New Delhi: The Central Bureau of Investigation (CBI) probing the Kolkata doctor rape and murder case will on Friday put Sandip Ghosh, the former principal of RG Kar medical college and Hospital, through a polygraph test or popularly known as the lie detector test.
The lie detector test according to CBI is necessary because Sandip Ghosh is not cooperating with the CBI and not divulging information about the doctor’s rape and murder case.
Polygraph, narco-analysis and brain mapping tests have been red-flagged by the Supreme Court
But polygraph, narco-analysis and brain mapping tests or tools of scientific evidence gathering have been red-flagged by the Supreme Court of India to be violative of person’s privacy, bodily integrity and most importantly against the fundamental constitutional principle of right against self incrimination. As these tests involve tensions between the desirability of efficient investigation and the preservation of individual liberties.
Room was left by the apex court for voluntary administration of tests provided certain safeguards were in place
In 2010, the Supreme Court of India in the Selvi and others versus State of Karnataka judgment has categorically stated such tests cannot be forcibly administered. But room was left for voluntary administration of the tests provided certain safeguards were in place. Also, the court said that information collected though the polygrah test “cannot be admitted as evidence because the subject does not exercise conscious control over the responses during the administration of the test. However, any information or material that is subsequently discovered with the help of voluntary administered test results can be admitted as evidence.”
So, anything that is is disclosed by the former principal during the lie detector test will not be considered as evidence, but following the disclosure or statement made during the lie detector test, the CBI is able to uncover or collect further material in the case, it will be treated as evidence.
The court further said, “placing reliance on the results gathered from these techniques comes into conflict with the ‘right to fair trial’. Invocations of a compelling public interest cannot justify the dilution of constitutional rights such as the ‘right against self-incrimination’.”
Polygraph test also has several limitations and there is a margin for errors
Besides, the polygraph test also has several limitations and there is a margin for errors. The test relies on measured changes in physiological responses and may not necessarily be triggered by lying or deception but could also be triggered by nervousness, anxiety, fear, confusion or other emotions.
Article 20 (3) of the constitution ensures that no person accused of an offense shall be compelled to be a witness against themselves. This means that an individual cannot be forced to provide evidence or testimony that may incriminate themselves. It is a fundamental right that protects individuals from being compelled to be witnesses in their own criminal prosecution.
Desirability of invasive scientific test
But in recent times administering these techniques have come in handy as it improves and expediates the fact-finding process during the investigation stage and consequently helps to increase the rate of prosecution as well as the rate of acquittal.
One section of legal thinkers also believe that these scientific techniques are a softer alternative to the widespread use of ‘third degree methods’ by investigators.
Lie detector test
CBI has been know to rely on a control-question (CQ) technique in the lie detection test. Here, the person is asked to answer control questions and relevant questions. The control questions are irrelevant to the facts being investigated but they are intended to provoke distinct physiological responses, as well as false denials.
Responses to control questions are compared with the responses triggered by the relevant questions. Theoretically, a truthful subject will show greater physiological responses to the control questions which he/she has reluctantly answered falsely, than to the relevant questions, which the subject can easily answer truthfully.
