Selvi and Ors. v State of Karnataka

• Investigating agencies in several cases subjected accused persons and suspects to polygraph, narco-analysis, and brain mapping tests without obtaining valid consent
• The validity of compelling such tests, and their use in criminal investigation and trial, was challenged as violative of Art.20(3) and Art.21

1. Whether the involuntary administration of polygraph, narco-analysis, or brain electrical activation profile tests on an accused or suspect violates Art.20(3) and Art.21 of the Constitution.

• Results from these techniques amount to testimonial compulsion, since they elicit responses from the subject's mind, and therefore fall within Art.20(3) protection
• If administered without free and informed consent, they also violate the right to privacy and mental integrity under Art.21
• These techniques can be administered only with the subject's voluntary consent, given after being informed of all implications, with a lawyer present and the process recorded
• Even with consent, results cannot by themselves be treated as confessions; they may only further investigation, subject to independently corroborated evidence at trial

Compelling a person to undergo polygraph, narco-analysis, or brain mapping tests without free and informed consent is unconstitutional, violating both the protection against self-incrimination under Art.20(3) and the right to personal liberty and mental privacy under Art.21; even consensual administration does not produce admissible confessions by itself.