Forensic Taphonomy Unit

Saint-André-lez-Lille, France

Forensic Taphonomy Unit

Saint-André-lez-Lille, France
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Broucker A.D.,University Of Lille F 59000 Lille | Colard T.,University Of Lille F 59000 Lille | Colard T.,Forensic Taphonomy Unit | Penel G.,University Of Lille F 59000 Lille | And 2 more authors.
International Journal of Paleopathology | Year: 2015

Estimating an individual's age at death is essential for post-mortem identification, paleopathology and paleodemography. With substantial development over the past 10 years in cementochronology analyses, some concerns have arisen that oral pathological conditions may artificially reduce or increase cementum apposition.The objective of this study was to observed the impact of periodontal disease on acellular cementum and on the reliability of cementochronology to test its accuracy for estimating individual age at death. The study included 41 teeth presenting different degrees of bone destruction, extracted from 18 individuals affected by untreated periodontal disease.The results demonstrated that the degree of alveolysis had only limited effects on the counting of cementum annulations in the middle (rp = 0.92,. p <. 0.01 between estimated and civil age) and the cervical (rp = 0.85,. p <. 0.01) thirds of the root, whereas in the apical third, the increments were affected considerably. This cementum reactive process compensates for bone destruction and loss of the attachment apparatus. These data suggest that cementum could continue to grow at a slower rate despite bone destruction due to periodontal disease. Cementochronology can thus be applied to teeth with a damaged periodontium by sectioning the middle third of the root. © 2015 Elsevier Inc.


Colard T.,University of Lille Nord de France | Colard T.,Forensic Taphonomy Unit | Delannoy Y.,University of Lille Nord de France | Delannoy Y.,Forensic Taphonomy Unit | And 6 more authors.
Legal Medicine | Year: 2013

Postmortem investigations are increasingly assisted by three-dimensional multi-slice computed tomography (3D-MSCT) and have become more available to forensic pathologists over the past 20. years. In cases of ballistic wounds, 3D-MSCT can provide an accurate description of the bullet location, bone fractures and, more interestingly, a clear visual of the intracorporeal trajectory (bullet track). These forensic medical examinations can be combined with tridimensional bullet trajectory reconstructions created by forensic ballistic experts. These case reports present the implementation of tridimensional methods and the results of 3D crime scene reconstruction in two cases. The authors highlight the value of collaborations between police forensic experts and forensic medicine institutes through the incorporation of 3D-MSCT data in a crime scene reconstruction, which is of great interest in forensic science as a clear visual communication tool between experts and the court. © 2013 Elsevier Ireland Ltd.


Charabidze D.,University of Lille Nord de France | Charabidze D.,Forensic Taphonomy Unit | Colard T.,University of Lille Nord de France | Colard T.,Forensic Taphonomy Unit | And 4 more authors.
Forensic Science International | Year: 2014

We describe new experimental data for the defleshing of human bones using larder beetles (Dermestes haemorrhoidalis) (Küster, 1852). Although the ability of larder beetles to feed on vertebrate remains has been, and still is, used by taxidermists to deflesh skulls and bones, this method has never been documented from a quantitative perspective and has over time become ignored in most forensic anthropology or odontology laboratories.To promote the rational and efficient use of this method, we performed experiments to estimate the quantity of food consumed by larvae. From the 2nd instar to nymphosis, each larva consumed a mean of 0.13 ± 0.03. g of dry beef muscle. We then used 100 ± 50 D. haemorrhoidalis adults and 100 ± 50 larvae to deflesh human maxillae and mandibles sampled within a forensic context (victim identification). Each sample was weighed and photographed before, during and after the experiment. According to our experiments, 20-25 days were sufficient to completely deflesh all of the samples.We concluded that a small number of larder beetles can be used to efficiently deflesh human jaws. According to this result, the use of larder beetles appears to be an inexpensive, simple and efficient way to clean mandibles and maxillae. Furthermore, this method is DNA-safe (compared to usual maceration techniques) and thus allows the samples to be used for subsequent DNA and drug analyses. © 2013 Elsevier Ireland Ltd.


Charabidze D.,University of Lille Nord de France | Charabidze D.,Forensic Taphonomy Unit | Depeme A.,University of Lille Nord de France | Depeme A.,Forensic Taphonomy Unit | And 5 more authors.
Forensic Science International | Year: 2015

This study was designed to examine the common belief that necrophagous blowflies lay their eggs in wounds.The egg-laying behaviour of Lucilia sericata was observed under controlled conditions on wet, artificially wounded or short-haired areas of rat cadavers. Flies laid significantly more eggs on the wet area and the area with short hair than on the dry area or area with long hair. No eggs were observed inside the wounds in any of the replicates.The effect of egg immersion (body fluids often exudes in wounds) on the survival rate of larvae was also investigated. In low water condition, an average of 72.7 ± 7.9% of the larvae survived and they reached a mean length of 7.5 ± 0.6 mm In contrast, submerging eggs under a high volume of water strongly affected their survival rate (25 ± 3.7%) and development. Similar results were observed using unfrozen pig blood instead of water.These data question the information found in the literature regarding the preferential egg-laying behaviour of Calliphorids flies in wounds. © 2015 Elsevier Ireland Ltd.


Colard T.,Lille University of Science and Technology | Colard T.,Forensic Taphonomy Unit | Delannoy Y.,Lille University of Science and Technology | Delannoy Y.,Forensic Taphonomy Unit | And 6 more authors.
Journal of Forensic Sciences | Year: 2015

Postmortem animal mutilations due to domestic dogs in isolated domestic deaths are taphonomic modifications regularly observed by forensic pathologists. They are rarely described in the literature; however, even though they present specific patterns. Through 41 cases, 10 at the forensic institute in Lille (France) and 31 at the New York City Office of Chief Medical Examiner (USA), plus 22 cases from the literature, specific locations and patterns of postmortem scavenging lesions are proposed. These lesions are mainly distributed in three locations: the face, especially the nose and the mouth (73.1%), the neck (43.1%), and the arm (shoulder/upper limb [29.2%], hand [26.8%]). We discuss the time span between death and scavenging, the consequences on identification, and comparison with outdoor settings. Outdoor scavenging lesions are mainly located on the trunk and limbs usually sparing the head, which strongly differs from indoor distribution and imply different animal motivations. © 2015 American Academy of Forensic Sciences.


Charabidze D.,University of Lille Nord de France | Charabidze D.,Forensic Taphonomy Unit
Annales de la Societe Entomologique de France | Year: 2012

Necrophagous insects and forensic entomology. The estimation of the time of death is one of the major issues when a body is discovered. For this purpose, forensic entomology use insects sampled on corpses to estimate a minimum post-mortem interval (PMImin) and the time of death. This field of forensic sciences and legal medicine thus needs detailed knowledge regarding the development and physiology of the species of forensic interest. Such knowledge is provided by constant research in field and laboratory conditions. The goal of these studies is not only to develop new methods for PMI estimation improvement. Forensic entomology research also allows a better comprehension of several areas of the biology of necrophagous species. This review presents on a fi rst part the development of necrophagous species, and especially blowfl ies larvae (Diptera Calliphoridae). In a second part, the current concepts in forensic entomology allowing PMI estimation are explained. © Société Entomologique de France.


Charabidze D.,University of Lille Nord de France | Charabidze D.,Forensic Taphonomy Unit | Hedouin V.,University of Lille Nord de France | Hedouin V.,Forensic Taphonomy Unit | And 2 more authors.
Journal of Insect Physiology | Year: 2013

Larvae of the necrophagous Blowfly Lucilia sericata (Diptera Calliphoridae) live on vertebrate cadavers. Although continuously feeding was previously assumed for this species, we hypothesized that larvae do not feed constantly. According to this hypothesis, their crop should not always be full, which should be reflected in crop surfaces. We dissected and measured the crops of larvae of the same age and bred in the same conditions. Crop surfaces of 117 larvae just removed from the food ranged from 0 to 16.6mm2 (mean=5.325±2.84mm2). The distribution of these crop surfaces indicates a continuous variation of satiation/feeding activity in the population. Starving experiments showed a quite long digestive process. After 90min of starving, the decrease in crop surfaces became obvious, but 150min were necessary to observe more than a half of the population with an empty crop (less than 2mm2). No more differences were observed after 150, 180 and 240min of starving. We finally used starved larvae to observe the kinetic of food absorption and the duration of the food-intake phase. Our results indicates that larvae can ingest faster than they digest. After 5min spent in the food, 70% of the larvae had a crop surface larger or equal to 8mm2. We observed for the first time an over-feeding of the larvae, with high crop surfaces overrepresented compared to larvae never starved (control).Together, these results indicate that larvae do not feed continuously, and regulate their foraging behavior. We propose that the foraging behavior of the larvae creates a permanent movement inside the larval masses. This turnover/scramble competition may be linked to the larval-mass effect, i.e. the local temperature increase observed in large necrophagous larvae aggregates. © 2013 Elsevier Ltd.


Aubernon C.,University of Lille Nord de France | Aubernon C.,Forensic Taphonomy Unit | Devigne C.,University of Lille Nord de France | Devigne C.,Laboratoire Ecologie and Biodiversite | And 6 more authors.
Journal of Forensic Sciences | Year: 2015

Several parameters can delay the first arrival of flies on a corpse and the subsequent development of the larvae. This study focuses on the development of Lucilia sericata (Diptera: Calliphoridae) (Meigen, 1826) on household chemical-contaminated substrates. bleach, perfume, hydrochloric acid, caustic soda, insecticide, mosquito repellent, and gasoline in quantities consistent with an amount that could possibly be spilled on a corpse were mixed with beef liver to simulate contaminated fleshes. Larvae were bred at 25°C on these media until emergence. Four developmental parameters were followed: survival rates, development times, sex ratios, and adult sizes. Hydrochloric acid, insecticide, and gasoline killed all larvae. In low quantities, caustic soda and mosquito repellent increased the development time and decreased the adult size. However, high quantities of these chemicals killed all larvae. Lastly, bleach and perfume did not affect the survival rate and barely impacted the development time or adult size. These results demonstrate common household products spilled on a corpse can strongly affect the development of Calliphoridae larvae. The effects of such products should be considered in forensic entomology cases. © 2014 American Academy of Forensic Sciences.


Boulay J.,University of Lille Nord de France | Boulay J.,Forensic Taphonomy Unit | Boulay J.,Free University of Colombia | Devigne C.,University of Lille Nord de France | And 5 more authors.
Animal Behaviour | Year: 2013

Vectors of aggregation are well known for some arthropod species, but not for many others. We aimed to describe larval aggregation (experiment 1) in the carrion fly, Lucilia sericata (Diptera: Calliphoridae), and to investigate the effect of food and conspecifics on larval behaviour (experiment 2). In experiment 1, 40 larvae were placed in a petri dish with a homogeneous diet for 30. min, 1. h, 3. h, 5. h or 24. h. This experiment demonstrated for the first time under controlled conditions the active aggregation of L.sericata larvae. The results indicate that the aggregation took place quickly and was reinforced with time. After only 3. h, one main aggregate comprising a majority of individuals was observed. These results also highlight the likely use by necrophagous larvae of a signal left by conspecifics as an aggregation vector. In experiment 2, we used a video-tracking system to investigate whether such an aggregative signal exists. Fed and starved larvae were tracked for 5. min in a circular area with each half marked with a different signal combination. The time spent in the signal zones, the distance travelled, the velocity, the time at the stop and the number of stops in each zone were measured. The larvae were significantly retained by a signal (mark) left by conspecifics. Together, the results of this study demonstrate the existence of a contact and/or odour-mediated signal involved in the aggregative behaviour of necrophagous larvae. © 2013 The Association for the Study of Animal Behaviour.

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