_page-0001.jpg)
What's the article about?
- It talks about the issues surrounding accepting DNA reports as evidence by the judiciary.
Relevance:
- GS2: Government Policies; Functioning of the Judiciary;
- GS3: Science and Technology- Developments and their Applications and Effects in Everyday Life;
- Prelims
Context:
- In various cases, the HCs and the SC have refuted the findings of the DNA report as credible evidence to consider the accused as guilty.
- In this article, the writer talks about key points surrounding this issue.
What is DNA testing?
- DNA is a very powerful tool for investigation because no two people can have the same DNA except in the case of identical twins.
- DNA/Genetic tests are performed on a sample of blood, hair, skin, amniotic fluid (the fluid that surrounds a foetus during pregnancy), or other tissue.
Why does the judiciary question the credibility of DNA reports as valid evidence? - The collection of the sample for the DNA testing and the technique used for testing are two bases on which the judiciary questions the credibility of DNA reports as valid evidence.
- In the various cases, the Court held that there was the likelihood of contamination to the sample.
Analysis:
- Careful sampling is necessary:
- The first responder on the scene of crime needs to ensure that the DNA sample is taken carefully.
- There are multiple stages involved starting from collecting the right amount of sample in a proper way, then its storage and transfer to the appropriate lab facility.
- In the lab, care needs to be taken while performing tests on the collected sample.
- Any minor mistake during all these stages can greatly influence the result of DNA testing.
- Therefore, if the sample size and quality is good enough to reach a ‘match’ result, it cannot be said that the sample might be contaminated (irrespective of the fact that it was collected from an open area). Had the sample been sufficiently contaminated, the ‘match’ result would not have been arrived at.
- All stakeholders of the criminal justice system need to be sensitised about the techniques of DNA analysis.
- Issue of Random match probability:
- The Court has questioned the forensic expert for not mentioning the ‘random occurrence ratio’.
- This statistical ratio or ‘random match probability’ (RMP) is referred to as the frequency of the particular DNA profile in a population.
- A small RMP value means the profile is rare in the population and vice versa.
- The Central FSL, Directorate of Forensic Sciences, released a Working Procedures Manual Forensic DNA Testing in 2019, which prescribes the procedure for calculating RMP for automated STRs.
- Therefore, there is no justifiable reason for a DNA expert not to mention RMP in its report.
Way Forward:
- DNA technology has evolved over the years. As the evidence of DNA matching in criminal cases, particularly those based on circumstantial evidence, acquires great importance, some standard guidelines need to be laid down by the Court for admitting the DNA expert’s report as credible evidence.
