In the landmark case Selvi
v. State of Karnataka (2010), the Supreme Court examined the admissibility of scientific investigative procedures and the rights of arrested persons during investigation. Though primarily addressing forensic evidence, the Court established principles relevant to investigation procedures. Which principle was established?

In Selvi v. State of Karnataka (2010), the Supreme Court held that scientific investigative procedures like polygraph testing, narco-analysis, and brain-mapping require explicit, informed consent of the person undergoing the test. The Court emphasized that such procedures engage the person's right against self-incrimination and bodily integrity. Importantly, results cannot be used as direct evidence; they serve only as investigative aids. This principle protects arrested persons from invasive investigative procedures and aligns with BNSS provisions on medical examination (Sections 52-53), which require medical practitioners and impose dignity safeguards. The landmark judgment ensures that modern investigative techniques do not override fundamental constitutional protections afforded to arrested persons.