Introduction
DNA (Deoxyribonucleic Acid) evidence has emerged as one of the most reliable tools in modern criminal investigations. By offering a unique biological signature for each individual (except identical twins), DNA evidence can link suspects to crime scenes, establish identity, and even exonerate the innocent. However, in India, inconsistencies in handling DNA evidence have often led to wrongful convictions or acquittals.
Recognising this, the Supreme Court recently issued uniform guidelines for the management of DNA evidence, aiming to bring credibility, fairness, and scientific rigour to the criminal justice system.
What is DNA Profiling?
●
Definition:
DNA profiling, also known as DNA fingerprinting, is the process of identifying
individuals by analysing unique genetic markers. While 99.9% of human DNA is
the same, the 0.1% variation (mainly Short Tandem Repeats or STRs) is used for
profiling.
●
Structure of
DNA: It is a double-helix molecule composed of nucleotides — Adenine (A),
Thymine (T), Guanine (G), and Cytosine (C) — organised into 23 pairs of
chromosomes inherited equally from both parents.
●
Sources: DNA
can be extracted from blood, semen, saliva, hair roots, skin cells, bones, or
even touch DNA. Degraded or low-quality samples may require techniques like
miniSTRs or mitochondrial DNA analysis.
●
Process: DNA
profiling involves isolation, purification, amplification of specific markers,
genotyping, and statistical analysis to compare profiles.
Why Did the Supreme
Court Intervene?
●
Inconsistent
Practices: Different states, police departments, and forensic labs followed
varying methods for collection and preservation, leading to discrepancies.
●
Risk of Wrongful
Convictions: Mishandling or contamination of evidence has, in several
cases, led to innocent people being implicated in crimes.
●
Judicial
Concerns: Courts often rejected DNA evidence when chain of custody was
unclear or when handling standards were poor, weakening trials and delaying
justice.
●
Need for Global
Standards: To align Indian practice with international norms and ensure
fairness, the Court mandated uniform procedures.
Key Guidelines of the
Supreme Court
●
Collection: Only
trained personnel should collect DNA samples, wearing protective gear to avoid
contamination. All evidence must be sealed in tamper-proof containers.
●
Labelling and
Documentation: Each sample must be labelled with FIR details, date, police
station, sections involved, and signed by the IO, a medical officer, and an
independent witness.
●
Transportation
and Storage: DNA evidence must be sent to forensic labs within 48 hours of
collection. Any delay must be recorded and justified.
●
Chain of
Custody: A detailed register should document every stage of handling — from
crime scene to courtroom — and must be appended to trial records.
●
Accountability:
The Investigating Officer is personally responsible for lapses or
non-compliance in handling DNA evidence.
Legal Provisions Governing DNA Evidence in India
●
Constitutional
Safeguards: Article 20(3) protects against self-incrimination, but courts
have held that DNA is physical evidence, not testimonial. Article 21 ensures
privacy and liberty, requiring safeguards in DNA use.
●
Criminal
Procedure: Section 53 and 53A of CrPC (now BNSS, 2023) permit collection of
biological samples for investigation, especially in cases of rape or violent
crimes.
●
Indian Evidence
Act: Sections 45–51 allow expert testimony, including DNA results, to be
admitted in courts.
●
Judicial
Precedents:
○
Sharda v.
Dharmpal (2003) – Courts can order DNA tests without violating Article 21.
○
Pattu Rajan v.
State of TN (2019) – DNA evidence is reliable but not infallible; must be
corroborated.
○
Das Anu v. State
of Kerala (2022) – DNA sampling does not violate Article 20(3).
●
Law Commission
(2017): Recommended a comprehensive DNA law, leading to the DNA Technology
(Use and Application) Regulation Bill, 2019, which is still pending.
Challenges in India
●
Limited
Infrastructure: Forensic labs face shortages of modern equipment, trained
experts, and adequate funding, making them unable to process rising DNA cases.
●
Backlog of
Cases: Delays in forensic results weaken investigations, as evidence may
degrade and cases drag on.
●
Training Gaps:
Many police officers, doctors, and lawyers lack specialised training in DNA
evidence handling, affecting reliability.
●
Privacy
Concerns: Without a legal framework, fears of misuse of DNA databases,
breaches of personal information, and surveillance remain high.
●
Legal
Misinterpretation: Courts sometimes overemphasise DNA matches, ignoring the
fact that DNA evidence must always be corroborated with other forms of proof.
Way Forward
●
Capacity
Building: Expand forensic labs, recruit experts, and invest in modern
equipment to improve efficiency.
●
Regular
Training: Continuous training of police, forensic experts, and judicial
officers in scientific collection and interpretation of DNA evidence.
●
Monitoring &
Compliance: Independent oversight to ensure guidelines are followed
strictly at every stage.
●
Legislation: Passing
the DNA Technology Bill with strong privacy protections is vital for a
comprehensive regulatory framework.
●
Balanced
Approach: Courts must treat DNA evidence as powerful but not conclusive,
always requiring corroboration for fair justice.
Conclusion
DNA evidence has transformed criminal investigations by offering objectivity and precision. Yet, its effectiveness depends on scientific handling, legal safeguards, and ethical responsibility. The Supreme Court’s guidelines mark a major step towards standardising DNA evidence management in India. However, challenges of infrastructure, privacy, and training remain. With proper reforms and a robust legal framework, DNA evidence can serve as a cornerstone of justice, ensuring fairness, accuracy, and protection of individual rights.