Why in news?
In September 2025 the Supreme Court laid down guidelines for the collection, preservation and presentation of DNA samples in criminal cases while deciding the case of Kattavellai @ Devakar v. State of Tamil Nadu. The Court aimed to ensure uniform procedures across the country and maintain the integrity of forensic evidence.
What are the guidelines?
- Proper documentation: Each sample must be packaged with details of the FIR, relevant sections of law, names of the investigating officer and medical officer, and signatures of independent witnesses. This ensures traceability from collection to court.
- Timely dispatch: DNA samples must be sent to a forensic science laboratory within 48 hours of collection. Any delay requires a written explanation, and samples must be refrigerated or preserved appropriately in transit.
- No tampering: Once sealed, the package cannot be opened or resealed without a trial court’s permission. This prevents contamination and questions over admissibility.
- Chain of custody register: A dedicated register must record every transfer of the sample, from collection through analysis to court submission, signed by all handlers.
Why are they important?
- Reliability: DNA evidence can strongly link a suspect to a crime scene, but it is sensitive to contamination. Strict procedures ensure scientific reliability and prevent wrongful convictions.
- Uniformity: Policing is a state subject in India. Uniform guidelines promote consistency across states, reducing discrepancies in collection and handling.
- Legal clarity: Past cases have seen DNA evidence rejected due to improper handling or prolonged storage (e.g., Rahul v. Delhi, 2022). Clear rules reduce litigation and help courts evaluate evidence confidently.
Way forward
States must disseminate the guidelines widely and train police officers, doctors and forensic personnel. Upgrading forensic laboratories, adopting digital tracking of samples and providing adequate funding will be crucial. Ensuring privacy and consent in the collection of genetic material will also be important in the future.