Judicial Standards for Scientific Evidence - DNA
How DNA evidence was rejected by Supreme Court based on qualifications of the forensic expert
The role of DNA evidence in the acquittal several critical factors that questioned the reliability and authenticity of the DNA evidence presented by the prosecution. The Supreme Court of India, in its judgment, highlighted the inconsistencies and issues related to the DNA evidence which led to the acquittal of the accused-appellants. Here’s a step-by-step explanation of how DNA evidence played a role in their acquittal:
The judgment scrutinized the DNA evidence presented, revealing inconsistencies that questioned its reliability. The court noted discrepancies between the presence of DNA in various forensic samples, suggesting possible tampering. Moreover, the qualifications of the forensic expert, whose credentials did not align with human DNA profiling, further undermined the scientific evidence's credibility.
1. Inconsistencies in DNA Evidence:
The prosecution alleged that the DNA profile of Akhtar Ali matched the forensic samples taken from the victim, specifically the cervical swab. However, the presence of semen was reported in the cervical swab but absent in the cervical smear, vaginal swab, and vaginal wash, which raised significant doubts about the integrity of the forensic sampling process. This inconsistency suggested possible tampering or planting of evidence.
2. Chain of Custody Issues:
The judgment points out lapses in maintaining the chain of custody for the forensic samples. There was no documented record of where the samples were stored between the time of collection and their analysis, leading to concerns about the possibility of tampering with the samples.
3. Dubious Arrest and Sample Collection:
The manner in which Akhtar Ali was arrested was surrounded by doubts, as the prosecution failed to provide a clear and credible account of the arrest and the subsequent collection of DNA samples. This included the lack of authorization for his arrest and the absence of local witnesses to corroborate the arrest procedure, which further cast doubt on the reliability of the DNA evidence.
4. Expert Qualifications:
The qualifications of Dr. Manoj Kumar Agarwal, who conducted the DNA examination, were questioned. His background in Botany, rather than forensic science or human DNA profiling, raised doubts about his expertise in conducting DNA profiling, further undermining the reliability of the DNA evidence.
5. Failure to Establish a Complete Chain of Circumstances:
The Supreme Court emphasized that for a conviction based solely on circumstantial evidence, including DNA evidence, every link in the chain of circumstances must be conclusively established. In this case, the prosecution failed to provide an unbroken and reliable chain of evidence that could conclusively point to the guilt of the accused.
6. Lack of Motive and Last Seen Theory:
The prosecution's case relied heavily on circumstantial evidence such as motive and the last seen theory, both of which were inadequately substantiated. The absence of a clear motive and the unreliable 'last seen' testimony further weakened the prosecution's case.
7. Judicial Standards for Scientific Evidence:
The judgment underscored the importance of adhering to the highest standards of proof, especially when relying on scientific evidence like DNA profiling. Any inconsistencies or doubts regarding the scientific evidence must weigh against a conviction, particularly in cases involving severe penalties such as the death penalty.
In conclusion, the Supreme Court found the DNA evidence presented by the prosecution to be unreliable due to inconsistencies, questionable chain of custody, dubious arrest procedures, and the qualifications of the forensic expert. These factors collectively contributed to the acquittal of Akhtar Ali and Prem Pal Verma, as they undermined the credibility of the prosecution's case and failed to establish guilt beyond reasonable doubt.
