Superimposition of ante- and post-mortem photographs of tattoos as a means of identification--a case report

With the rising number of tattooed people tattoos have become increasingly important for the identification of unknown corpses. Tattoos can be helpful in both phases of the identification process, either by providing clues to the identity of an unknown person or body or as a means of verifying a postulated identity. In the presented case, an ante-mortem photograph of a tattoo was available although it was of poor quality. The respective skin region of the body was photographed from the same angle as the tattoo on the ante-mortem photograph. When superimposing the two photos, the tattoos were found to match and the identity of the body could be verified.     

A study to narrow down the time when a hyoid bone fracture was sustained

An unstable hyoid bone that can be loosely moved during autopsy is initial reason to suspect trauma to the neck. The question to be answered is whether the increased mobility is due to incomplete ossification of the hyoid, a postmortem injury (damage), or an ante-mortem injury, possibly related to the cause of death. This is the first study to systematically assess whether stereomicroscopic examinations and flat-panel CT-scans of isolated, unstable hyoid bones can add information to the macroscopic examination by helping to determine when the instability arose. Sixteen isolated hyoid bones (8 female, 8 male; 4-87 years-old) were examined after being macerated. Four of the hyoid bones were already classified as unstable during autopsy. Of the other 12, 7 were fractured immediately after autopsy before being macerated, and 5 were fractured after being macerated. There were, in total, six different diagnostic constellations. Stereo-microscopic examination did not yield additional information compared with the macroscopic examination. Flat-panel CT allowed distinction between an incomplete ossification of the hyoid and a fracture, but did not help in determining whether the fracture had been sustained peri- or postmortem.     

Differentiation of epithelial cell types by cell diameter

Genital swabs play an important role in cases of alleged sexual assault. The aim of our study was to see if epithelial cells from the vagina, glans penis, or mouth could be distinguished on the basis of size. Vaginal swabs were taken from 12 women in different phases of their menstrual cycles; penile swabs were taken from 5 men, and mouth swabs were taken from 6 men and 6 women. For each swab, a sample was smeared across a microscope slide and allowed to dry. The dried epithelial samples were then viewed without any further processing with a "SteReoLumar.V12" stereo microscope. The microscope slide surfaces were divided into grids and all single epithelial cells whose contours could be clearly distinguished were photographed. The maximum diameter for each photographed cell was digitally determined using the Axiovision software. In total, 995 vaginal epithelial cells, 211 penile epithelial cells, 329 male oral epithelial cells, and 525 female oral epithelial cells were measured. Menstrual cycle phase did not affect vaginal epithelial cell diameter. The mean vaginal epithelial cell diameter was 63.95 microm (min. = 28.08 microm, max. = 108.06 microm, s = 11.50 microm). The mean penile epithelial cell diameter was 39.24 microm (min. = 28.38 microm, max. = 51.02 microm, s = 4.84 microm). The diameter of oral epithelial cells hardly differed for both sexes, although the female cells were, on the whole, slightly larger. On the basis of these results, it is not possible to conclude that epithelial cells of less than a certain diameter found in the assessment of a vaginal swab must be of penile origin. It is also not possible to usefully distinguish vaginal epithelial cells from male or female oral epithelial cells on the basis of the diameter. However, finding epithelial cells with a diameter distinctly greater than 50 microm in a penile swab sample suggests the presence of vaginal or oral epithelial cells. Epithelial cells examined with the presented method can be used without restrictions for further examinations, such as single-cell DNA analysis after single-cell picking with the micromanipulator developed by Aura Optik (Jena).     

Comparative dental radiographic identification using flat panel CT

A skull without lower jaw was found and brought in for identification. It was suspected to be that of a man reported missing five years ago. An undated antemortal dental chart and two dental films of the 1st and 2nd dental quadrants, both taken about 4 years before the man went missing, were available for comparison. The method of choice in solving the identity question was comparative dental radiography. Despite numerous attempts, it was not possible to obtain radiographs of the upper jaw that duplicated the X-ray beam angulation of the antemortem dental films. The skull was thus scanned with a multislice computed tomography (MSCT) scanner, and virtual radiographs with the desired angulation were generated from the data with the maximum intensity projection (MIP) technique. The resulting virtual radiographs could, however, not be used for superimposition with the antemortem radiographs because of their poor resolution and the occurrence of artifacts caused by metallic dental fillings. The upper jaw was therefore scanned again, this time with a high resolution eLU-CT (eXplore Locus Ultra flat panel CT). The resulting eLU-CT datasets were visualized with the MIP technique and yielded virtual radiographs that could be compared with the antemortem radiographs. Positive identification could be assumed with near certainty after dental features could be matched in the superimposition of antemortem and postmortem radiographs. In the presented case, eLU-CT was used for the first time for a comparative dental radiographic identification.     

Postmortem interval of skeletal remains through the detection of intraosseal hemin traces. A comparison of UV-fluorescence, luminol, Hexagon-OBTI®, and Combur® tests

With the goal of obtaining additional practically applicable methods for estimating the PMI of skeletal remains, 39 samples of human and 5 samples of domestic animal long bones with known PMI (PMI=1 to approximately 2000 years) were tested with two established methods (UV-fluorescence of a freshly sawn cross-section and the luminol test) and two screening tests (Hexagon-OBTI? test and Combur? test) that were being tried out in this context for the first time. The hypothesis underlying this experiment was the supposition that the PMI-related chemiluminescence of the luminol reaction for bone is based on the presence of persisting hemin from hemoglobin molecules in bone. Our results showed that lack of luminescence and reduced UV-fluorescence were more meaningful results for estimating PMI and excluding forensic relevance than a positive luminol reaction or strong UV-fluorescence, as both of the latter findings revealed the limitations of these methods in this particular context. Particularly for cases showing a positive luminol reaction, the use of additional absolute dating methods may be indicated. Against our expectations, both the Combur? test strips and the Hexagon-OBTI? test, which were both devised to demonstrate blood, delivered negative results for all samples. They are thus not suitable for estimating the PMI of skeletal remains. Future research will be necessary to elucidate whether the negative results obtained for these tests may be due to the poor solubility of potentially present hemoglobin or hemoglobin breakdown products in the Tris buffer used in this experiment.     

Initially suspected killing with a political background identified as accidental carbon monoxide poisoning

During a parish fair the police was called to a conflict between two rival right-wing youth groups in the early morning hours. Shortly afterwards a burning car was discovered near the marquee with a charred male body on the driver's seat. It was assumed that there was a connection between the two events. At autopsy no injuries were found that were not attributable to postmortem consumption by the fire. The BAC value was 1.76 per thousand, the CO-Hb concentration 78%. The body could be identified by comparing pre- and postmortem X-rays of the molars and premolars of the right upper jaw. Reconstruction of the course of events and classification as an accident was possible only after calling in technical experts: The victim had gone back to his car to take a nap and kept the engine running because of the cold temperature. The car had been fitted improperly with a sport exhaust pipe, which caused both the carbon monoxide poisoning and the fire.     

Application of the hexagon-OBTI test and the RSID blood test for the determination of the post-mortem interval of bone samples

In this serial experiment, five human bones with known post-mortem intervals (PMI) in a soil environment from five different epochs (0.2 to approximately 2000 years) were tested in a blind setup with two established rapid tests for the identification of human blood traces (Hexagon-OBTI test and RSID blood test). Based on previous study results concerning the usability of the Luminol test for the first assessment of the PMI of osseous remains, the question arising was whether those test procedures, which are highly sensitive for the detection of human blood components, could also be used to narrow down the post-mortem interval. Five test series were conducted applying modified standard protocols of the manufactures. The aim was to find out whether with prior reaction steps or a prolonged time of incubation hemoglobin or its metabolites can be dissolved from the bone and positive test results can be achieved dependent on the PMI. Four test series yielded negative results for all bone samples and one test series a uniformly weak positive result. The results indicate that rapid tests based on the detection of blood are not suitable for the determination of the PMI of bone samples despite the modification of the standard protocols. Further thorough research is required to clarify the postmortem degradation of hemoglobin in bones.     

The value of skull-photo superimpositions in identifying corpses found in domestic settings

The identification of decomposed corpses found in domestic settings is frequently problematic because comparative material for methods such as forensic odontostomatology, comparative X-ray analysis, or DNA analysis, is not available. In the case presented here, a photograph from an old, expired passport could be used to successfully identify a "domestic setting" corpse in a skull-photo superimposition. In an additional DNA analysis, 13 STR-loci could be amplified from tissue samples taken from the corpse. DNA comparison with the presumed brother of the deceased yielded a probability of 97.09% for siblingship. Y-STR-analysis was, therefore, performed. The results showed that all of the systems for the presumed brother and the corpse conformed, with the exception of the DYS390 locus, in which allele 21 was found for the corpse and allele 22 for the brother. Despite the rapid development of other identification procedures, skull-photo superimpositions remain an important means of identification. Last not least this is due to the increasing ubiquity of personal photo documents in the age of digital photography. The validity of the results from a DNA analysis in an identification process depends largely on the authenticity of the samples available for comparison and the degree to which the DNA from the corpse is preserved. In the case presented by the authors, positive identification of the corpse solely on the basis of the DNA analysis would not have been possible. Numerous constellations can be imagined for decomposed corpses found in domestic settings for which skull-photo superimpositions may be the only possible option for identifying the corpse.     

Criteria for the classification as a "domestic-setting corpse"--a literature search and review to define the term

In German medical and media circles (daily routine, specialist literature, press, novels), the term "domestic-setting corpse" is frequently used, but the term is only vaguely defined. The authors thus decided to perform an in-depth study of the literature, including historic textbooks and all German- and English-language medicolegal journals, going as far back as their first issues, in an attempt to more clearly define the term. Inclusion criteria used in the search were a post-mortem interval of at least 24 hours prior to discovery and discovery of the corpse in a domestic setting. In the literature, 37 cases that complied with the above-mentioned inclusion criteria were found. These cases frequently described "advanced decomposition", often "unclear cause of death" and "problems in identification". These characteristics can thus be considered as being additional pointers in the definition. However, we suggest that the two general defining characteristics of a "domestic-setting corpse" are a post-mortem interval of more than 24 hours before discovery and the discovery of the corpse in a domestic setting.