Case Comment: Beyond the Truth Serum: Consent, Mental Privacy, and the Limits of Narcoanalysis in Selvi v State of Karnataka

An investigation depends on obtaining information, but the State cannot use every available method to obtain it. This tension was at the centre of Selvi v State of Karnataka, 1 where the Supreme Court considered whether a person could be compelled to undergo narcoanalysis, a polygraph examination or a Brain Electrical Activation Profile (BEAP) test during a criminal investigation. These techniques were presented as useful ways to uncover facts when ordinary investigation proved difficult. The Court, however, had to decide what their use would mean for the right against self-incrimination and personal liberty.