Supreme Court Issues Uniform DNA Evidence Guidelines

The Supreme Court of India has issued uniform guidelines to ensure proper handling of DNA samples in criminal investigations , addressing frequent lapses in collection, storage, and transport. The move aims to prevent contamination and delays in forensic analysis.

Why Guidelines Were Needed

In a recent case involving serious crimes, vaginal swab samples were delayed in reaching forensic labs, and the chain of custody was not maintained . Such lapses risked contamination, weakening the prosecution’s case. Recognising DNA’s critical role, the court stepped in to create a standard protocol for all states .

Key Directives by the Supreme Court

1. Proper Documentation – Every DNA sample must carry details like FIR number, statutes, and signatures of doctors, police, and witnesses.

2. Timely Transfer – Samples must be delivered to forensic labs within 48 hours ; delays must be explained in writing.

3. No Tampering – Once sealed, samples cannot be opened without court approval .

4. Chain of Custody Register – A record must be maintained from collection till trial and attached to court proceedings.

Judicial Observations

The court noted that DNA evidence is opinion evidence under the Indian Evidence Act and is credible only if scientific and procedural standards are strictly followed. Past cases have seen DNA results rejected due to mishandling.

Importance of DNA Evidence

DNA, extracted from blood, hair, saliva, or other biological material, is vital in linking suspects to crime scenes. However, it is not conclusive proof by itself and must be backed by proper collection, storage, and legal procedures.

Shared Responsibility

• Investigating officers must prevent contamination and ensure swift transfer.

• Forensic experts must maintain strict lab standards.
  Together, they safeguard the integrity of evidence for fair trial outcomes.