Doctors from the All India Institute of Medical Sciences (AIIMS) who performed the autopsy on Sunanda Pushkar have co-authored an article published in the Indian Police Journal’s latest issue, explaining how laboratory tests on viscera samples often fail to detect poison in cases of death due to poisoning. The journal is published by the Bureau of Police Research and Development under the Ministry of Home Affairs.
The doctors analysed about 50 reports submitted to AIIMS on suspected poisoning cases. “Generally, the viscera reports were found positive only for ethyl alcohol, methyl alcohol, phosphides, zinc phosphide and aluminium phosphide,” the authors observed.
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“In many cases, the viscera report is negative or detects the poison in the quantity not sufficient to cause death. This puts the autopsy surgeon in a fix as police expect him to give the cause of death so as to reach a logical ending to the probe,” the article stated.
The authors of the article include the three doctors on the medical board that performed the autopsy on Pushkar. They are Dr Sudhir Gupta, head of the forensic department at AIIMS, Dr Adarsh Kumar, member-secretary of the board, and senior resident Dr Shashank Poonia.
The article noted that in cases where “there is suspicion of foul play” – generally in cases of murder, dowry deaths, rash and negligent acts and abetment to suicide – “when the autopsy surgeon terms the death as unnatural and due to poisoning despite a negative viscera report, his opinion is frequently challenged by the aggrieved/accused party”.
Quoting cases from 1986 to 2005 where various courts in the country made observations on such cases, the study notes that “failure to find poison in viscera of the individual whose death is due to poisoning is a routine problem in India”.
The authors noted that residual analysis of poisons in Indian labs “is limited to 10-15 poisons commonly available in the area. The other major killer poisons/chemicals like insulin, KCl, Adrenaline can’t be detected in viscera”.
The authors said investigating officers “must have a very clear concept that merely a negative viscera report does not rule out death due to poisoning”.
The authors mention radioactive poisons like Thalium and Polonium, which are “difficult to detect by the Forensic Science Laboratory”. The board’s opinion sent to police in the Pushkar case also included these radioactive poisons classed under as “difficult to confirm”.