In a piecepublished in the Deccan Chronicle in February 2016, KN Bhat, the former additional solicitor general of India, writes: “In criminal cases when police resort to lie-detector tests it should be concluded that the investigation has reached a dead-end and other methods of discovering evidence or eliciting information, including procuring a confession, have failed.”
The debate over the use of the lie-detector test has been ongoing in India for a long time. Like Bhat, several legal and scientific experts have long argued against its accuracy and high rates of error. Further, rights-based activists and organisations have previously opposed the test on humanitarian grounds, stating that it violates the fundamental rights of the person being subjected to it.
In India, the issue came before the Supreme Court in the case of Selvi vs State of Karnataka. In 2010, the court delivered a detailed judgment, in which it tested lie-detection techniques on two primary grounds. The first was whether the use of the tests could violate Article 20 (3) of the constitution, which states that no person accused of an offence shall be compelled to be a witness against herself. The second was whether the administering of such tests without the explicit consent of the person accused constituted a direct violation of Article 21—the right to life and personal liberty. The court ultimately forbade investigative agencies from making the test compulsory. “The use of narco-analysis, brain-mapping and polygraph tests”—the three commonly used types of lie-detection tests—“on accused, suspects and witnesses without their consent is unconstitutional and a violation of the ‘right to privacy,’” the court noted. It also noted that little empirical evidence is present to bolster the argument that the tests provide reliable leads for investigators.