Conclusion

During Springfield, we (Department of Forensic Entomology - IRCGN, France) were called for entomological sampling on a corpse buried at about 80 cm depth in the West of France (Fig. 13.5). The soil was mainly composed by clay. A layer of farm quicklime (about 20 cm) covered the corpse from 40 cm depth onward. The victim was supposed to be killed 6 months ago. We collected larvae, many pupae and empty pupae of Heleomyzidae, some pupae and empty pupae of Megaselia sp. (Phoridae) and adults of Sphaeroceridae and Aleocharinae sp. Heleomyzidae and Sphaeroceridae were found in the wax layer covering the body between 40 and 60 cm depth. Phoridae were collected from the hairs of the victim at about 90 cm depth (Fig. 13.3). Phoridae were collected in large quantity. Several generations in burial environment may have succeeded without being able to precise more. Pupae of Heleomyzidae were hard to identify until the species' taxonomic level. Presence of adults of Sphaeroceridae and Aleocharinae sp. was not very helpful in the expertise work. In that situation, estimation of PMI was hard to make.

Fig. 13.5 Illegal grave with a body initially buried at 80 cm depth (Photography: E. Gaudry, IRCGN, France)

However, the absence of Calliphoridae or Sarcophagidae may indicate burial a short while after death (the time of homicide was supposed to occur in early autumn under good condition of temperature). In this case, burial has very likely inhibited post-burial colonisation.

In the West of France, during summer (at the end of July), a cadaver was found buried at 20 cm depth in an uncultivated field. The body was wrapped in a carpet (Fig. 13.6). A large population of insects was collected:

- Sarcophagidae (empty pupae)

- Muscidae: Muscina sp. (empty pupae), Ophyra ignava (Harris) (empty pupae)

- Phoridae (empty pupae)

- Nitidulidae: Carpophilus sp. (adult), unidentified (larvae)

- Staphylinidae: Creophilus maxillosus (Linné) (adult), Gauropterus sp. (adult), Aleocharinae (adult), Staphylininae (adult)

- Histeridae: Saprinus semistriatus (Scriba) (adult)

- Scarabaeidae: Onthophagus ovatus Linné (adult)

The analysis was based upon the hypothesis of time of emergence on the day of sampling. With such a hypothesis, a minimum PMI was estimated at least 6 weeks before. Recent information from investigators revealed that the time of death was established at the middle of May, which was 10 weeks ago. In the present case study, burial and wrapping delayed the arrival and colonisation of the body by insects but did not

Fig. 13.6 Illegal grave with a body initially buried at 20 cm depth. (Photography: Gendarmerie Nationale, France)

inhibit it helping the PMI estimation. This case study can be listed in the shallow grave category. Such estimation provided to investigators was then very important to identify the victim.

Motter (1898) argued about the notion of seasonality in the presence of certain species (e.g. presence of Muscidae indicating burial in summer and not in winter). He rather preferred to state that such presence may be due to exposure of the bodies to more favourable temperatures for the post-embryonic development of these species. He observed, as occurred for exposed cadavers, a chronological succession arrival of the various species colonising the bodies within distinct waves at specific periods of decay.

Lerclercq reported in 1993 a case dating from 1974 where a cadaver was found buried at 50-60 cm depth in a claying soil during the autumn season. On the remains that appeared at the surface of soil, entomologists identified Limosina (paracollinella) curvinervis (Diptera, Sphaeroceridae), Brachyopa sp. (Diptera, Syrphidae) and Coprophilus sp. (Coleoptera, Staphylinidae). Lerclercq wrote in his article that the victim was deceased 1 year ago without specifying further the implication of the entomological evidence in this expertise work.

These non-exhaustive cases reveal that the study of entomofauna associated with buried carrion needs further experiment and observation. Better knowledge of the impact of intrinsic and extrinsic factors such environment (temperature, rain, wind, etc.), and physical parameters of the burial site (depth, soil type, moisture, air content, temperature, etc.) are needed too.

Among the necrophagous population collected on buried corpse and its surroundings, whose composition may be significantly different than on the surface, species initially considered as groups of secondary importance may have a more important role in estimating PMI using ADD or ADH. Interaction between arthropod species (predation, parasitism, succession) needs further studies and can be an interesting option just as interaction between insects and fungi.

The discovery of a buried cadaver (criminal case, mass grave, disaster) is uncommon and often becomes a media event. Criminal investigations are no more confined only to the competence of magistrates and investigators. The public demands information, and the media need topics for reporting. Magistrates and investigators need to solve cases in such conditions. Forensic sciences are still developing and their importance in investigation is still growing. Techniques are becoming more and more efficient.

Accidental exhumation of buried corpses, but also requirement by authorities for investigating purposes, or second expert opinion or identification of victims (natural disaster or accident) may demand growing implication of forensic specialists such as forensic entomologists.

Study of this necrophagous population can give useful information, even if the PMI estimation is less easy to determine. Progress in the last 50 years has been significant thanks to several authors. Advances in this particular field of forensic entomology need improvement in the accuracy and reliability of the analyses in.

Acknowledgements Jens Amendt, Institute of legal Medicine, Frankfurt am Main - Germany. Jean-Pol Beauthier, Laboratoire de médecine légale et d'anthropologie médico-légale, Bruxelles -Belgique. Laurent Chartier, Département Signal image parole, IRCGN, gendarmerie nationale - France. Jérôme Carlier, Département Signal image parole, IRCGN, gendarmerie nationale -France. Laurent Dourel, Département Entomologie, IRCGN, gendarmerie nationale - France. Fabrice Galli, Centre national d'instruction cynophile de la gendarmerie nationale - France. Dorothy Gennard, Lincoln University, Lincoln - United Kingdom. Jean-Bernard Huchet, université de Bordeaux 1, Bordeaux - France. Hans Huijbregts, National Museum Natural History, Leiden - Nederland. Yvan Malgorn, IRCGN, gendarmerie nationale - France. Guy Marchesi, Service central de renseignements judiciaires et de documentation, gendarmerie nationale -France. Jean-Jacques Menier, National History Museum, Paris - France. Jean-Bernard Myskowiak, Département Thanotologie anthropologie odontologie, IRCGN, gendarmerie nationale - France. Thierry Pasquerault, Département Entomologie, IRCGN, gendarmerie nationale - France. Patrick Perrot, Département Signal image parole, IRCGN, gendarmerie nationale - France. Henri Plouchart, Direction Centrale de la Police Judiciaire - France. Géraldine Salerio, Institut de médecine légale de Montpellier - France. Jean Richebe, Département Thanotologie anthropologie odontologie, IRCGN, gendarmerie nationale - France. Stefano Vanin, Université di Padova, Padova- Italia. Benoît Vincent, Département Entomologie, IRCGN, gendarmerie nationale -France.

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