Application of Entomology in Some Medicolegal Issues

As the application of the forensic entomology has been strongly criticized for years, the present study was carried out on fifteen cases representing all putrefied cases in different seasons and habitats with larval infestation referred to the Forensic Medicine Directorate in Middle Delta. The aim of the present study was to identify and record the different species of insects that are frequently associated with human corpses to establish data base for the potential use of insects as postmortem interval indicators. The maximum number of cases was in the age group 10-20 years, and the least number was encountered in the age group less than 10 years and over 50 years. A relatively larger number of victims (73%) were males while female corpses were (27%) in this study. Nine of the reported cases (60%) were exposed, while, the other six cases were equally distributed between aquatic locations and burial (20% for each). The maggots recovered from the fifteen decomposing human remains belong to family Calliphoridae and Sarcophagidae (Diptera). The blow fly Chrysomya albiceps was the most common species invading nine cases (60%), followed by Sarcophagidae family (four cases with a percentage of 26.7%). The least number was Psychoda and Lucilia sericata which infested only one case for each (6.7%). This study revealed that, Chrysomya albiceps was found to be a highly indicative species to corpses found in urban (6 cases) and rural (3 cases) areas representing 67% and 33% on sequence during the warmer seasons. While both Sarchophagidae and Dermistidae were equal in both urban and rural areas. Lucilia sericata and Psychoda species were only present in rural areas in this study. In the present study Chrysomya albiceps was attracted to corpses in spring (5 cases), summer (2 cases) and winter (2 cases). Sarcophaga species larvae were infesting dead bodies in both spring (3 cases) and fall (1 case) representing 75% and 25% respectively. Luicilia sericata larvae were collected from 1 case in winter. Psychoda species and Dermestidae larvae were collected from cases in spring only. In the present study, 3 cases were found to be of interest to forensic entomology. The first case concerned a corpse of young female killed by smothering, the second was exhumated for autopsy and the third one was partially submersed and killed by strangulation and found near a water canal coast. The implications for estimation of postmortem interval by entomological methods were discussed. The results of this study demonstrated the usefulness of testing larvae associated with decomposed remains for toxicological analyses in cases number 12 & 14 as the cause of death was carbamate and organophosphorus toxicity respectively. This study concluded that, in death cases where insects are associated with the remains, it can be used for detection of postmortem interval and the cause of death in some cases. The forensic entomologist should cooperate with the forensic pathologist; from the visual observations of the cadaver in the scene, through the collection of insects and temperature data up to the final report with the interpretation of entomological and other biological evidence.