Ravi Vs State Of Maharashtra: Use And Reliability Of DNA Analysis Using YSTR Method That Isolates Only The Male DNA By Comparing The Y-Chromosome

DATE OF JUDGEMENT:
3rd October, 2019

JUDGES:
Justices Rohinton Fali Nariman, R. Subhash Reddy, Surya Kant

PARTIES:
Ravi (Appellant)
State of Maharashtra (Respondent)

SUBJECT

The Supreme Court dealt with the reliability of Y-STR test in sexual assault cases and held that this test can be used as exculpatory evidence and is relied upon in several jurisdictions.

OVERVIEW

1. The appellant was found guilty under Sections 302, 363, 376 and 377 of the Indian Penal Code and was sentenced to death by the Trial Court. The decision of the Trial Court was upheld by the High Court and the appellant preferred an appeal before the Supreme Court.
2. The appellant contended that accused's house was in a crowded place and it was improbable that he could have taken the victim away without anyone noticing.
3. Furthermore, the appellants contended that there was no evidence regarding who collected the appellant's blood for DNA test and how it was preserved.
4. The appellants also questioned the validity of Y-Chromosome Short Tandem Repeat Polymorphism (Y-STR). The appellants contended that this test does not allow for individual identification in the same male lineage.

IMPORTANT PROVISIONS

Indian Penal Code:

• Section 302: Punishment for murder.—Whoever commits murder shall be punished with death orimprisonment for life, and shall also be liable to fine.
• Section 363: Punishment for kidnapping.—Whoever kidnaps any person from 1[India] or from lawfulguardianship, shall be punished with imprisonment of either description for a term which may extend toseven years, and shall also be liable to fine.

ISSUES

• Whether Y-STR can be relied upon as evidence in sexual assault cases?

ANALYSIS

1. The Court observed that under Section 106 of the Indian Evidence Act, the burden to prove that the appellant has not caused the injuries to the victim was on the accused and he has failed to do so. The Court observed that the victim was in the unlawful custody of the appellant till she died.
2. Furthermore, the forensic agencies were qualified and they testified that the tests were conducted in accordance with the guidelines issued by the Director of Forensic Science, Ministry of Home Affairs, New Delhi.
3. The Court held that the global medical literature supported the reliability of the Y-Chromosome Short Tandem Repeat Polymorphism (Y-STR) and in cases such as the instant one, traditional methods such as autosomal- STR are not possible.
4. The (Y-STR) provides for the isolation of only male DNA by comparing Y chromosomes. The Court held that this test can be relied upon as exculpatory evidence and is useful for corroboration in sexual assault cases.
5. The Court, thus dismissed the appeal and affirmed the death sentence.

CONCLUSION

The Supreme Court has rightly held that the Y-STR can be considered to be a reliable test. Where medical science has established the reliability of a test, the accused cannot be given the right to question its effectiveness. The Court has rightly observed that even if it does not differentiate between the males of the same lineage, it still can be relied upon as circumstantial evidence.

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