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Polygraph Test: Medical Examination of Accused

Selvi v. State of Karnataka
AIR 2010 SC 1974
Judges: K.G. Balakrishnan, R.V. Raveendran and J.M. Panchal, JJ.
Date of Decision: 5-5-2010
The legal questions in this batch of criminal appeals relate to the involuntary administration of certain scientific techniques, namely narcoanalysis, polygraph examination and the Brain Electrical Activation Profile (BEAP) test for the purpose of improving investigation efforts in criminal cases. This issue has received considerable attention since it involves tensions between the desirability of efficient investigation and the preservation of individual liberties. Ordinarily the judicial task is that of evaluating the rival contentions in order to arrive at a sound conclusion. However, the present case is not an ordinary dispute between private parties. It raises pertinent questions about the meaning and scope of fundamental rights which are available to all citizens. Therefore, we must examine the implications of permitting the use of the impugned techniques in a variety of settings.

Objections have been raised in respect of instances where individuals who are the accused, suspects or witnesses in an inves­tigation have been subjected to these tests without their consent. Such measures have been defended by citing the importance of extracting information which could help the investigating agencies to prevent criminal activities in the future as well as in circum­stances where it is difficult to gather evi­dence through ordinary means. In some of the impugned judgments, reliance has been placed on certain provisions of the Code of Criminal Procedure, 1973 and the In­dian Evidence Act, 1872 to refer back to the responsibilities placed on citizens to fully co-operate with investigation agen­cies. It has also been urged that adminis­tering these techniques does not cause any bodily harm and that the extracted infor­mation will be used only for strengthening investigation efforts and will not be admit­ted as evidence during the trial stage. The assertion is that improvements in fact-find­ing during the investigation stage will con­sequently help to increase the rate of pros­ecution as well as the rate of acquittal. Yet another line of reasoning is that these sci­entific techniques are a softer alternative to the regrettable and allegedly widespread use of ‘third degree methods’ by investigators.

The involuntary administration of the impugned techniques prompts questions about the protective scope of the ‘right against self-incrimination’ which finds place in article 20(3) of our Constitution. In one of the impugned judgments, it has been held that the information extracted through methods such as ‘polygraph exami­nation’ and the ‘Brain Electrical Activa­tion Profile (BEAP) test’ cannot be equated with ‘testimonial compulsion’ because the test subject is not required to give verbal answers, thereby falling outside the pro­tective scope of article 20(3). It was fur­ther ruled that the verbal revelations made during a narcoanalysis test do not attract the bar of article 20(3) since the inculpa­tory or exculpatory nature of these revela­tions is not known at the time of conduct­ing the test. To address these questions among others, it is necessary to inquire into the historical origins and rationale behind the ‘right against self-incrimination’ . The principal questions are whether this right extends to the investigation stage and the test results are of a ‘testimonial’ character, thereby attracting the protection of article 20(3).

Furthermore, we must examine whether relying on the test results or materials discovered with the help of the same creates a reasonable likelihood of incrimination for the test subject.

The scientific validity of the impugned techniques has been questioned and it is argued that their results are not entirely reliable. For instance, the narcoanalysis technique involves the intravenous administration of sodium pentothal, a drug which lowers inhibitions on part of the subject and induces the person to talk freely. However, empirical studies suggest that the drug-induced revelation need not necessarily be true. Polygraph examination and the BEAP test are methods which serve the respective purposes of lie-detection and gauging the subject’s familiarity with information related to the crime. These techniques are essentially confirmatory in nature, wherein inferences are drawn from the physiological responses of the subject. However, the reliability of these methods has been re­peatedly questioned in empirical studies. In the context of criminal cases, the reliability of scientific evidence bears a causal link with several dimensions of the right to a fair trial such as the requisite standard of proving guilt beyond reasonable doubt and the right of the accused to present a defence. We must be mindful of the fact that these requirements have long been recognised as components of ‘personal liberty’ under article 21 of the Constitution. Hence it will be instructive to gather some insights about the admissibility of scientific evidence.

Whether Polygraph Test to Accused amounts to seemingly disproportionate intrusion into personal liberty, their investigative use is justifiable.

Even though the main task of constitutional adjudication is to safeguard the core organising principles of our polity, we must also highlight some practical concerns that strengthen the case against the involuntary administration of the tests in question.

Firstly, the claim that the results obtained from these techniques will help in extraordinary situations is questionable. All of the tests in question are those which need to be patiently administered and the forensic psychologist or the examiner has to be very skilful and thorough while interpreting the results. In a narcoanalysis test the subject is likely to divulge a lot of irrelevant and incoherent information. The subject is as likely to divulge false information as he/she is likely to reveal useful facts. Sometimes the revelations may begin to make sense only when compared with the testimony of several other individuals or through the discovery of fresh materials. In a polygraph test, interpreting the results is a complex process that involves accounting for distortions such as ‘countermeasures’ used by the subject and weather conditions among others. In a BEAP test, there is always the possibility of the subject having had prior exposure to the ‘probes’ that are used as stimuli. All of this is a gradually unfolding process and it is not appropriate to argue that the test results will always prove to be crucial in times of exigency. It is evident that both the tasks of preparing for these tests and interpreting their results need considerable time and expertise.

Secondly, if we were to permit the forcible administration of these techniques, it could be the first step on a very slippery-slope as far as the standards of police behaviour are concerned. In some of the impugned judgments, it has been suggested that the promotion of these techniques could reduce the regrettably high incidence of ‘third degree methods’ that are being used by policemen all over the country. This is a circular line of reasoning since one form of improper behaviour is sought to be replaced by another. What this will result in is that investigators will increasingly seek reliance on the impugned techniques rather than engaging in a thorough investigation. The widespread use of ‘third-degree’ interrogation methods so as to speak is a separate problem and needs to be tackled through long-term solutions such as more emphasis on the protection of hu­man rights during police training, provid­ing adequate resources for investigators and stronger accountability measures when such abuses do take place.
Thirdly, the claim that the use of these techniques will only be sought in cases involving heinous offences rings hol­low since there will be no principled basis for restricting their use once the investiga­tors are given the discretion to do so. From the statistics presented before us as well as the charges filed against the parties in the impugned judgments, it is obvious that in­vestigators have sought reliance on the impugned tests to expedite investigations, unmindful of the nature of offences in­volved. In this regard, we do not have the authority to permit the qualified use of these techniques by way of enumerating the of­fences which warrant their use. By itself, permitting such qualified use would amount to a law-making function which is clearly outside the judicial domain.

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