Forensic Science International: Reports最新文献

With the increased use of digital devices, forensic document examiners (FDEs) encounter increasing number of dynamic or online signatures during their physical examinations. This shift expands the possibility of examinations and creates new challenges for FDEs. As such, FDEs require new examination skills using data science-based analyses with artificial intelligence and machine-learning techniques. In recent years, automated signature verification has gained significant interest in biometric research and could be useful in forensic investigations. However, the use of complex black-box systems inconveniencing FDEs in explaining the rationale behind their final assessment, especially when dealing with limited signature samples and various types of forged signatures. Therefore, a new forensic method is needed to assist FDEs’ analysis. To tackle these challenges and incorporate lessons learned from biometrics into forensics, this study proposes a novel forensic online signature analysis method. The proposed method uses a single-template strategy based on recent scientific findings in biometrics while updating the strategy for forensic use. This strategy creates a mean-template set from known signature samples that serve as a writer’s signature master pattern. Consequently, FDEs can evaluate intra-writer and inter-item variations using the mean-template set and a questioned signature. Furthermore, to take advantage of recent digital devices, we focused on both on-surface and in-air trajectories of online signatures, which could improve the discriminative power because in-air trajectories are invisible for imposters. Finally, we demonstrate the effectiveness and applicability of the proposed method in a forensic scenario using a public forensic online signature dataset.

Estimating the age-at-death of unidentified human skeletal remains is essential in medico-legal cases. Currently, the pubic symphyseal face and iliac auricular surface provide noteworthy indicators of adult ageing. However, as the pelvis may not always be available in some medico-legal cases, a need exists for substitute methods derived from other skeletal components. This study was conducted to derive a new method of estimating age-at-death using patellar morphology. The study sampled 104 paired patellae of known age-at-death and sex. Each patella was scored based on the severity of bone lipping at the base and the development of auricular marginal osteophytes. A composite scoring system was used to integrate the two scores and produce a representative score for each patella (0, 1, 2, 3). The relationship between patellar morphological changes and age-at-death was evaluated using a Spearman ranked correlation test (rho). Additionally, one-way ANOVA was used to assess age-at-death differences between composite scores. In both sex groups, age-at-death displayed a very strong, positive monotonic relationship with bone lipping (rho = 0.777 in males, rho = 0.752 in females) and auricular marginal osteophytes (rho = 0.622 in males, rho = 0.859 in females). In addition, patellar composite scores showed a stronger age-at-death correlation (rho = 0.888 in females, rho = 0.873 in males, p < 0.001 for each case) when compared to a level that was previously reported on the iliac auricular surface (rho = 0.624 in males, rho = 0.626 in females, p < 0.01 for each case). Statistically significant age-at-death differences were observed between all composite scores (p < 0.001), except between composite scores 2 and 3 (p = 0.967). The current study's findings led to the development of a new scoring method using composite scores based on patellar morphological changes that can support forensic anthropologists in estimating the age-at-death of unidentified human skeletal remains.

Forensic investigation aims to identify, clarify and analyze evidence from a crime scene in order to assist law enforcement agencies. In this regard, both forensic hematology and forensic traumatology are responsible for interpreting the material evidence related to the crime and its nature. One of the biggest challenges in recognizing hemorrhagic diseases at crime scenes is the limited visibility of these diseases in forensic investigations, as well as the scarcity of resources for identification. In light of this context, this study aimed to describe a case of forensic investigation, whose victim had a cut-contusion injury in the head and significant blood loss. Analysis of the evidence demonstrated that the injury was caused by a fall from the victim's own height, hitting the head on the base of the gate rail at their residence. The forensic investigation of blood stain patterns revealed a predominant presence of blood stains caused by accumulation and it was discovered that the victim had a severe form of hemophilia, whose main characteristic is hemorrhage. After the fall, the victim died due to significant blood loss disproportionate to the injury suffered. The presentation of this report aims to provide elements of forensic hematology, which is not widely disseminated in the specialized literature, in order to assist professionals in dealing with similar patterns.

This autopsy case involved a woman in her 60 s with a history of temporal tracheostomy. During an event in which her son allegedly experienced an epileptic seizure, he grasped the woman around the upper chest for several moments. The woman then experienced breathing difficulties, lost consciousness and died. Postmortem computed tomography revealed a pinhole-like tracheal narrowing at the level of the tracheostomy encircled by the thyroid. Autopsy revealed a modestly enlarged thyroid gland due to previously undiagnosed Hashimoto's disease and an old fracture in a tracheal ring indicating that the trachea had been compressed by the thyroid. Hashimoto's disease rarely causes sudden death through systemic endocrine disturbance, but this case may illustrate that against a background of previous tracheostomy that mechanically weakens the trachea, enlargement of the thyroid (goiter) as a local effect of the disease can also cause sudden death.

Driving under the influence (DUI) of alcohol or drugs is a major contributing factor to road traffic crashes. Most countries have implemented legal limits for alcohol, and some countries have also implemented legislation on DUI of drugs, in most cases impairment-based or zero- tolerance legislation. Based on searching PubMed, Google Scholar, and the internet, we identified several jurisdictions that had defined legal limits for drugs in the road traffic legislation. This included ten European countries, seven US states, Canada, and New Zealand. Most of these jurisdictions have defined low limits corresponding to the “lower effect limits” proposed by the European DRUID Project, and four countries have also defined higher, graded sanction limits, for some drugs. There were large variations between jurisdictions.

Short tandem repeat (STR) markers are commonly used in forensic investigations and kinship testing due to their cost-effectiveness and high discriminatory power. In the United Kingdom, STR allele frequency databases are available for different population groups, including the White group, which includes individuals of both English and Irish ethnicity. However, considering differences in historical migrations and influences between England and Ireland, distinct genetic differences might exist between these populations. This study aimed to generate allele frequency data for English and Irish populations using the VeriFiler Express PCR Amplification Kit, which contains loci utilised in national databases. Buccal swabs were collected from 577 English and 500 Irish volunteers with self-proclaimed English and Irish ethnicity respectively. DNA profiling and statistical analyses were performed to assess allele frequencies and forensic parameters, and to perform population comparisons. The results showed minimal genetic differentiation (F_st = 0.0013) between the English and Irish populations. Comparison with other European populations revealed close genetic relationships between the English population and Scandinavian countries, while the Irish population displayed closer genetic links to Western European countries. These findings support historical influences such as Viking migrations and highlight the need for further research using additional markers to explore the genetic makeup and history of the English and Irish populations. Although a single allele frequency database may be suitable due to the observed genetic similarity, the establishment of separate databases should be considered to ensure maximum population representation.

Manual analysis of hand radiographs for sex estimation is prone to biases and errors. This study addresses the need for automated methods by exploring the potential of Convolutional Neural Networks (CNNs) to accurately identify individual sex from Thai hand radiographs, overcoming limitations in data availability and variable quality. To improve dataset quality, we applied contrast limited adaptive histogram equalization (CLAHE) and Gaussian blur filter techniques to Thai hand radiographs from 385 male and 788 female individuals. We split these images into training, validation, and test sets. We also applied image augmentation techniques to increase the number of radiographs in the training dataset. Seven CNN models were trained, validated, and evaluated on 100 unseen male and female radiographs each. Among these models, the InceptionResNetV2 architecture demonstrated superior performance, achieving an accuracy of 87.50 % and an F1-Score of 86.91 %. Notably, this model utilized information from the 2nd to the 5th metacarpal bone and proximal phalanges in males, and from the 2nd metacarpal bone in females. Our findings provide a solid foundation for sex estimation from Thai hand radiographs, highlighting the power of CNNs in mitigating challenges associated with data quantity and quality. By automating the sex estimation process using CNNs, forensic analysis can benefit from enhanced accuracy and objectivity, enabling faster and more reliable sex assessment. We envisage that future research will build upon these findings to further improve the performance of sex estimation, contributing to advancements in forensic analysis and facilitating more effective utilization of Thai hand radiographs for sex estimation.

This study analyzed the differences in the decomposition patterns and post mortem intervals of hanged and surface carcasses using domestic pigs as human analogs. Six domestic pigs weighing between 25 kg and 30 kg were separated into two groups comprising three pigs each. Three pigs were hanged on the branches of trees at the research facility; whereas the other three pigs were placed on the soil surface. Daily periodic decomposition observations were noted and scored for a period of 30 days alongside the accumulated degree days. There is a statistically significant (P = 0.001) difference in the decomposition between hanged and surface pigs. The hanged pigs decomposed faster at the initial stage reaching a total body score (TBS) of 10 by the second day but gradually slowed down and mummified; whereas the surface pigs initially decomposed at a slower rate but later sped up at about 167 ADD till complete skeletonization. ADD and TBS are very reliable and accurate predictors for PMI estimation of surface and hanged pig carcasses. Insect colonization of a carcass is a very important factor that determines the rate of decomposition of hanged and surface pig carcasses in Okuku, Nigeria. There is a statistically significant difference in the decomposition rate and pattern of hanged and surface pig carcasses. The prediction models for estimating PMI considered ADD and TBS as variables, and these prediction models are very reliable at 95 % confidence level.

Research on how to reliably reconstruct the shape of the ear for facial approximations is limited, especially in countries such as South Africa where standard ear casts are still used in manual methods. To improve objectivity, computer aided methods are being developed for facial approximations – which require extensive population specific datasets for facial feature morphology. This study aims to assess variations in the shape of the ear and the underlying external auditory meatus (EAM) through the analysis of cone-beam computed tomography (CBCT) scans of 40 black South Africans (males n = 17; females n = 23) and 76 white South Africans (males n = 29; females n = 47) between the ages of 18 and 90 years. Shape data was collected by placing 19 capulometric landmarks on the 3D reconstructions of the ear and 46 sliding craniometric landmarks along the EAM. Geometric morphometric analysis revealed highly significant variation in ear shape between groups for population affinity (p-value = 0.001), while sex and age were only significant between the white South Africans (p-value < 0.05). Only population affinity significantly influenced shape in the EAM (p-value = 0.001), and both the ear and EAM showed significant levels of symmetry (p-value = 0.007). While an ear will never be exactly recreated, basing facial estimates on the decedent’s biological profile can lead towards the highest possible accuracies. For the ear shape specifically, sex and age will not be a priority when creating predictive models, but population affinity will greatly influence the output.