Effects of Flunitrazepam Drug on the Decomposition Process of Pigs Liver in PMI Determination: A Histopathology Perspective

Background Decomposition can be retarded by several processes, including physical and chemical barriers and climatic factors. The presence of flunitrazepam (Rohypnol®) in the bodies may interfere with the decomposition process by inhibiting enzymatic activity, particularly in the liver making it difficult for experts investigating a forensic case to determine the post mortem interval. This study investigated the effect of flunitrazepam in alcohol (40%) on the decomposition of pig liver to provide a guiding standard for postmortem interval (PMI) determination in cases involving flunitrazepam ingestion. Methods Two pigs (Sus Scrofa L.), aged six months and weighing 24.6 kg and 25.2 kg, were selected to ensure physiological uniformity. Using two pigs balanced logistical constraints while providing sufficient data for preliminary analysis. One pig served as a control, while the experimental pig was administered 2 mg of flunitrazepam dissolved in 250 ml of vodka to mimic a common practice of spiking in a bar setting. The pigs were euthanized using an electric stunning method, ensuring a humane procedure. Liver samples measuring 2 cm x 2 cm were randomly excised daily from the caudal lobe and preserved in 10% neutral buffered formalin. Sampling was monitored every 24 hours over 16 days. Results These findings underscore flunitrazepam’s significant impact on decomposition, aiding forensic PMI determination. Histopathology was conducted on all liver samples to determine the structural and cellular changes consistent with autolysis daily for 16 days. The study found, flunitrazepam slowed down the decomposition process of pigs’ liver in PMI determination in the period between day 1 and day 6. However, the effect of flunitrazepam drugs on the decomposition process of pigs’ liver was absent after day 6. Conclusions Forensic investigators should account for flunitrazepam’s impact on postmortem interval (PMI) when determining time of death in forensic cases.