Evaluation of porcine decomposition and total body score (TBS) in a central European temperate forest.

The total body score (TBS) is a visual scoring method to scale the succession of decomposition stages. It compares decomposition between cadavers, to connect it with external taphonomic factors and estimate the post-mortem interval. To study decomposition in various climatic environments, pigs are often used as human proxies. Currently, there is one TBS system by Keough et al. (J Forensic Sci. 2017;62:986) for surface-deposited domestic pigs, coming from South Africa. Our study aims to evaluate this method and analyze porcine decomposition in Central Europe to inform forensic research and casework. We conducted an experiment studying six 50 kg pig carcasses in a temperate Swiss forest. Three observers documented decomposition patterns and rated the decomposition stages from photographs based on the porcine TBS model by Keough et al. (J Forensic Sci. 2017;62:986). We documented discrepancies between the carcass decomposition of our specimens and those in the South African study, especially related to the high insect activity in our experiment. Furthermore, we noted factors complicating TBS scoring, including rainfall and scavengers. The agreement between TBS observers from photographs was in the highest agreement category apart from one "substantial agreement" category. Our study is the first in Europe to systematically test the Keough et al. (J Forensic Sci. 2017;62:986) method. The results evidence that regional adaptations are required to be applicable for other environments. We present a modified approach based on experimental observations in a Swiss temperate forest. The identification of regional decomposition patterns and drivers will inform future taphonomy research as well as forensic casework in comparable contexts in Central Europe.

Cat and dog scavenging at indoor forensic scenes: strategies for documentation and detection.

Vertebrate scavenging on human remains is occasionally observed at indoor forensic scenes, especially when pets have access to the body and their deceased owners were socially distanced. Pets feeding on corpses have implications for the forensic investigation, e.g. for trauma analysis and the assessment of the cause of death, the estimation of the postmortem interval (PMI), or the recovery of the complete set of remains. Documentation of potential scavenging in forensic practice is tenuous and needs to be improved in order to be able to use the information for future casework. Investigators need to be aware of the alterations pets can cause to human remains and how these affect further analyses. Following a combined literature review for cat and canine scavenging, we present seven new cases from Switzerland with cat and/or dog involvement. We then created a flowchart guide for a systematic collection of data to use at indoor forensic scenes of suspected scavenging. Our literature review revealed the challenge in discriminating between scavenging by domestic cats and dogs, based on the appearance of the lesions alone. Furthermore, the information that is often routinely collected in indoor fatalities with potential scavenging activity is not sufficient to perform this separation. To provide a practical basis for cat and canine scavenging and its differentiation, we summarise strategies and present a flowchart to use in forensic casework of suspected indoor scavenging.

Forensic experiments on animal scavenging: A systematic literature review on what we have and what we need.

Vertebrate scavengers frequently affect forensic casework by feeding on human remains or by scattering body parts and bones. Therefore, animal activity can influence complete recovery of bodies, trauma analysis, and the estimation of the postmortem interval (PMI), potentially hampering identification of the deceased and elucidation of the perimortem circumstances. Experimental research is well suited to investigate scavengers and their impact on carcasses over time, generating knowledge on the forensic relevance of certain scavenger species or communities. However, there are currently no systematised standards to conduct these investigations with a forensic focus, impeding comparison and synthesis of the studies. In our work, we performed a systematic literature review and found 79 publications featuring terrestrial experiments on vertebrate scavenging and/or scattering within a forensic context. We extracted 21 variables describing the study environment, experimental design and the specimens. The results show that there is considerable inconsistency in the study designs and that some of the variables are insufficiently reported. We point out research questions and areas that require attention in future studies, stressing the importance of infrequently mentioned or applied variables. Furthermore, we recommend guidelines to include and report a list of variables in forensic scavenging and scattering experiments. These guidelines will help standardising future research in the field, facilitating inter-study consolidation of results and conclusions, and consequently, inform forensic casework.

Perimortem Skeletal Sharp Force Trauma: Detection Reliability on CT Data, Demographics and Anatomical Patterns from a Forensic Dataset.

The increasing importance of trauma analysis by means of postmortem computed tomography (PMCT) is insufficiently reflected in forensic curricula, nor are best practice manuals available. We attempt to detect sharp force bone lesions on PMCT of closed forensic cases with the aims of assessing errors and pointing out patterns in anatomical location and manner of death (MOD). We investigated 41 closed sharp force fatality cases, with available PMCT and forensic reports. Two observers with different radiological training assessed the lesions on PMCT scans (2D and 3D) for comparison with the reports. Between 3% (suicides) and 15.3% (homicides) of sharp force injuries caused visible bone lesions. While our observations were repeatable, each forensic investigation left a similar number of bone lesions undetected. Injury patterns differed between MOD, with thoracic bone lesions being most frequent overall. Soft tissue injury location varied between the MOD. Associations between MOD and age as well as number of injuries were significant. The detection of bone lesions on PMCT for untrained forensic specialists is challenging, curricula and pertinent manuals are desirable. With the low frequency of bone lesions compared to soft tissue injuries, we should be aware when analyzing decomposed bodies.

Uncovering Forensic Taphonomic Agents: Animal Scavenging in the European Context.

Animal scavenging by vertebrates can significantly alter human bodies and their deposition site. For instance, vertebrate animals can cause postmortem modification to a body, alter perimortem trauma, influence decomposition rates, disarticulate and scatter body parts or evidence, and affect the identification of the deceased. Animal scavenging is a relatively common occurrence in forensic investigations. Even so, studies on the subject are scattered and rare, with most focussing on geographical areas outside of Europe. For that reason, we intend to collate the literature to provide an account of forensically relevant vertebrate scavengers in Europe, their impacts on human remains, and their implications for forensic investigations. Here, we provide an overview of forensic aspects where the knowledge of animal scavenging is crucial, as well as an account of potential scavengers of human remains in Europe and their typical alterations to soft tissue and, in particular, to bones. In addition, we are the first to provide a guide for forensic practitioners to identify the presence of vertebrate scavenging and subsequently inform outdoor search strategies for affected human remains.

Testing the validity of population-specific sex estimation equations: An evaluation based on talus and patella measurements.

Sex estimation is essential for forensic scientists to identify human skeletal remains. However, the most sexually dimorphic elements like pelvis or skull are not always assessable. Osteometric analyses have proven useful in sex estimation, but also to be population specific. The main purpose of this study was to test the validity of contemporary Greek and Spanish discriminant functions for the talus and the patella, respectively, on a Swiss skeletal sample and to quantify the utility of the measurements as a novel approach in osteometric sex assessment. Four talus and three patella measurements on dry bone were obtained from 234 individuals of the modern cemetery SIMON Identified Skeletal Collection. The previously derived discriminant functions were applied, accuracies determined, the utility of the different measurements was assessed and new multivariable equations constructed. Accuracies varied between 67% and 86% for talus and 63% and 84% for patella, similar to those reported by the original studies. Multivariable equations should be preferred over equations based on single measurements and combining the most significant measurements rather than using several variables obtained the best possible accuracy. The new discriminant functions did not provide a substantial improvement to the original ones. The overall utility of talus and patella is limited, allowing sex estimation with sufficient certainty only in a small proportion of individuals. Discriminant functions developed in contemporary Greek or Spanish populations are in principle applicable also to Swiss contemporary populations. We recommend that at present existent studies of this type should be validated and tested rather than developing new formulas.

Missing, not Forgotten. The German Association for the Recovery of the Fallen in Eastern Europe (VBGO e.V.).

For almost three decades, the Association for the Recovery of the Fallen in Eastern Europe (Verein zur Bergung Gefallener in Osteuropa e.V., VBGO) has committed itself to the location, recovery, documentation, and identification of the missing victims of World War II. Through the tireless efforts of the VBGO volunteers, over 7.000 fallen soldiers have been recovered and given a proper burial, many of them having been identified. The VBGO's work contributes to the ongoing process of coming to terms with one of the darkest chapters in European history. Countless dead are still missing, but they are not forgotten. The aim of this text is to present the VBGO, its goals and work, and the battlefield of Klessin as the main focus of the VBGO.

Sex estimation of skeletons in middle and late adulthood: reliability of pelvic morphological traits and long bone metrics on an Italian skeletal collection.

There are several metric and morphological methods available for sex estimation of skeletal remains, but their reliability and applicability depend on the sexual dimorphism of the remains as well as on the availability of preserved bones. Some studies showed that age-related changes on bones can cause misclassification of sex. The purpose of this study was to establish the reliability of pelvic morphological traits and metric methods of sex estimation on relatively old individuals from a modern Italian skeletal collection. The data for this study were obtained from 164 individuals of the Milano CAL skeletal collection and average age of the samples was 75 years. In the pelvic morphological method, the recalibrated regression formula of Klales and colleagues (2012), pre-auricular sulcus, and greater sciatic notch morphology were used for sex estimation. With regard to the metric method, 15 standard measurements from upper and lower limbs were analyzed for sexual dimorphism. The results showed that in pelvic morphological approach, the application of regression formula of the revised Klales and colleague formula (2017) resulted in 100% accuracy. Classification rates of metric methods vary from 75.19 to 90.73% with the maximum epiphyseal breadth of proximal tibia representing the most discriminant parameter. This study confirms that the effect of age on sex estimation methods is not substantial, and both metric and morphological methods of sex estimation can be reliably applied to individuals of Italian descent in middle and late adulthood.