The common understanding of DNA fingerprinting in India is that it is the final frontier in the medico-legal process. If there is DNA “evidence”, it is incontrovertible. This notion is misguided for a number of reasons. The first is the general ignorance of the constabulary and the judiciary on such matters. The second, is how poorly the interpretative, dynamic and sometimes inexact science of DNA fingerprinting is practiced in India. The key to practice, of course, is people. And the picture emerging in the Aarushi trial is that not only is the science of DNA fingerprinting as practiced in India flawed and without regard for international standards, the people involved are part of a system that has elevated corruption to a science, perhaps even to a philosophy.
S.P.R. Prasad, the canny scientist from the Centre for DNA fingerprinting and Diagnostics (CDFD) Hyderabad, whose long cross-examination continued through Tuesday in Ghaziabad, made up his own standards and procedures for DNA analysis before the trial court. In sum, the convoluted descriptions that Prasad gave to the court on how DNA analysis was conducted suggested that CDFD scientists worked, to put it charitably, in a manner that was innocent of prevailing practices the world over.
One of the basics of DNA fingerprinting is to avoid contamination in the laboratory testing the samples. Contamination could come from chemicals used or technicians handling exhibits, and controls are put in place to avoid this. None of the tests done in this case met these standards.
Forensics depends heavily on population databases to zero in on individuals at any scene of crime. In India, diverse and disparate as it is, practically no DNA databases of this nature exist, according to forensic scientist G.V. Rao, formerly of the CDFD.
The scientific process is one thing, but how about the clerical process? In this case, the life and liberty of the accused, Rajesh and Nupur Talwar, rest on a supposed typographical error. The report that Prasad originally signed incriminated Krishna, an employee of the Talwars. A neat swap of some code numbers after this fact was pointed out nullified this. The difficulty here is that Prasad was both the scientist and the typist. His cross-examination promises to be lengthy.
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