Explained: CBI wants to use polygraph tests on PNB scam accused; what is it?
Called the 'Lie Detector Tests', several instruments are used including cardiographs, sensitive electrodes and injections in the course of these examinations to put a person in a hypnotic state to 'reduce' their ability to lie or manipulate.
The Central Bureau of Investigation (CBI) has sought to conduct narco analysis and polygraph tests on a former staffer of the Punjab National Bank (PNB) to ascertain “his motives and details of undue pecuniary advantage obtained by him” in exchange of allegedly conniving with absconding diamantaires and his uncle, Mehul Choksi in the Rs 7,000-crore alleged fraud case.
On Wednesday, Gokulnath Shetty, the 63-year old retired deputy manager of PNB, for the test, stating among other reasons that it could have an adverse effect on his health. He also cited a Supreme Court judgment which mandates consent of the accused for performing any such tests.
What are narco analysis and polygraph tests?
Called the ‘Lie Detector Tests’, several instruments are used including cardiographs, sensitive electrodes and injections in the course of these examinations to put a person in a hypnotic state to ‘reduce’ their ability to lie or manipulate.
Investigating agencies claim that these tests are used for improving investigation efforts in criminal cases.
A ‘control-question’ technique is usually used, where after a question is asked, the response is measured through aspects like respiration, pulse and blood pressure to determine whether the person is stating the truth or lying.
What has Supreme Court said about lie detector tests?
In the case of Selvi & Ors vs State of Karnataka & Anr in 2010, the Supreme Court bench of Chief Justice K G Balakrishnan, R V Raveendran and J M Panchal, considered the “tensions between the desirability of efficient investigation and the preservation of individual liberties”.
The bench had concluded that compulsory administration of such techniques violated the right against self-incrimination, where no accused can be compelled to give evidence against himself.
The bench concluded that no lie detector tests should be administered except with the consent of the accused.
It also set further guidelines about the evidence value of the tests in a criminal trial, stating that it cannot be considered a “confessional” statement but considered to have the same status as a statement made before the police.