Putai v. State of Uttar Pradesh (2025): Supreme Court Reinforces the “Chain-of-Custody” Rule for DNA Evidence in Circumstantial Prosecutions

1. Introduction

In Putai v. State of Uttar Pradesh (2025 INSC 1042) the Supreme Court of India (bench of Vikram Nath, Sanjay Karol and Sandeep Mehta, JJ.) allowed the criminal appeals of two villagers, Putai and Dileep, who had been sentenced—one of them to death—for the rape and murder of a 12-year-old girl. The decision quashes the convictions on the ground that the prosecution’s circumstantial case was fatally tainted by an unproven and incomplete chain of custody for crucial DNA samples and other forensic exhibits.

The ruling creates a forceful precedent: where forensic science, especially DNA profiling, is relied upon in a case built solely on circumstantial evidence, the prosecution must establish an unimpeachable chain of custody and call the proper expert witnesses; failure to do so renders the scientific result inadmissible and insufficient for conviction.

2. Case Background

Date of crime: Evening of 4 September 2012 in Mohanlalganj, Lucknow district.
Victim: 12-year-old girl (referred to as “Mst. S.”).
Accused:
- Accused 1 – Putai: local cultivator and part-time factory worker.
- Accused 2 – Dileep: neighbour residing a short distance away.
Trial verdict (2014): A Sessions Judge convicted both under §§376(2)(g), 201 & 302 IPC; awarded death to Putai on the “rarest of rare” principle and life to Dileep.
High Court (2018): Confirmed convictions and death reference.
Supreme Court (2025): Allowed appeals; acquitted both for want of proof beyond reasonable doubt.

3. Summary of the Judgment

The Supreme Court examined the record de-novo, noting that the case rested entirely on circumstantial evidence—no eyewitness, no confession, no proven motive. Key incriminating links were:

Recovery of the victim’s chappals, water canister and allegedly her underwear from a field Tilled by Putai;
Recovery of a generic plastic comb allegedly belonging to Dileep, with dog-squad evidence tracing it to his house;
Two DNA reports—an inconclusive first report (2014) and a “supplementary” report (2014) surfacing during appeal, purportedly matching slides taken from the body with the accuseds’ blood samples.

The Court found every link unreliable. Crucially, the prosecution failed to prove when, how and by whom samples were drawn, sealed, stored, transported, received and tested. No maalkhana register, no forwarding letter, no receiver’s acknowledgment, no testimony from the carrier or the FSL custodian was produced. The expert who signed the supplementary report was never examined, and the report was not put to the accused under §313 CrPC. Consequently, both DNA reports were ruled inadmissible / worthless. Without credible forensic evidence, the remaining circumstances were held insufficient to reach the “must-be-proved” standard required by law. Benefit of doubt followed; convictions and death sentence were set aside.

4. Detailed Analysis

4.1 Precedents and Authorities Cited

Sharad Birdhichand Sarda v. State of Maharashtra (1984) 4 SCC 116 – five golden principles for circumstantial evidence reaffirmed; prosecution must exclude every hypothesis except guilt.
Raja v. State of Karnataka (2016) 10 SCC 506 – chain-of-custody requirement for DNA samples; conviction set aside where link missing.
Narender Singh v. State of Punjab (2022) 2 SCC 341 – importance of examining carrier witnesses and proving seal integrity.
State of Rajasthan v. Daud Khan (2016) 2 SCC 607 – dog-squad evidence is only corroborative; cannot be sole foundation of conviction.
Sections 106 Evidence Act, 293 CrPC – on shifting burden for facts especially within accused’s knowledge; on proof of expert reports.

The Court drew heavily on these decisions to articulate that scientific evidence is only as credible as the process that safeguards it; any break renders the result void of probative value.

4.2 Legal Reasoning

Breakdown of Chain of Custody
• Absence of arrest memos; no documents showing date/time of blood sample collection.
• No proof of sealing of vaginal swabs or slides; conflicting testimony on number of slides.
• Maalkhana register, dispatch memo, FSL receipt all missing.
• Ergo, possibility of tampering or contamination could not be excluded.
Inadmissibility of the Supplementary DNA Report
• Not proved by its author; introduced via an affidavit filed three years later.
• Not put to the accused for response – violates natural justice and §313 CrPC.
• “Two mutually destructive expert opinions” with no reconciliation ⇒ zero evidentiary value.
Dog-squad & Comb Recovery
• Colour of comb described differently by witnesses; ordinary generic article.
• No contemporaneous record of dog-squad exercise; hence unsafe to rely.
Conduct Evidence
• Alleged “suspicious” washing of hands/face by Putai deemed perfectly natural; could not be elevated to incriminating circumstance.
Prosecution’s Omission to Examine Vital Witnesses
• Tenancy/ownership of adjacent fields, factory co-workers, villagers on brick lane, etc., were never called.
• This lacuna raised doubt under the best-evidence rule.
Standard of Proof in Circumstantial Cases
• Court reiterated the “distance between ‘may be’ and ‘must be’” test; suspicion, however strong, cannot substitute proof.

4.3 Impact of the Judgment

The decision has far-reaching implications:

Heightened Forensic Protocol Scrutiny: Trial courts expected to demand strict documentary and oral proof for every hand-over of forensic material.
Supplementary Reports: Any additional scientific opinion filed after the original report must be proved by summoning the expert and providing the accused opportunity to respond; else it is void.
Limitation on Dog-Squad Evidence: Reaffirms that such evidence can at best be corroborative and must be duly documented.
Practical Effect on Investigations: Police and FSLs country-wide will likely issue revised SOPs emphasising seal integrity, contemporaneous documentation, and witness examination of carriers.
Future Litigation: Defence counsel in ongoing and future cases will rely on this precedent to challenge forensic evidence where the chain is incomplete.

5. Complex Concepts Simplified

Chain of Custody: The documented and witnessed journey of an exhibit from the moment it is collected to its production in court. Think of it as a relay race baton; if any runner (custodian) is un-identified or the baton is dropped (seal broken), the entire race is disqualified.
DNA Profile / Allele: A coded sequence unique to each individual (except identical twins) extracted from biological material. “Male specific allele” indicates the presence of Y-chromosome markers, confirming the biological material is of male origin.
Section 106 Evidence Act: When a fact is especially within the knowledge of one party, the onus may shift to that party to explain it. However, this does not relieve prosecution of its primary burden of proof.
Section 293 CrPC: Allows certain scientific reports to be admitted without calling the expert, but the court may—and generally should—summon the expert whenever the opinion is disputed or complex.

6. Conclusion

Putai v. State of Uttar Pradesh powerfully underscores that modern forensic science is a double-edged sword: it can clinch cases, but only if every procedural safeguard is honoured. By setting aside a capital conviction for want of a proven chain of custody and proper expert testimony, the Supreme Court sends a clear message to investigators, prosecutors and trial courts:

“Science does not abdicate the law’s insistence on reliability. The efficacy of DNA evidence rests not merely in laboratory accuracy but in the integrity of its journey from crime-scene to courtroom.”

The decision will likely recalibrate investigative practices across India, ensuring that in the zeal to secure convictions, constitutional guarantees of fair trial and due process are not sacrificed. More broadly, the judgment fortifies the jurisprudential bedrock that no person shall be deprived of life or liberty except by due process of law — a process that demands proof beyond reasonable doubt, even (and especially) in the most heinous of crimes.