Fingering a Murderer: A Successful Anthropological and Radiological Collaboration*

Abstract: We illustrate an interdisciplinary approach to identify a victim in a case with complex taphonomic and procedural issues. Burning, fragmentation, species commingling, and examination by multiple experts required anthropological preparation and analysis combined with radiographic adaptations to image and match trabecular patterns in unusually small, burned specimens. A missing person was last seen in the company of a reclusive female on a remote rural property. A warranted search found several burn sites containing human and animal bones. Fragment preparation, analysis, and development of a biological profile by anthropologists enabled examination by the odontologist, molecular biologist, and radiologist, and justified use of antemortem radiographs from one potential victim. Visual and radiological comparison resulted in a positive (later confirmed) identification of the victim by radiological matches of three carpal phalanges. Although some dimensional changes are expected with burning, morphological details were preserved, aided by selection of relatively intact, small bones for comparison.     

Anthropological Measurement of the Juvenile Clavicle Using Multi‐Detector Computed Tomography—Affirming Reliability

Currently, there is no standardized protocol for multi‐detector computed tomography (MDCT) measurement of juvenile remains. Using 33 juvenile clavicles, this paper investigates a protocol to allow MDCT measurements, comparable or supplemental with traditional osteometric measurements, to be acquired for application to previously published algorithms. The results illustrate that there is no significant difference between MDCT measurements and those taken by direct osteometric methods. By presenting such a protocol, this paper takes the first steps toward validation of the process of conversion from measurement of dry juvenile bone to MDCT compatibility and allows the forensic world to take a step forward in standardizing the way MDCT is used for forensic practice. This paper assesses the limitations and potential applications of this virtual approach and offers some suggestions for where further work might progress the conversion of these new approaches into legally admissible anthropological techniques of age estimation.     

The role of mobile computed tomography in mass fatality incidents

Mobile multi-detector computed tomography (MDCT) scanners are potentially available to temporary mortuaries and can be operational within 20 min of arrival. We describe, to our knowledge, the first use of mobile MDCT for a mass fatality incident. A mobile MDCT scanner attended the disaster mortuary after a five vehicle road traffic incident. Five out of six bodies were successfully imaged by MDCT in c. 15 min per body. Subsequent full radiological analysis took c. 1 h per case. The results were compared to the autopsy examinations. We discuss the advantages and disadvantages of imaging with mobile MDCT in relation to mass fatality work, illustrating the body pathway process, and its role in the identification of the pathology, personal effects, and health and safety hazards. We propose that the adoption of a single modality of mobile MDCT could replace the current use of multiple radiological sources within a mass fatality mortuary.     

Identification of a Carbonized Body Using Implanted Surgical Plates: The Importance of Computed Tomography

In addition to clinical examination, forensic odontologists can use diagnostic imaging as an auxiliary method for identification. This paper reports a case where forensic odontologists from the Afrânio Peixoto Legal Medicine Institute in Rio de Janeiro (Brazil) positively identified a carbonized and partially calcined body using oral and maxillofacial imaging. The cadaver showed several metallic plates fixed with metallic screws on bones of the neurocranium and viscerocranium. Family members provided spiral computed tomography scans of the skull and a panoramic radiograph that were acquired after an accident that required surgical procedures. Comparative analysis between the clinical exam and the maxillofacial images demonstrated complete coincidence, confirming the victim's identity. Dactyloscopy, which is the most commonly used method of identification, was not possible because of the body carbonization. Thus, diagnostic imaging, especially computed tomography, was essential for elucidation of this case.     

Stature Estimation from Postmortem CT Femoral Maximum Length in Contemporary Danish Population

Stature estimation methods for Danish adult population have generally relied on Trotter and Gleser’s and Boldsen’s regression equations that are based on the skeletal remains of recent war dead American Whites, Terry Skeletal Collection, and Danish archaeological medieval skeletal materials, respectively. These equations are probably not suitable for stature estimation in contemporary Danish forensic cases. Furthermore, because postmortem computed tomography (PMCT) is now routinely performed at Danish forensic departments, equations based on PMCT, rather than measurements of defleshed bones, are needed. The aim of this study was to develop new equations for adult stature estimation based on PMCT femoral measurement. Maximum femoral length was measured on the PMCT images of 78 individuals (41 males and 37 females) aged 23–45 years. The measurement accuracy was tested on dry bones, and all the measurements were included in the inter- and intra-observer analyses. Both analyses results demonstrated the reliability of the method and data. Comparison between the living stature of the individuals and the estimates based on the equations by Trotter and Gleser and Boldsen demonstrated the unreliability of the previous equations to some extent. New regression equations were then developed and validated on a different sample of 18 Danish forensic cases. Comparisons of all the equations indicated that both the sets of previous equations underestimated the stature in the new validation dataset. The new equations developed in this study provide a reliable alternative for stature estimation in modern Danish forensic cases.     

Veldt fires in South Africa: Implications on osteometry and the biological profile

Standard operating procedures for forensic anthropological analyses dictate that thermally altered remains should not be measured, hindering the creation of a biological profile. Few studies have addressed estimating biological parameters from burned remains, with the greatest focus of this research area being on cremated remains. However, veldt fires are more common than cremation in the South African forensic context. The aim of this study was to explore the degree of structural changes observed in domestic pig (Sus scrofa) bones associated with thermal destruction and the potential impact on the estimation of a biological profile using standard osteometric methods. A total of 96 pig femora were divided equally into two categories: fresh and dry. Within each category, equal samples were exposed to different durations of burning, namely, 5, 10, and 20 min. Ten standard femoral anthropological measurements were collected before and after burning. Technical error of measurement and Wilcoxon signed-rank tests were used to assess changes in the femoral dimensions before and after burning. Most measurements were significantly different after burning, with the fresh bones decreasing in size by up to 7.8% and the dry bones decreasing in size by up to 4.0%. The magnitude of post-burning measurement changes for both burn conditions was similar to, or smaller than has previously been reported for observer measurement errors of commonly used variables investigated for standard osteometric studies. Veldt fires are less intense than cremation, thus causing less shrinkage.     

Radiological, forensic, and anthropological studies of a concrete block containing bones

Multidisciplinary forensic, anthropological, and radiological studies of bone fragments encased in a concrete block were carried out to determine whether or not the bones were human. Multislice computed tomography (MSCT) investigation was performed before the bones were removed from the concrete. MSCT study pinpointed the location of the bone fragments within the concrete block, which was helpful for their extraction and recovery, and identified most of their types and nature. Osteological study on dry bones provided more accurate identification of the bones and of their side. According to both methods, the human skeletal remains were compatible with those of a child, aged 8-13 years old, with a minimum height of 128 cm. Neither investigation identified sex or racial phenotype. Both studies identified the skeletal remains as consisting of two animal and five human bones. Furthermore, both methods revealed that the concrete completely encased bones, suggesting a secondary burial.     

Bilateral First Rib Anomalous Articulations with Pseudarthroses Mimicking Healing Fractures in an Infant with Abusive Head Injury

Bilateral symmetric bone nodules were observed in the anterolateral first ribs of an infant with shaking injuries at autopsy. The location prompted diagnostic considerations of healing fractures versus anomalous articulations with pseudarthroses. The forensic pathologist worked with forensic anthropologists and pediatric radiologists to evaluate autopsy findings and compare premortem and postmortem X‐rays. Gross examination of the bones by the pathologist and anthropologists confirmed bilateral, callus‐like bone nodules in first‐rib locations associated with pseudarthroses. Histologic examination of one of the bones further showed features most consistent with pseudarthrosis, not a healing fracture. Radiologists then compared multiple premortem and postmortem radiographs that showed no remodeling of the bone over a 2‐week interval between the time of injury and death, which would be unexpected for a healing fracture in an infant. This multidisciplinary approach resulted in the appropriate diagnosis of pseudarthroses due to anomalous articulations, an uncommon finding in forensic pathology.     

Discriminant function analysis for sex assessment in pelvic girdle bones: sample from the contemporary Mexican population

Sex assessment of skeletal remains plays an important role in forensic anthropology. The pelvic bones are the most studied part of the postcranial skeleton for the assessment of sex. It is evident that a population-specific approach improves rates of accuracy within the group. The present study proposes a discriminant function method for the sex assessment of skeletal remains from a contemporary Mexican population. A total of 146 adult human pelvic bones (61 females and 85 males) from the skeletal series pertaining to the National Autonomous University of Mexico were evaluated. Twenty-four direct metrical parameters of coxal and sacral bones were measured and subsequently, sides and sex differences were evaluated, applying a stepwise discriminant function analysis. Coxal and sacra functions achieved accuracies of 99% and 87%, respectively. These analyses follow a population-specific approach; nevertheless, we consider that our results are applicable to any other Hispanic samples for purposes of forensic human identification.     

Estimating the Temperature of Heat‐exposed Bone via Machine Learning Analysis of SCI Color Values: A Pilot Study

Determining maximum heating temperatures of burnt bones is a long‐standing problem in forensic science and archaeology. In this pilot study, controlled experiments were used to heat 14 fleshed and defleshed pig vertebrae (wet bones) and archaeological human vertebrae (dry bones) to temperatures of 400, 600, 800, and 1000°C. Specular component included (SCI) color values were recorded from the bone surfaces with a Konica‐Minolta cm‐2600d spectrophotometer. These color values were regressed onto heating temperature, using both a traditional linear model and the k‐nearest neighbor (k‐NN) machine‐learning algorithm. Mean absolute errors (MAE) were computed for 1000 rounds of temperature prediction. With the k‐NN approach, the median MAE prediction errors were 41.6°C for the entire sample, and 20.9°C for the subsample of wet bones. These results indicate that spectrophotometric color measurements combined with machine learning methods can be a viable tool for estimating bone heating temperature.     

Stature estimation based on dimensions of the bony pelvis and proximal femur

Pelin et al. recently showed that sacral height measured on lateral magnetic resonance images can be used with moderate accuracy to reconstruct stature in males. In most forensic anthropological cases, however, sacral dimensions must be obtained from dry bones. In this study, the relationship between stature and sacral height, hip height, and femur head diameter measured on dry bone was evaluated for American Blacks and Whites of both sexes (n = 247). There are significant correlation between stature and these three dimensions, but the results suggest that none of the dimensions predict stature with the accuracy needed to be useful in forensic anthropological investigations.     

Post-mortem forensic neuroimaging: correlation of MSCT and MRI findings with autopsy results

Multislice-computed tomography (MSCT) and magnetic resonance imaging (MRI) are increasingly used for forensic purposes. Based on broad experience in clinical neuroimaging, post-mortem MSCT and MRI were performed in 57 forensic cases with the goal to evaluate the radiological methods concerning their usability for forensic head and brain examination. An experienced clinical radiologist evaluated the imaging data. The results were compared to the autopsy findings that served as the gold standard with regard to common forensic neurotrauma findings such as skull fractures, soft tissue lesions of the scalp, various forms of intracranial hemorrhage or signs of increased brain pressure. The sensitivity of the imaging methods ranged from 100% (e.g., heat-induced alterations, intracranial gas) to zero (e.g., mediobasal impression marks as a sign of increased brain pressure, plaques jaunes). The agreement between MRI and CT was 69%. The radiological methods prevalently failed in the detection of lesions smaller than 3mm of size, whereas they were generally satisfactory concerning the evaluation of intracranial hemorrhage. Due to its advanced 2D and 3D post-processing possibilities, CT in particular possessed certain advantages in comparison with autopsy with regard to forensic reconstruction. MRI showed forensically relevant findings not seen during autopsy in several cases. The partly limited sensitivity of imaging that was observed in this retrospective study was based on several factors: besides general technical limitations it became apparent that clinical radiologists require a sound basic forensic background in order to detect specific signs. Focused teaching sessions will be essential to improve the outcome in future examinations. On the other hand, the autopsy protocols should be further standardized to allow an exact comparison of imaging and autopsy data. In consideration of these facts, MRI and CT have the power to play an important role in future forensic neuropathological examination.     

数字X线测量上肢长骨推算身高

目的应用数字X线测量上肢长骨,建立适合当代中国四川汉族人群长骨推算身高的回归方程。方法按纳入标准对365例四川汉族正常人进行身高测量及上肢的数字X线检查,测量上肢各长骨不同标志点之间的长度,用SPSS统计软件对各测量值与身高进行相关回归分析,并对回归方程进行回代检验。结果共建立27个一元回归方程以及3个多元回归方程,各方程都具有统计学意义。上肢长骨中,尺骨相关性大于桡骨,男性相关性大于女性,多元回归方程的准确性高于一元回归方程。结论放射学方法测量长骨推算身高是一项简单、实用的方法,更适合上肢尸块的个人识别,值得进一步研究。     

Skeletal height reconstruction from measurements of the skull in indigenous South Africans

Stature reconstruction is important as it provides a forensic anthropological estimate of the height of a person in the living state; playing a vital role in the identification of individuals from their skeletal remains. Regression formulae for stature estimation have been generated for indigenous South Africans based on measurements of long bones of upper and lower extremities and the calcaneus. Since these bones are not always available for forensic analysis, it became necessary to use other bones such as the skull for stature estimation. The aim of the present study was to investigate the usefulness of certain measurements of the skull of indigenous South Africans in the estimation of adult stature. Ninety-nine complete skeletons obtained from the Raymond A. Dart Collection, School of Anatomical Sciences of the University of the Witwatersrand, were used. Total skeletal height (TSH) was calculated for each skeleton using the Fully's (anatomical) method. Furthermore, six variables were measured on each skull. TSH was regressed onto these cranial measurements in order to obtain regression formulae. The correlation coefficients obtained ranged between 0.40 and 0.54. The range of the standard errors of estimate from the current study (4.37 and 6.24) is high in comparison to that obtained for stature estimation based on intact long bones and the calcaneus. Therefore, the equations presented in this study should be used with caution in forensic cases when only the skull is available for human identification.     

Cognitive bias in forensic anthropology: Visual assessment of skeletal remains is susceptible to confirmation bias

An experimental study was designed to examine cognitive biases within forensic anthropological non-metric methods in assessing sex, ancestry and age at death. To investigate examiner interpretation, forty-one non-novice participants were semi randomly divided into three groups. Prior to conducting the assessment of the skeletal remains, two of the groups were given different extraneous contextual information regarding the sex, ancestry and age at death of the individual. The third group acted as a control group with no extraneous contextual information. The experiment was designed to investigate if the interpretation and conclusions of the skeletal remains would differ amongst participants within the three groups, and to assess whether the examiners would confirm or disagree with the given extraneous context when establishing a biological profile. The results revealed a significant biasing effect within the three groups, demonstrating a strong confirmation bias in the assessment of sex, ancestry and age at death. In assessment of sex, 31% of the participants in the control group concluded that the skeleton remains were male. In contrast, in the group that received contextual information that the remains were male, 72% concluded that the remains were male, and in the participant group where the context was that the remains were of a female, 0% of the participants concluded that the remains were male. Comparable results showing bias were found in assessing ancestry and age at death. These data demonstrate that cognitive bias can impact forensic anthropological non-metric methods on skeletal remains and affects the interpretation and conclusions of the forensic scientists. This empirical study is a step in establishing an evidence base approach for dealing with cognitive issues in forensic anthropological assessments, so as to enhance this valuable forensic science discipline.     

Image-guided virtual autopsy findings of gunshot victims performed with multi-slice computed tomography and magnetic resonance imaging and subsequent correlation between radiology and autopsy findings

Because the use of radiology in modern forensic medicine has been, until today, mostly restricted to conventional X-rays, which reduces a 3D body to a 2D projection, a detailed 3D documentation of a gunshot's wound ballistic effects was not possible. The aim of our study was to evaluate whether the progress in imaging techniques over the last years has made it possible to establish an observer-independent and reproducible forensic assessment using multi-slice computed tomography (MSCT) and magnetic resonance imaging (MRI) technologies for the documentation and analysis of gunshot wounds. The bodies of eight gunshot victims were scanned by MSCT and by MRI; the data of these imaging techniques were post-processed on a workstation, interpreted and subsequently correlated with the findings of classical autopsy. With the spiral CT and MRI examinations and the subsequent 2D multi-planar reformation (MPR) and 3D shaded surface display (SSD) reconstruction, the entire gunshot-created complex skull fractures and brain injuries (such as wound channels and deeply-driven bone splinters) could be documented in complete and graphic detail. CT and MRI also documented vital reaction to the gunshot by demonstrating air emboli in the heart and blood vessels and the classic pattern of blood aspiration to the lung. Gunshot residues deposited within and under the skin were visible. In conclusion, we think that the radiological methods of MSCT and MRI have the potential to become a routine "virtual autopsy" tool in the future. Bullets and relevant histological samples from specific sites then might be won in image-guided minimally invasive fashion via percutaneous biopsy. The rapid application of developing radiological methods may lead to new horizons in forensic documentation and intravital as well as postmortem examination.     

The Power of Contextual Effects in Forensic Anthropology: A Study of Biasability in the Visual Interpretations of Trauma Analysis on Skeletal Remains

The potential for contextual information to bias assessments in the forensic sciences has been demonstrated, in several forensic disiplines. In this paper, biasability potential within forensic anthropology was examined by analyzing the effects of external manipulations on judgments and decision‐making in visual trauma assessment. Three separate websites were created containing fourteen identical images. Participants were randomly assigned to one website. Each website provided different contextual information, to assess variation of interpretation of the same images between contexts. The results indicated a higher scoring of trauma identification responses for the Mass grave context. Furthermore, a significant biasing effect was detected in the interpretation of four images. Less experienced participants were more likely to indicate presence of trauma. This research demonstrates bias impact in forensic anthropological trauma assessments and highlights the importance of recognizing and limiting cognitive vulnerabilities that forensic anthropologists might bring to the analysis.     

Charred body: virtual autopsy with multi-slice computed tomography and magnetic resonance imaging

The correct examination of a charred body is a forensic challenge. Examination, interpretation, and conclusion in respect to identification, vital reactions, toxicological analysis, and determining cause and manner of death are all more difficult than without burns. To evaluate what can be seen in the case of a charred body, we made an examination with the new radiological modalities of cross-section techniques, via multi-slice Computed Tomography (MSCT) and Magnetic Resonance Imaging (MRI), prior to performing the classical forensic autopsy. In a charred body case of a single motor vehicle/fixed object collision with a post crash fire, the radiological methods of MSCT and MRI made it possible to document the injuries caused by burn as well as the forensic relevant vital reactions (air embolism and blood aspiration). In conclusion, we think postmortem imaging is a good forensic visualization tool with a great potential for the forensic documentation and examination of charred bodies.     

The Role of Forensic Anthropology in the Examination of the Daegu Subway Disaster (2003, Korea)*

Abstract: Meticulous recovery of victims in the Daegu subway disaster was possible, because charred and fragmented victims were left in situ. Because bodies were piled one over another within the train, appropriate methodology during the recovery was critical to identifying the victims. The disaster area was thoroughly documented with notes, photographs, and schematic drawings of the various locations. The recovery team, comprising two medical examiners and one forensic anthropologist, decided when charred body parts and cremated bones were linked to the same individual based on the anatomy and forensic anthropological examination. Without these recovery procedures, it would not have been possible to efficiently harvest representative DNA sample from most of the victims’ body parts. After the entire process of identification, 136 victims were positively identified, and six victims remained unidentified. This study supports the crucial role of forensic anthropologists in the recovery of victims, especially in fire scenes.