SUPREME COURT LAYS DOWN GUIDELINES FOR DNA EVIDENCE HANDLING, ACQUITS DEATH ROW CONVICT IN SENSATIONAL DOUBLE MURDER CASE

In a landmark judgment delivered on July 15, 2025, in Kattavellai @ Devakar v. State of Tamil Nadu (Criminal Appeal No. 1672 of 2019), the Supreme Court of India acquitted a man on death row, overturning his conviction for the murders and rape that had sent shockwaves across Tamil Nadu.

The Court’s detailed ruling not only exposed grave lapses in investigation, but also issued far-reaching directions for the collection, preservation and use of DNA evidence in criminal trials.

BACKGROUND OF THE CASE

On May 14, 2011, two young adults, Ezhilmuthalvan (“D1”) and Kasturi (“D2”), disappeared after visiting Suruli Falls. Days later, their decomposed bodies were discovered in a forest. The prosecution case largely rested on circumstantial evidence, primarily the testimony of a witness (PW-5), recovery of a gold chain, DNA results and the accused’s confessions.

Both the Trial Court and the Madras High Court convicted the accused, Kattavellai @ Devakar, imposing a death sentence, after holding that a chain of circumstantial evidence conclusively established his guilt.

SUPREME COURT’S FINDING

• Weaknesses in the Prosecution’s Case

The Supreme Court, speaking through Justice Sanjay Karol, conducted a searing analysis of each circumstance cited against the accused:

1. ‘Last-seen’ Theory: The principal witness (PW-5) claimed to have seen the accused threaten the deceased but did not report this until almost a week later. The Court found this conduct unnatural and the testimony unreliable, emphasizing that “mere possibility of differing human behaviour cannot override the reasonable man test.”
2. Confession and recovery: The accused’s confessions, recorded by police, were found to be unreliable, uncorroborated and inadmissible. The recovery of items like a sickle and personal articles failed to directly link the accused as none bore forensic proof or could be uniquely attributed to the victims.
3. DNA Evidence: The Court was especially critical of the chain of custody around DNA samples. Significant delays, unexplained gaps in storage, unclear transport procedures, and lack of consistent documentation fatally compromised the reliability of forensic results. The Court held that the sanctity of DNA evidence was irreparably breached and that such mishandling could not ground a conviction.
4. Test Identification Parade: The accused’s identity was already exposed to witnesses before formal identification, tainting the process. The Court reaffirmed that TIP is merely an investigative tool, not substantive evidence, and cannot be relied upon absent scrupulous adherence to procedure.
5. Motive and other lapses: The alleged robbery motive was undermined by the absence of key stolen items and unclear ownership of the recovered chain. Crucially, alternative suspects and a key eyewitness (Bhagyalakshmi) were not investigated or examined.

 

 

• Faulty investigation and Procedural Directions

The judgement laid down a bare a pattern of negligent investigative conduct, including but not limited to:

1. Evidence was collected and transported haphazardly;
2. Crucial witnesses were not examined;
3. The post-mortem was conducted at the crime scene, risking contamination;
4. There was a systematic failure to exclude alternative suspects.

In light of these findings and faults, the Hon’ble SC issued binding guidelines for the handling of DNA Evidence, which are as follows:

1.  Prompt and documented Collection: DNA samples must be collected swiftly, with all relevant case details and witnessed documentation.
2. Strict chain of Custody: Every movement of samples must be logged in a register appended to the trial record; delays and lapses must be explained.
3. Responsible Preservation: Packages cannot be opened or tampered with, without court order.
4. Training and Standardization: All states’ police must adopt uniform protocols and train officers accordingly.

 

 

• Acquittal and commentary on Wrongful Prosecution

Noting the absence of a proven chain of circumstances and accepting that the benefit of reasonable doubt must favor the accused, the Supreme Court set aside the conviction and ordered Devakar’s immediate release.

The bench also commented on the broader issue of wrongful prosecution and prolonged incarceration following eventual acquittal — referencing comparative international practices on compensation for wrongful detention.

KEY TAKEAWAYS FROM THE RULING OF THE HON’BLE SC

• DNA Evidence Requires Rigor: Lax procedures can render even the most advanced forensic tools unreliable.
• Benefit of Doubt Remains the Cornerstone: Convictions in cases resting on circumstantial evidence must exclude all reasonable alternatives.
• Systematic Reforms Mandated: The Court’s detailed orders on standardizing DNA evidence procedures aim to prevent future miscarriages of justice.
• Investigative Diligence Is Critical: Courts scrutinize every gap, delay, or omission in the fact-finding process, especially where life or liberty is at stake.

CONCLUSION

In the end, it can be concluded by stating that this judgement stands as a cautionary tale for law enforcement and prosecution. It reaffirms the Supreme Court’s commitment to procedural fairness, scientific integrity, and the constitutional presumption of innocence.

By crafting practical safeguards for the use of DNA evidence, the ruling aspires to restore public confidence and justice in complex criminal cases, ensuring that grave errors of the past are not repeated

 

Soumen Dash

Associate

The Indian Lawyer and Allied Services

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