The search process: Integrating the investigation and identification of missing and unidentified persons.

The effective search for the missing and identification of persons, alive or dead, are core components in the prevention and in resolving the issue of Missing Persons. Despite the growing literature on this topic, there is still a lack of publications describing the Search as a process that includes different phases inherently composed of forensic investigative and identification principles for both living and deceased missing persons. This paper is the result of discussions between the Forensic Unit of the International Committee of the Red Cross (ICRC) and members of its external Forensic Advisory Board. It aims to present the Search process as an overarching concept that includes the investigation and identification phases of the missing in any state (dead or alive), in any scenario (with or without bodies), with an integrated, multidisciplinary, and multiagency approach for implementation by all actors involved in the investigation and identification phases of missing persons.

How low can we go? A skeletal maturity threshold for probabilistic visual sex estimation from immature human os coxae.

OBJECTIVES: The appearance of sexually dimorphic traits varies depending on the type of bone, age, environmental and genetic factors and is closely linked to skeletal maturation sequence. Subadult sex estimation currently shows inconsistent accuracy and methods do not incorporate indicators of maturation. The goal of this study is to apply the Santos et al. (2019) adult sex estimation method on virtually reconstructed subadult os coxae and account for pelvic maturation. MATERIAL AND METHODS: The right os coxae of 194 female and male individuals aged 11-30 years from Marseille, France were virtually reconstructed from computed tomography (CT) scans. Santos et al.'s (2019) 11 traits were scored as female, male, or indeterminate. Maturation of 10 pelvic epiphyseal sites was scored using a four-stage system (0-3) to obtain a composite maturity score from 1 to 30. RESULTS: Three maturity groups were identified based on composite maturity scores ranging from 0 to 30. Individuals with a composite maturity score of 15 or higher showed 98 % sex estimation accuracy and a 6 % indeterminate rate. Scores of 2 for the ischiatic tuberosity or 1 for the anterior superior iliac spine can be used as proxies for a composite maturity score of 15 and application on incomplete bones. DISCUSSION: Sexual dimorphism was observed in the epiphyseal maturation sequence and the development of sexually dimorphic pelvic traits. The Santos et al. (2019) method is applicable on immature individuals who meet a maturation threshold with comparable accuracy to adults, without relying on known or estimated age.

International Committee of the Red Cross (ICRC): Cemetery planning, preparation and management during COVID-19: A quick guide to proper documentation and disposition of the dead.

Based on its forensic capacity and experience gained worldwide from the management of the dead in emergencies, including epidemics, the International Committee of the Red Cross has been asked by the authorities and other relevant stakeholders in some of its operational contexts to advise on the planning, preparation and management of cemeteries during COVID19. The management of the dead process includes proper documentation and appropriate disposition, including temporary burials. If there is a sudden and significant increase in the number of deaths, local capacities can quickly become overwhelmed. This guidance, prepared for the COVID19 pandemic, can be applied to any incident involving mass fatalities when the local capacity to provide safe, appropriate and dignified burials is overwhelmed. Specifications on size, spacing, excavation depths, and information about other important considerations are provided. In addition, it provides recommendations on how to correctly map graves while ensuring the traceability and correct management of bodies in a cemetery. Procedures for receiving bodies, as well as measures to ensure the health and safety of relatives and cemetery staff are also covered in this guidance.

Complex mortuary dynamics in the Upper Paleolithic of the decorated Grotte de Cussac, France.

The Mid-Upper Paleolithic (Gravettian) karstic Grotte de Cussac (France) contains two areas of human remains in the context of abundant (and spectacular) parietal engravings. The first area (loci 1 and 2) includes the skeleton of a young adult male in a bear nest, rearranged by postdecomposition inundation, and the variably fragmentary remains of at least two individuals distributed across two bear nests, sorted anatomically and with most of the elements constrained to one side of one nest. The second area (locus 3) retains remains of two adults and an adolescent, in upper hollows and variably distributed down the slope, largely segregated into upper versus lower body groups. The only decoration associated with the human remains is red pigment on some of the bones or underlying sediment. The human remains indicate variable nonnatural deposition and manipulation of human bodies, body portions, and skeletal elements of at least six individuals. Moreover, Cussac is unusual in the association of these remains with exceptional parietal art. The complex Cussac mortuary pattern joins growing evidence from other Gravettian sites of variable treatment of individuals after death, within and across sites, in terms of formal deposition of the body versus postmortem manipulation versus surface abandonment. It provides a window onto the social diversity and the complex interactions of the living and the dead among these successful Late Pleistocene foragers.

International Committee of the Red Cross (ICRC): General guidance for the management of the dead related to COVID-19.

Based on its forensic capacity and experience gained worldwide from the management of the dead in emergencies, including epidemics, the International Committee of the Red Cross has been asked by the authorities and other relevant stakeholders in some of its operational contexts to advise on the management of the dead from COVID-19 infection, for which it has prepared the following guidance. This includes advice on the handling of COVID-19 fatalities and a set of considerations for managers faced with the need to plan for adequately responding to a possible surge in fatalities caused by COVID-19.

A method of sexing the human os coxae based on logistic regressions and Bruzek's nonmetric traits.

OBJECTIVES: This study aims at proposing a visual method for sexing the human os coxae based on a statistical approach, using a scoring system of traits described by Bruzek (2002). This method is evaluated on a meta-population sample, where the data were acquired by direct observation of dry bones as well as computed tomography (CT) scans. A comparison with the original Bruzek's (2002) method is performed. MATERIALS AND METHODS: Five hundred and ninety two ossa coxae of modern humans are included in the reference dataset. Two other samples, composed respectively of 518 ossa coxae and 99 CT-scan images, are both used for validation purposes. The individuals come from five European or North American population samples. Eleven trichotomic traits (expressing female, male, or intermediate forms) were observed on each os coxae. The new approach employs statistical processing based on logistic regressions. An R package freely available online, PELVIS, implements both methods. RESULTS: Both methods provide highly reliable sex estimates. The new statistical method has a slightly better accuracy rate (99.2%) than the former method (98.2%) but has also a higher rate of indeterminate individuals (12.9% vs. 3% for complete bones). CONCLUSION: The efficiency of both methods is compared. Low error rates were preferred over high ability of reaching the classification threshold. The impact of lateralization and the asymmetry of observed traits are discussed. Finally, it is shown that this visual method of sex estimation is reliable and easy to use through the graphical user interface of the R package.

An overview of the latest developments in facial imaging.

Facial imaging is a term used to describe methods that use facial images to assist or facilitate human identification. This pertains to two craniofacial identification procedures that use skulls and faces-facial approximation and photographic superimposition-as well as face-only methods for age progression/regression, the construction of facial graphics from eyewitness memory (including composites and artistic sketches), facial depiction, face mapping and newly emerging methods of molecular photofitting. Given the breadth of these facial imaging techniques, it is not surprising that a broad array of subject-matter experts participate in and/or contribute to the formulation and implementation of these methods (including forensic odontologists, forensic artists, police officers, electrical engineers, anatomists, geneticists, medical image specialists, psychologists, computer graphic programmers and software developers). As they are concerned with the physical characteristics of humans, each of these facial imaging areas also falls in the domain of physical anthropology, although not all of them have been traditionally regarded as such. This too offers useful opportunities to adapt established methods in one domain to others more traditionally held to be disciplines within physical anthropology (e.g. facial approximation, craniofacial superimposition and face photo-comparison). It is important to note that most facial imaging methods are not currently used for identification but serve to assist authorities in narrowing or directing investigations such that other, more potent, methods of identification can be used (e.g. DNA). Few, if any, facial imaging approaches can be considered honed end-stage scientific methods, with major opportunities for physical anthropologists to make meaningful contributions. Some facial imaging methods have considerably stronger scientific underpinnings than others (e.g. facial approximation versus face mapping), some currently lie entirely within the artistic sphere (facial depiction), and yet others are so aspirational that realistic capacity to obtain their aims has strongly been questioned despite highly advanced technical approaches (molecular photofitting). All this makes for a broad-ranging, dynamic and energetic field that is in a constant state of flux. This manuscript provides a theoretical snapshot of the purposes of these methods, the state of science as it pertains to them, and their latest research developments.

Landmark Typology in Applied Morphometrics Studies: What's the Point?

Landmarks are the hallmark of biological shape analysis as discrete anatomical points of correspondence. Various systems have been developed for their classification. In the most widely used system, developed by Bookstein in the 1990s, landmarks are divided into three distinct types based on their anatomical locations and biological significance. As Bookstein and others have argued that different landmark types possess different qualities, e.g., that Type 3 landmarks contain deficient information about shape variation and are less reliably measured, researchers began using landmark types as justification for selecting or avoiding particular landmarks for measurement or analysis. Here, we demonstrate considerable variation in landmark classifications among 17 studies using geometric morphometrics (GM), due to disagreement in the application of both Bookstein's landmark typology and individual landmark definitions. A review of the literature furthermore shows little correlation between landmark type and measurement reproducibility, especially when factors such as differences in measurement tools (calipers, digitizer, or computer software) and data sources (dry crania, 3D models, or 2D images) are considered. Although landmark typology is valuable when teaching biological shape analysis, we find that employing it in research design introduces confusion without providing useful information. Instead, researchers should choose landmark configurations based on their ability to test specific research hypotheses, and research papers should include justifications of landmark choices along with landmark definitions, details on landmark collection methods, and appropriate interobserver and intraobserver analyses. Hence, while the landmarks themselves are crucial for GM, we argue that their typology is of little use in applied studies. Anat Rec, 302:1144-1153, 2019. © 2018 Wiley Periodicals, Inc.

Facial approximation of Tycho Brahe's partial skull based on estimated data with TIVMI-AFA3D.

The virtual approach in physical and forensic anthropology is increasingly used to further analyze human remains, but also to propose new didactic means for visualization and dissemination of scientific results. Computerized facial approximation (FA) offers an alternative to manual methods, but usually requires a complete facial skeleton to allow for the estimation of the facial appearance of an individual. This paper presents the case of Tycho Brahe, Danish astronomer born during the XVIth century, whose remains were reanalyzed at the occasion of a short exhumation in 2010. Cranial remains of Brahe were poorly preserved, with only a partial facial skeleton, and virtual anthropology tools were used to estimate the missing parts of his skull. This 3D restoration was followed by a FA using TIVMI-AFA3D, subsequently textured with graphic tools. The result provided an interesting estimate that was compared with portraits of the astronomer. The impact of the missing data estimation was investigated by performing FAs on 10 complete test subjects and the same 10 subjects after cropping and estimating 50% of the landmarks (reproducing the preservation state of Tycho Brahe's cranial remains). The comparison between the FA based on the complete and incomplete skulls of the same subject produced a visual assessment of the estimation impact on FAs which is relatively low. This procedure is an alternative to manual methods and offers a reproducible estimate of a face based on incomplete cranial remains. Although the case report concerns a historical individual, the robust automatic estimation of missing landmarks followed by a FA has value for forensic caseworks as a support to the identification process.

Virtual reconstruction of the Upper Palaeolithic skull from Zlatý Kun, Czech Republic: Sex assessment and morphological affinity.

The incomplete cranium discovered at the Zlatý kun site in the Bohemian Karst is a rare piece of skeletal evidence of human presence in Central Europe during the Late Glacial period. The relative position of cranial fragments was restored and missing parts of the cranium were virtually reconstructed using mirroring and the Thin-plate splines algorithm. The reconstruction allowed us to collect principal cranial measurements, revise a previous unfounded sex assignment and explore the specimen's morphological affinity. Visual assessment could not reliably provide a sexual diagnosis, as such methods have been developed on modern populations. Using a population-specific approach developed on cranial measurements collected from the literature on reliably sexed European Upper Palaeolithic specimens, linear discriminant analysis confirmed previous assignment to the female sex. However, caution is necessary with regard to the fact that it was assessed from the skull. The Zlatý kun specimen clearly falls within the range of Upper Palaeolithic craniometric variation. Despite the shift in cranial variation that accompanied the Last Glacial Maximum (LGM), the Zlatý kun skull exhibits a morphological affinity with the pre-LGM population. Several interpretations are proposed with regard to the complex population processes that occurred after the LGM in Europe.

A Large-Sample Test of a Semi-Automated Clavicle Search Engine to Assist Skeletal Identification by Radiograph Comparison.

In 2014, a morphometric capability to search chest radiograph databases by quantified clavicle shape was published to assist skeletal identification. Here, we extend the validation tests conducted by increasing the search universe 18-fold, from 409 to 7361 individuals to determine whether there is any associated decrease in performance under these more challenging circumstances. The number of trials and analysts were also increased, respectively, from 17 to 30 skeletons, and two to four examiners. Elliptical Fourier analysis was conducted on clavicles from each skeleton by each analyst (shadowgrams trimmed from scratch in every instance) and compared to the search universe. Correctly matching individuals were found in shortlists of 10% of the sample 70% of the time. This rate is similar to, although slightly lower than, rates previously found for much smaller samples (80%). Accuracy and reliability are thereby maintained, even when the comparison system is challenged by much larger search universes.

Facial Soft Tissue Depth Measurement: Validation of the 75-Shormax.

The shorth and 75-shormax were recently posited as an improved alternative to the arithmetic mean for describing facial soft tissue thicknesses in craniofacial identification. The shorth better estimates the data peak, while the 75-shormax provides improved provisions for a long right tail. When first proposed, the 75-shormax was subjectively gauged. Herein, shormax errors are calculated at every whole percentile to quantitatively determine zones of error minimization in two large samples: (a) CT data of French adults, n-range = 211-469 individuals; and (b) all C-Table data, n-range = 60-1065 individuals [including part but not all of sample (a)]. The smallest residuals were found at the 79th percentile (mean of raw residuals) and the 74th percentile (mean of absolute residuals). The 75-shormax is subsequently verified as good error minimizer since the absolute differences carry the greatest weight and the 74th percentile closely approximates the 75th percentile.

Impact of secular trends on sex assessment evaluated through femoral dimensions of the Czech population.

Human skeletal variability is influenced by several factors, including genetics, environment, and socio-cultural background. Forensic methods being traditionally based on targeted reference groups, it is recognized that they are population-specific. Additionally, secular trends highly impact on the skeletal morphology, but the effect of outdated methods on forensic cases is not yet well documented. This paper compares the sexual dimorphism of femoral dimensions in two samples from the Czech population separated by 60 years in time (Pachner and the Prague National Museum Collections). Significant secular trends are present within this short span in both sexes and for most of the seven tested linear variables. The consequence of secular trends on sex determination is tested with logistic regression, and a decrease in reliability is systematically observed when using the older Czech sample on the 20th century sample, whichever the set of variables included. A model based on a recent Croatian sample provides a higher reliability on contemporaneous Czech individuals. These results imply that above population specificity, temporal consistency may be a major criterion to fulfil when applying forensic anthropology identification methods.

Human Identification via Lateral Patella Radiographs: A Validation Study.

This research examines the utility of patella outline shape for matching 3D scans of patellae to knee radiographs using elliptical Fourier analysis and subjective methods of human visual comparison of patellae across radiographs for identification purposes. Repeat radiographs were captured of cadaver's knees for visual comparison before patellae were extracted and skeletonized for quantitative comparisons. Quantitative methods provided significant narrowing down of the candidate pool to just a few potential matches (<5% of original sample), while the human analysts showed high capacity for correctly matching radiographs, irrespective of educational level (positive predictive value = 99.8%). The successful computerized matching based on a single quantified patella trait (outline shape) helps explain the potency achieved by subjective visual examination. This work adds to a growing body of studies demonstrating the value of single isolated infracranial bones for human identification via radiographic comparison.

Statistical sex determination from craniometrics: Comparison of linear discriminant analysis, logistic regression, and support vector machines.

Accuracy of identification tools in forensic anthropology primarily rely upon the variations inherent in the data upon which they are built. Sex determination methods based on craniometrics are widely used and known to be specific to several factors (e.g. sample distribution, population, age, secular trends, measurement technique, etc.). The goal of this study is to discuss the potential variations linked to the statistical treatment of the data. Traditional craniometrics of four samples extracted from documented osteological collections (from Portugal, France, the U.S.A., and Thailand) were used to test three different classification methods: linear discriminant analysis (LDA), logistic regression (LR), and support vector machines (SVM). The Portuguese sample was set as a training model on which the other samples were applied in order to assess the validity and reliability of the different models. The tests were performed using different parameters: some included the selection of the best predictors; some included a strict decision threshold (sex assessed only if the related posterior probability was high, including the notion of indeterminate result); and some used an unbalanced sex-ratio. Results indicated that LR tends to perform slightly better than the other techniques and offers a better selection of predictors. Also, the use of a decision threshold (i.e. p>0.95) is essential to ensure an acceptable reliability of sex determination methods based on craniometrics. Although the Portuguese, French, and American samples share a similar sexual dimorphism, application of Western models on the Thai sample (that displayed a lower degree of dimorphism) was unsuccessful.

Anthropological facial approximation in three dimensions (AFA3D): computer-assisted estimation of the facial morphology using geometric morphometrics.

This study presents Anthropological Facial Approximation in Three Dimensions (AFA3D), a new computerized method for estimating face shape based on computed tomography (CT) scans of 500 French individuals. Facial soft tissue depths are estimated based on age, sex, corpulence, and craniometrics, and projected using reference planes to obtain the global facial appearance. Position and shape of the eyes, nose, mouth, and ears are inferred from cranial landmarks through geometric morphometrics. The 100 estimated cutaneous landmarks are then used to warp a generic face to the target facial approximation. A validation by re-sampling on a subsample demonstrated an average accuracy of c. 4 mm for the overall face. The resulting approximation is an objective probable facial shape, but is also synthetic (i.e., without texture), and therefore needs to be enhanced artistically prior to its use in forensic cases. AFA3D, integrated in the TIVMI software, is available freely for further testing.

Morphometric comparison of clavicle outlines from 3D bone scans and 2D chest radiographs: a shortlisting tool to assist radiographic identification of human skeletons.

This paper describes a computerized clavicle identification system primarily designed to resolve the identities of unaccounted-for U.S. soldiers who fought in the Korean War. Elliptical Fourier analysis is used to quantify the clavicle outline shape from skeletons and postero-anterior antemortem chest radiographs to rank individuals in terms of metric distance. Similar to leading fingerprint identification systems, shortlists of the top matching candidates are extracted for subsequent human visual assessment. Two independent tests of the computerized system using 17 field-recovered skeletons and 409 chest radiographs demonstrate that true-positive matches are captured within the top 5% of the sample 75% of the time. These results are outstanding given the eroded state of some field-recovered skeletons and the faintness of the 1950's photofluorographs. These methods enhance the capability to resolve several hundred cold cases for which little circumstantial information exists and current DNA and dental record technologies cannot be applied.

Quantification of perspective-induced shape change of clavicles at radiography and 3D scanning to assist human identification.

Change in perspective between antemortem and postmortem imaging sessions (radiograph to radiograph and surface scan to radiograph) may cause different 2D renderings of the same osseous element complicating comparisons for identification. In this study, clavicle shape changes due to radiographic positioning and 3D laser scanning were examined in 20 right-side specimens, as pertinent to chest radiograph comparisons. Results indicate substantial changes in clavicle form with short source-to-image receptor distance, elevation of the element from the image receptor, and movement of the element away from the center beam (10% mean square for shape). Although quantitative shape differences were small when the clavicle was in close opposition to the image receptor (3% mean square), important qualitative differences remained with large distances from the center beam (e.g., conoid tubercle presence/absence). The significance of these results for image superimposition and computer-automated-shape-based searches of radiographic libraries to find matching candidates is discussed.

Facial soft tissue depths in French adults: variability, specificity and estimation.

Facial soft tissue depths (FSTD) are used in facial approximation to render the shape of the face, and are traditionally published specifically to population, corpulence, and sex amongst other factors. This paper investigates the variability of FSTD collected at 37 landmarks on 500 CT (computed tomography) scans of French living individuals. The specificity of the sample is evaluated by comparing values with six published datasets of various populations and recording techniques. Apart from a significant influence of the corpulence, FSTD show negligible variations with age and sex. The differences between the French sample and other datasets contradict the hypothesis of major influence of population, and underline sample specificity linked with technique and methodology of data measurement. Regression equations were computed to estimate FSTD using age, sex, facial build, and craniometrics, leading to more accurate results if such factors are known. Nevertheless, application of the pooled T-table (Tallied-Facial-Soft-Tissue-Depth-Data) has been validated according to the French sample.