Supreme Court Reinforces Chain-of-Custody & Expert-Witness Requirements for DNA Evidence

Comprehensive Commentary on Karandeep Sharma @ Razia @ Raju v. State of Uttarakhand (2025 INSC 444)

1. Introduction

The decision delivered on 4 March 2025 by a three-judge Bench (Vikram Nath, Sanjay Karol & Sandeep Mehta JJ.) marks a critical re-statement of procedural safeguards in criminal trials that rely on scientific evidence. The Court set aside a death sentence imposed on Karandeep Sharma for rape and murder of a minor, principally because:

• (a) the DNA evidence that underpinned the conviction was admitted without calling the scientific expert and without proving an unbroken chain of custody, and
• (b) the trial itself was vitiated by haste and absence of effective legal representation, offending the accused’s right to a fair trial.

This commentary dissects the judgment, the precedents cited, the legal reasoning adopted, and its likely influence on future jurisprudence.

2. Summary of the Judgment

1. The entire prosecution case rested on circumstantial evidence: “last-seen” testimony, the accused’s confession, alleged recoveries, and DNA/FSL reports.
2. The confession was rejected as involuntary; the “last-seen” witnesses were considered unreliable; the recoveries were held to be planted.
3. The Court held that DNA/FSL reports are inadmissible where:
   • the expert who performed the analysis is not examined, and
   • the prosecution fails to establish chain of custody & proper sealing of samples.
   It relied heavily on Rahul v. State of Delhi (2023) which demanded strict proof of reliability of forensic techniques.
4. Finding no legally admissible evidence, the Supreme Court acquitted the appellant and ordered his immediate release.

3. Detailed Analysis

3.1 Precedents Cited & Their Influence

• Rahul v. State of Delhi (2023) 1 SCC 83 – The Court reiterated that DNA profiling reports do not fall automatically under Section 293 CrPC; prosecution must prove the scientific process and reliability through expert testimony.
• Sections 24, 25, 26 Indian Evidence Act – Referred while discounting the police-recorded confession.
• Section 207, 173(2), 366 CrPC – Cited to underline procedural lapses in providing case materials and securing death-sentence confirmation.

While not overturning past authority, the Bench tightened the operational requirements extracted from these provisions, hence adding new depth to the procedural doctrine.

3.2 Legal Reasoning Employed

1. Right to Fair Trial: The Court catalogued the chronology—absence of counsel, overnight framing of charges, rushed recording of prosecution evidence—and held that these cumulatively violated natural justice.
2. Evidentiary Requirements for DNA Proof:
   • Non-examination of the scientist violates the accused’s right to cross-examine under Section 138 Evidence Act.
   • An unbroken & proven chain of custody is a sine qua non to avoid tampering concerns.
   • The Court placed the burden squarely on the prosecution to demonstrate “sanctity and self-same condition” of samples.
3. Assessment of “Last-Seen” Evidence:
   • Witnesses did not identify the accused in court.
   • No Test Identification Parade (TIP) was held.
   • Silence of witnesses during FIR stage raised suspicion.
4. Doctrine of Benefit of Doubt: With each link in the circumstantial chain broken, the conviction could not stand.

3.3 Impact & Prospective Significance

Potential ripple effects:

• Tightened Prosecution Standards: Investigating agencies must meticulously document seizure, sealing, storage, and transport of biological samples, and ensure expert attendance at trial.
• Enhanced Role for Trial Courts: Judges must proactively verify if Section 207 CrPC compliance and legal aid provisions have been honoured before framing charges, especially in capital cases.
• Defence Strategy: Defence counsel will more aggressively challenge forensic evidence on chain-of-custody grounds.
• Training & Infrastructure: Police, FSLs, and public prosecutors may need revised SOPs and capacity-building to meet the reinforced standards.
• Death Penalty Jurisprudence: Continues the trend of heightened scrutiny in capital cases, aligning with comparative constitutional jurisprudence that “death is different.”

4. Complex Concepts Simplified

• Chain of Custody: A chronological paper trail showing every person who handled the evidence from collection to courtroom. If broken, contamination or tampering cannot be ruled out.
• DNA Profiling: Laboratory technique comparing genetic markers in biological samples. Legally, it is “opinion evidence” under Section 45 Evidence Act and must be proved through the expert who conducted the test.
• Last-Seen Theory: A circumstantial presumption that a person last seen with a victim is responsible for the crime if no other explanation exists and the gap between sighting and discovery of crime is small.
• Test Identification Parade (TIP): Pre-trial process where witnesses identify a suspect from a line-up; ensures the in-court identification is not a product of suggestion.
• Section 293 CrPC: Allows certain scientific reports to be used as evidence without calling the author, but the Supreme Court clarifies that DNA reports fall outside its automatic ambit.

5. Conclusion

The Supreme Court’s ruling in Karandeep Sharma crystallises an emerging norm: scientific evidence is potent but only when procedural integrity is unimpeachable. By acquitting an accused facing the gallows, the Court signalled that investigative shortcuts and judicial haste are incompatible with constitutional guarantees, particularly in capital cases.

Going forward, the judgment will serve as a cautionary beacon to trial courts and investigating agencies. The principle that DNA reports are inadmissible absent expert testimony and a proven chain-of-custody is now affirmed at the highest level, filling a grey area left after Rahul. Equally, the decision underscores that legal aid and adequate preparation time are not formalities but fundamental to the legitimacy of criminal adjudication.

The message is unequivocal: science may illuminate the path to truth, but justice demands that the lamp itself be pristine.