Negative viscera report and its medicolegal aspects

The obscurity of failure to find poison in viscera of the individual whose death is due to poisoning is a routine problem in India and the reasons of it are many. Many poisons apart from corrosives and irritants do not show characteristic post-mortem signs and one of the biggest issues is that only common poisons are tested. This factor combined with the lack of legislation on procedures governing the collection and storage of the samples often leads to a negative FSL report even when there are clear signs of poisoning. This makes it very difficult to ascertain the exact cause of death in the post-mortem report. Further, there are occasions when the FSL report is not brought on record even though the samples have been sent to the Chemical Examiner for analysis. FSL report, though not mandatory in all cases, plays an important role where the allegations pertain specifically to death by poisoning. The absence of the FSL report or a negative FSL Report weakens the prosecution case substantially as not every case has adequate circumstantial evidence to prove that the deceased was administered poison by the accused. The conclusion of cause of death in a case where the death is due to poisoning but viscera report gives negative result, poses confusion to the autopsy doctor, law and public. The salient points covering various aspects of negative viscera report with special reference to the false positive or false negative results and its effect on criminal judicial system in conviction and acquittal along with suggested remedies are to be discussed here.