Forensic Sci., Volume 2, Issue 3 (September 2022) – 11 articles

Age estimation is a paramount issue in criminal, anthropological, and forensic research. Because of this, several areas of research have focused on the establishment of new approaches for age prediction, including bimolecular and anthropological methods. In recent years, DNA methylation (DNAm) has arisen as one of the hottest topics in the field. Many studies have developed age-prediction models (APMs) based on evaluation of DNAm levels of many genes in different tissue types and using different methodological approaches. However, several challenges and confounder factors should be considered before using methylation levels for age estimation in forensic contexts. To provide in-depth knowledge about DNAm age estimation (DNAm age) and to understand why it is not yet a current tool in forensic laboratories, this review encompasses the literature for the most relevant scientific works published from 2015 to 2021 to address the challenges and future directions in the field. More than 60 papers were considered focusing essentially on studies that developed models for age prediction in several sample types. Full article

The international workshop ‘Forensic Search and Recovery of Clandestine Graves’ took place over two days in 2021 in Wroclaw, Poland. The goal of the workshop was to improve search methods and techniques related to the examination of clandestine burial sites. Geophysical methods were used by an international team of multi-disciplinary specialists to detect simulated burial sites. The training focused on testing methods, including Ground-Penetrating Radar (GPR), to verify the effectiveness of the methods in the search for two features representing clandestine burials. The forensic community in Central European countries, including Poland, has been slow to adopt these technologies due to controversial results. While geophysical research is successfully carried out in archaeological research and forensic contexts internationally, its application in the activities of the prosecutor’s office and the police in Poland has been relatively unsuccessful. This has resulted in several controversies related primarily to the erroneous expectations of how the methods are successfully applied. This may be the result of operator inexperience in applying these methods to the search for clandestine burials. This training paired an experienced GPR operator with law enforcement teams and archaeologists, leading to the successful discovery of simulated burials using GPR. Full article

Objectives: The focus of this research is to evaluate the sex estimation methods on isolated human materials by applying morphological methods published in various forensic and anthropological literature on different skeletal series. Materials and Methods: 165 individuals from the 19th to 20th century Inden skeletal series, 252 individuals from the 13th to 14th century Lübeck skeletal series of German ancestry housed at the Department of Historical Anthropology and Human Ecology, the University of Göttingen, Germany, and 161 individuals from the 19th and 20th century of South African African ancestry housed within the Raymond A. Dart collection of modern human skeletons at the University of Witwatersrand, South Africa, with crania, mandibles, and pelves, were assessed. The evaluation criteria are burial information on the Inden series, genetic sex on both the Inden and the Lübeck series, and previous demography on cadavers from the South African African series. Results and Discussion: The sex estimation with cranial traits perform better in Inden and South Africa samples and worse in Lübeck sample. The mandible accuracies for pooled sexes are not exemplary, but the individual traits perform better for males in the Inden, Lübeck, and South Africa samples, except for gonion and angle, which performs better in females. The pelvic traits perform better in the Inden and South Africa samples compared to the Lübeck sample. The statistical tests show that there is a huge difference in the accuracy rates and the performance between both population groups from Germany itself, considering that Inden and Lübeck samples share the same ancestry. The accuracy rates improve with the exclusion of ambiguous individuals. Full article

Background: In recent years, cross-border migrations have resulted in an increase in the number of unaccompanied children apprehended at the United States border, particularly in the state of California. The assessment of the chronological age of a child, in many instances, determines the type of services rendered within the medico-legal system. Age can be determined by using population-specific reference standards, preferably within a geographical area. However, such standards are not available for Hispanic children living in California. Aim: To present new standards by developing and validating a reference data set for dental age estimation in Hispanic children in California. Methods: For the reference dataset, a total of 705 dental panoramic radiographs of healthy children aged 7.00 to 13.99 years belonging to Hispanic ethnicity in California were obtained from the archives of a teaching hospital. All permanent teeth on the left side were scored in automated software, and the average at assessment was calculated for each stage of dental development. For the validation dataset, 133 radiographs that were not part of the reference dataset were obtained based on the above criteria. The difference between the chronological age (CA) and dental age (DA) estimated using the California Hispanic reference dataset was assessed using a paired t-test with a statistical significance of p < 0.05. Results: The overall difference between the chronological age and dental age (CA-DA) was 0.03 years (1.56 weeks) for females and −0.10 years (−5.26 weeks) for males, and the difference was not statistically significant for children aged 8.00 to 12.99 years (p > 0.05). Conclusions: The newly constructed dental reference data can be recommended for age estimation in children belonging to Hispanic ethnicity in California. Full article

Techniques used in forensic analysis have to find an appropriate balance between fairness to the defendant and efficiency and safety for forensic personnel. Safety issues are particularly acute in analyzing large seizures of bags likely containing heroin, possibly laced with fentanyl. National and local law specifies penalties that depend on the weight of seized powder containing heroin. Local custom makes available to the prosecution and the defense a preliminary report showing the presence of heroin and an indication of the powder weight seized. Such a report, even if it involves uncertainty, can be useful to both parties in understanding the likely sentencing range, with a view toward plea bargaining. An earlier methodological paper demonstrates how data from a sample of bags can be used to create a probability distribution for the weight of seized powder. The aim of this paper is to study whether sampling itself creates substantial additional uncertainty. To this end, we apply the above method to four populations with weights known for each item in the population. We draw eight random samples of size five from each population. Applying the proposed method to each sample, the results show that the variation created by drawing these samples is trivial. We conclude that the proposed method, which is convenient and safer for personnel, can be used without prejudice against the defendant. Full article

Tooth Cementum Annulation (or TCA) is a technique that relies on the analysis of the incremental growth of dental cementum for age and season at death estimation. It has been extensively adopted as a “black box technique”, despite numerous controversies. Its potential in forensics called for this review, which aims to provide the reader with an overarching critical synthesis of what has been done and what is known about the TCA from different perspectives. Results have been divided according to three different themes: human, animal and evolutionary studies, as well as biological studies. The summary and comparison of these show the complexity of this topic, its limits, and how the scientific community can collectively collaborate for improvements. Overall, it is clear that the potential of the TCA is significant in terms of age and season at death estimation and that (as long as its biology is still addressed and researched for) there should not be any reason to not consider this technique as valid as the other anthropological methods adopted for biological profiling. Full article

In densely populated countries like Italy, cremation is promoted for the final disposition of the dead. However, many families still choose inhumation or entombment. In ordinary (traditional) tombs, bodies skeletonize slowly and partially, and often need a second disposal after the exhumation. The aim of this study was to experimentally test the functionality of a new type of tomb, defined as “aerated”. Aerated tombs feature an aerating system, absorbing materials and a purifying filter, which collectively maintain ventilation, process putrefactive fluids and gases and neutralize odors. In an experimental cemetery area with pristine soil, limbs of piglets were wrapped in cotton sheets and were either inhumed, placed in ordinary tombs or placed in aerated tombs. Following exhumation after planned time intervals (1, 3, 6, 9, 12, 18, 24 months), all samples were macro- and microscopically examined. The inhumed samples were completely skeletonized by 9 months after burial, and after 12 months showed initial bioerosion in bone Haversian canals. The traditionally entombed samples developed progressive adipocere formation, whereas the samples disposed in aerated tombs became mummified. Despite this outcome, aerated tombs represent a more energy-effective, environmentally-friendly and economical choice when compared to ordinary tombs. A mummified body is lighter and drier than a body entombed traditionally and, as such, it is easier to exhume and quicker to cremate. Overall, in the absence of alternative burials, aerated tombs are more suitable than ordinary tombs for the final disposition of the dead in cemeteries with limited space. The results of this experiment add to the knowledge of taphonomical processes in temperate climates and urban environments, potentially benefitting the forensic and medico-legal community. Full article

This study provides an overview of victim and offender data, the cause and manner of death, the dismemberment type, the post-dismemberment alteration, and the forensic investigation, for 35 Spanish forensic cases. The main aim of this study was to perform a retrospective analysis of dismemberment and body part alteration in Spain since 1990, in particular relating to burning. The sample was selected from a Spanish national database on criminal records (CENDOJ). Official court records were examined for 96 variables, which were analysed through non-metric multidimensional scaling analysis (nMDS). The results obtained revealed that the number of dismemberment cases between 1990 and 2016 totalled 35 (amounting to a total of 40 bodies) with an incidence of 0.29% of the total number of homicide cases in the database. Most of the aggressors were Spanish adult males, and the victims were adult females of foreign nationality. The most commonly employed tool used to kill and dismember was the knife. A total of 15.00% of the 40 bodies were further altered by fire. It was concluded that dismemberment and other postmortem actions contributed to complicating the forensic investigation and hindering the identification of the deceased. Full article

A toxicology laboratory often receives a high number of samples from cases (autopsies or clinical) that may require the quick delivery of trustworthy, accurate results. Thus, there is a great need for a fast and reliable method that is capable of identifying and determining a large number of drugs and drugs of abuse in biological matrices, and especially in blood. In the present study, we describe the development of a fast and simple gas chromatography–mass spectrometry (GC-MS) method for the determination of 41 drugs and drugs of abuse (DOA) in blood. Sample pre-treatment by alkaline liquid–liquid extraction (LLE) was studied through the utilization of different solvents and solvent-to-sample ratios (v/v), which aimed to achieve a greater extraction efficiency and detection sensitivity with a decreased need for large sample volumes. Butyl acetate with a sample-to-solvent ratio of 4:1 (1 mL blood: 0.25 mL butyl acetate) was the most efficient. The method was validated for all analytes, and the evaluation parameters were within the acceptance criteria. The coefficient of determination (R2) was between 0.9934 and 1, the limits of detection (LODs) ranged between 1 ng/mL and 113 ng/mL, and the limits of quantification (LOQs) were between 4 ng/mL and 375 ng/mL for all analytes. The determinations were accurate (accuracy% from 84% to 114%) and precise (RSD% from 0.66% to 14.8% for low concentrations). Deconvolution Reporting Software (DRS) for GC-MS was optimized and applied for data analysis to enhance the identification potential, thereby avoiding false identifications (false positives) and increased productivity. The NIST Automated Mass Spectral Deconvolution and Identification Software (AMDIS) and the analytical utility Retention Time Lock (RTL) Database Library assisted in data evaluation. The method was applied to 89 postmortem cases (history of mental disorders and use of psychiatric pharmaceuticals) in which diazepam (0.13 to 4.34 μg/mL), citalopram (0.04 to 0.24 μg/mL), alprazolam (0.01 to 0.12 μg/mL), olanzapine (0.009 to 0.083 μg/mL), mirtazapine (0.01 to 0.33 μg/mL), venlafaxine (0.006 to 0.92 μg/mL), haloperidol (0.007 to 0.13 μg/mL), and zolpidem (0.01 to 0.16 μg/mL) were successfully quantitated. Full article

Single-nucleotide polymorphism (SNP) markers have great potential to identify individuals, family relations, biogeographical ancestry, and phenotypic traits. In many forensic situations, DNA mixtures of a victim and an unknown suspect exist. Extracting SNP profiles from suspect’s samples can be used to assist investigation or gather intelligence. Computational tools to determine inclusion/exclusion of a known individual from a mixture exist, but no algorithm for extraction of an unknown SNP profile without a list of suspects is available. Here, we present an advanced haplotype-based HMM algorithm (AH-HA), a novel computational approach for extracting an unknown SNP profile from whole genome sequencing (WGS) of a two-person mixture. AH-HA utilizes techniques similar to the ones used in haplotype phasing. It constructs the inferred genotype as an imperfect mosaic of haplotypes from a reference panel of the target population. It outperforms more simplistic approaches, maintaining high performance through a wide range of sequencing depths (500×–5×). AH-HA can be applied in cases of victim–suspect mixtures and improves the capabilities of the investigating forces. This approach can be extended to more complex mixtures with more donors and less prior information, further motivating the development of SNP-based forensics technologies. Full article