The Supreme Court of India, in a significant judgment delivered in early July 2025, laid down comprehensive guidelines governing the collection, preservation, and presentation of DNA evidence in criminal proceedings. A three-judge Bench comprising Justice Vikram Nath, Justice Sanjay Karol, and Justice Sandeep Mehta further called upon Parliament to enact legislation establishing a compensation framework for persons wrongfully convicted on the basis of flawed forensic evidence.
Background
The matter arose from a criminal appeal in which the accused challenged a conviction partly resting on DNA evidence that had been improperly collected and stored. The case brought into focus longstanding concerns over the absence of standardised protocols for forensic evidence handling in Indian criminal trials. While the Bharatiya Nagarik Suraksha Sanhita, 2023 (BNSS) introduced provisions relating to forensic investigation under Section 349, no uniform national guidelines existed for DNA evidence specifically.
Several wrongful conviction cases in recent years had exposed gaps in how forensic laboratories process biological samples, with contamination and chain-of-custody failures leading to unreliable results being admitted at trial.
Key Holdings
The Supreme Court issued the following directives:
Standardised collection protocols: All investigating agencies must follow uniform chain-of-custody procedures for biological samples, including tamper-evident packaging, continuous temperature monitoring, and documented handover at each stage.
Laboratory accreditation mandatory: DNA evidence shall be admissible only if processed by a laboratory accredited by the National Accreditation Board for Testing and Calibration Laboratories (NABL) or an equivalent body recognised by the Central Government.
Defence access to samples: Accused persons must be permitted to seek independent testing of biological samples at a laboratory of their choice, provided the sample quantity permits division without compromising its integrity.
Expert qualification standards: Courts must verify the qualifications and experience of forensic experts before admitting their testimony, with minimum competency benchmarks to be prescribed by the National Forensic Sciences University.
Compensation for wrongful conviction: The Bench observed that India lacks a legislative mechanism to compensate persons wrongfully convicted due to flawed forensic evidence. It recommended that Parliament consider enacting a dedicated statute providing for compensation, rehabilitation, and expungement of criminal records for such persons.
Implications for Practitioners
This judgment introduces a significant shift in how forensic evidence is scrutinised in Indian criminal trials. Defence counsel now have a clearly articulated framework to challenge DNA evidence at the threshold stage of admissibility, rather than merely contesting its weight during cross-examination. The requirement of NABL accreditation will likely render evidence from several state forensic laboratories inadmissible until they secure the requisite certification.
The right to independent testing represents a meaningful procedural safeguard, though its practical utility will depend on whether investigating agencies preserve adequate sample quantities. Practitioners should ensure that requests for sample division are made at the earliest opportunity, ideally at the stage of charge.
The call for wrongful conviction legislation, while not a binding direction, adds judicial weight to a reform that criminal justice advocates have long sought. Until Parliament acts, courts may rely on Article 21 and the Supreme Court's compensatory jurisdiction under Article 142 to grant relief in individual cases.