Decoding The Brain: A Legal and Ethical Inquiry into Neuro-Scientific Evidence in Indian Criminal Trials

Abstract: The rapid advancement of neuroscience has introduced controversial investigative techniques such as polygraph tests, narco-analysis, and brain electrical oscillation signature (BEOS) profiling into the Indian criminal justice system. These methods, often presented as scientific tools for unveiling concealed truths and enhancing the efficiency of criminal investigations, have sparked profound legal, constitutional, and ethical debate. While their use is often justified on grounds of public interest and technological progress, the reliability and constitutional validity of these measures remain deeply contested. This research paper critically examines the admissibility, evidentiary reliability, and ethical legitimacy of neuroscientific evidence in Indian criminal trials. It focuses particularly on the constitutional guarantee against self-incrimination under Article 20(3) of the Indian Constitution. Employing doctrinal analysis and case study methodology, the paper analyses key statutory provisions and landmark judicial pronouncements, especially Selvi v. State of Karnataka, which marked a significant turning point in judicial understanding of involuntary scientific techniques. The study evaluates whether these methods genuinely contribute to truth-seeking or function as coercive tools disguised in scientific objectivity. Further, the paper explores fundamental concerns surrounding bodily autonomy, mental privacy, and the scope for custodial abuse in the application of such techniques. It critically assesses the scientific foundation, accuracy, and procedural safeguards of these methods while drawing comparisons with international legal and ethical frameworks from jurisdictions such as the United States, United Kingdom, and the European Union. These comparisons help to identify best practices and highlight the gaps in India’s current regulatory landscape. The study concludes that while forensic neuroscience holds potential to assist justice delivery, it must operate within the boundaries of constitutional morality, human dignity, and evidentiary fairness. Without robust regulatory mechanisms, independent oversight, and strict adherence to ethical standards, the use of such evidence risks undermining due process and compromising fundamental rights. The paper advocates for a principled and rights-based framework that harmonises scientific innovation with the core tenets of Indian constitutional law, ensuring that justice is pursued not only efficiently but also lawfully and humanely.