ‘medical examination' under the Code of Criminal Procedure 1973 includes the narco-analysis technique, the polygraph examination and the BEAP test.

Forensic science never owned the polygraph, or the more recent science-fictional brain fingerprinting, as scientific tests belonging to its armoury. The polygraph test was the tool of the criminal investigator rather than the forensic scientist even before it fell into disrepute. Its functions have been handled the world over by people trained in the techniques of criminal investigation and interrogation and not by the forensic scientist.

Unlike expert witnesses who testify about matters outside the court's expertise, such as fingerprint analysis or ballistics, a polygraph expert can provide only an opinion. Since one cannot reliably measure human emotions, the idea of valid detection of truth or falsehood by measuring the respiratory rate, blood volume, pulse rate and galvanic skin response is pretence. Since psychologists cannot ascertain what emotions one has, polygraph professionals are not able to do that either.

“It is completely without any theoretical foundation and has absolutely no validity. Although there is disagreement amongst the scientists about the use of polygraph testing in criminal matters, there is almost universal agreement that polygraph screening is completely invalid and should be stopped”. I am yet to come across any peer-reviewed published research paper by an Indian group against this view.

In the opinion of the former Supreme Court Judge, Justice K.T. Thomas, narco-analysis is a crude technique in criminal investigation. He said the trial of a criminal case should not be one meant to convict the accused, but one meant to ensure that an innocent person was not convicted.

Had the Supreme Court examined the veracity of the impugned techniques from this angle, it would not have given room to the rider on the tests done with consent. A careful reading of the discussion, especially in Paragraphs 169, 170, 193, 194, 196, 217, 218, and 220 of the judgment in Criminal Appeal No.1267 of 2004 in Smt. Selvi and others vs. State of Karnataka, shows that it runs in favour of a total ban of the tests. How many people will know the real meaning of consent and its legal implications?

Those who will be affected by this rider will be common folk. It is for the Supreme Court to re-examine the issues and give a clear-cut verdict in the public interest.

(Dr. (Justice) A.R. Lakshmanan was Chairman of the 18th Law Commission of India and a Judge of the Supreme Court of India.)

The Supreme Court ruling on the use of narco-analysis and similar tests remains an incomplete exercise and deserves re-examination.