International Journal of Legal Medicine最新文献

Vertebral artery injuries (VAIs) are rarely observed in forensic practice and can result from either penetrating injuries or blunt force trauma to the neck. The identification of such injuries represents a pivotal challenge for forensic pathologists, due to the protected anatomical course of these vessels, particularly in their extracranial tract. Over the years, several approaches have been proposed to address this issue, including vessel gross examination through different dissection techniques, the water injection method and, more recently, post-mortem computed tomography angiography (PMCTA), which is currently deemed the gold standard approach. However, no studies have employed contrast-enhanced radiological techniques using an ex-situ approach to investigate VAIs.The aim of this study is to investigate the diagnostic potential of fluoroscopy and contrast-enhanced micro-CT in detecting extracranial vertebral artery lesions via an ex-situ approach. Cervical blocks (C1-C3) from three forensic cases of neck stab wounds were collected, and fluoroscopy and contrast-enhanced micro-CT, using Barium Sulfate and Diatrizoate Sodium as contrast agents respectively, were performed. The above radiological techniques proved accurate and reliable in identifying vascular injuries, exhibiting enhanced diagnostic performance compared to conventional macroscopic examination. Fluoroscopy provides dynamic imaging, enabling real-time detection of contrast leakages, while contrast-enhanced micro-CT allows simultaneous assessment of both vascular injuries and bone fractures. Therefore, these promising techniques could serve as complementary tools to conventional diagnostic approaches, offering an accurate and comprehensive characterization of the cervical injury pattern in cases of fatal penetrating neck trauma.

In forensic casework, unraveling the criminal nature of an event requires not only identifying the individual source of specific biological stains but also confirming their cellular origin. Recent studies have demonstrated the feasibility of identifying body fluids using specific mRNA markers and linking body fluids to their donors via coding region SNPs (cSNPs) within these mRNAs. Nanopore sequencing enables the detection of more cSNPs within longer mRNA amplicons due to its long-read capability. In this proof-of-principle study, we developed a targeted mRNA nanopore sequencing panel to simultaneously infer body fluid sources and identify individuals. This panel includes 12 body fluid-specific mRNAs and two reference genes (RGs), with a total of 41 cSNPs included in these 14 mRNA transcripts. Sequencing data showed that specific mRNAs were highly expressed in peripheral blood, semen, and menstrual blood, with an average read proportion exceeding 95% (excluding RGs reads). Cross-reactivity was observed in saliva and vaginal secretions, but all body fluid samples could still be accurately clustered. Alternative alleles were detected for 16 cSNPs, and genotyping results for randomly selected samples were validated for consistency with Sanger sequencing. The system demonstrated discriminatory power (DP) ranging from 0.5645 to 0.9017, providing information about the body fluid donor. However, further research is needed to identify more specific mRNAs, introduce additional highly polymorphic cSNPs, and perform evaluations on larger populations.

[Abstract] Short tandem repeat (STR) loci within the human genome are extensively utilized in forensic DNA analysis because of their high level of polymorphism. At present, the combined DNA index system (CODIS) STRs are the principal ones adopted in the majority of general-purpose forensic kits. Moreover, non-CODIS STRs can serve as valuable supplementary tools for resolving complex paternity cases, conducting evolutionary studies, and performing population genetics analyses. Along with non-CODIS STRs, unusual DNA profiles have been consistently identified, as observed with CODIS STRs. In this present study, we investigated the allelic distribution and population genetics parameters of the D21S2055 locus in a cohort of 258 unrelated individuals from Fujian Province, China. The locus exhibited significant genetic diversity, with twenty-one distinct alleles, mostly spanning a size range from 16.1 to 38. Notably, a large off-ladder allele, 57.2, which was also included in the findings. The core repeat sequence of this allele was found to be [CTAT]₂CTAA[CTAT]₁₃[TATC]₃TAT[TATC]₁₄. TACTATCTCTATAT[TATC]₃TAT[TATC]₁₄[TATC]₂. The population genetic parameters, including the power of discrimination (PD), probability of paternity exclusion (PE) and polymorphic information content (PIC), were calculated as 0.9687, 0.7388, and 0.8576, respectively. In conclusion, it is essential to conduct population genetic analysis before applying non-CODIS STRs in forensic applications. Special emphasis should be placed on large off-ladder alleles that may extend beyond the designated locus region or overlap with an adjacent locus.

Kinship verification using biometric traits is crucial for finding missing children, rapid forensic identification, and social media analysis. Ear biometrics is gaining attention due to its uniqueness, permanence, and non-intrusiveness. However, current research on ear-based kinship verification is limited, and the factors associated with ear similarities across kinship-related individuals require to be evaluated. To fill this gap, our study developed deep learning models to quantify the similarity between ear images and conduct the kinship verification task. Two ear image datasets, namely SCED and CNKE, were collected from Chinese subjects. The SimiNet model, which utilized a pre-trained ResNet50 as its backbone, was constructed to evaluate the cosine similarity between ear image pairs. For kinship verification, the VTrans model was established by combining a pre-trained VGG16 with Transformer modules. Based on the cosine similarity, the SimiNet model obtained 93.53% accuracy and an AUC (Area Under the Curve) of 0.98 for personal verification. The similarity analysis further revealed that kinship-related individuals of the same sex displayed higher ear similarity scores. The VTrans model attained 71.17% accuracy and an AUC of 0.76 on the CNKE dataset. Heatmaps revealed that the VTrans model focused on the helix and the upper half of the ear during kinship verification. The model code has been provided in Github ( https://anonymous.4open.science/r/SimNet_VTrans-EB41 ) to facilitate refinement in future research. Our study has successfully established deep learning models for ear similarity quantification and kinship verification, providing effective tools for biometric forensic identification.

Paternity testing is a well-established application of forensic genetics, generally providing accurate results based on inheritance laws. However, in rare cases, genetic anomalies may arise, complicating the interpretation of DNA profiles and requiring careful evaluation. In this study, we describe a paternity case involving a rare tri-allelic pattern observed at the CSF1PO locus. To confirm the anomaly, genetic material from multiple family members was analysed using different kits. The pattern was consistently verified across all amplification attempts, demonstrating its reliability and its concordance with a specific individual. This case emphasises the importance of careful interpretation in genetic testing and considers the potential implications of such anomalies for DNA analysis. Furthermore, it calls for collaboration among forensic disciplines and experts to address similar findings in forensic and medical genetics.

Carrion decomposition is an important component of the ecosystem and plays a significant ecological role in the food chain. During decomposition, arthropods and microorganisms help to decompose and recycle organic matter and nutrients. Although research has been conducted on microorganisms and arthropods associated with carrion across different biogeoclimatic ecoregions, no study has identified these communities from carrion placed under a tropical rainforest. Therefore, this study aims to investigate the arthropod, bacterial, and fungal communities associated with Sus scrofa Linnaeus. carrion placed in a tropical rainforest in Malaysia. Adult flies and maggots and other arthropods were collected during the forensic entomological survey. The specimens collected were killed, separated, preserved in 70% ethanol, and identified using a stereomicroscope in the laboratory. Swab samples were collected from the skin, anal, and oral cavity of the wild boar carrion. Both bacterial and fungal communities were identified using Sanger sequencing. Data on temperature and humidity were recorded with a data logger throughout the four-day experiment. The results demonstrated that the most isolated bacteria were those of uncultured_bacteria, Ignatzschineria sp. and Gram-negative bacteria, especially Acinetobacter sp., during the early stages of decomposition. Furthermore, the consistent presence of Ascomycota fungi, particularly Exophiala sp., Yarrowia sp., and Meyerozyma sp., suggests their unique occurrence specifically in the tropical rainforest. A total of 219 adult flies and about 9,200 larvae were collected from a wild boar carcass over three days, with Chrysomya pinguis and Chrysomya villeneuvi being the main species, and the latter displaying notable predatory behaviour. These results present for the first time the dominant arthropods, bacteria and fungi inhabiting the carrion in one of the oldest rainforests in the world. (Keyword: Carrion, decomposition, bacteria, fungi, arthropods, tropical rainforest, Malaysia).

The estimation of fracture age is important for both clinical and forensic purposes. The objective of this systematic review is to identify the imaging modalities currently used in clinical and forensic practice for fracture ageing, with a view to appraise technologies used, patient demographics studied in research, and the healing stages and criteria defined to estimate time since injury. After conducting a bibliographic literature search, we identified 21 suitable publications for inclusion in the review. Comparison of the literature for fracture ageing found that most research has used 2D radiography, predominantly using an antemortem paediatric population. The remaining publications used MRI, CT, histology, and macroscopy. Although the most frequent number of radiographic stages assessed was six, no two methods assessed the same combination of features. Indeed, variation in the number and definition of healing stages rendered comparison between the publications challenging. Consequently, limited work has been carried out to validate existing methods of ageing. The results therefore reiterate the need for caution in the use of radiographic modalities for forensic fracture ageing. Histology remains the undisputed gold standard, however it is a destructive and exclusively postmortem method. As such, there is need for further research to investigate the potential of additional imaging modalities such as micro-CT, with a high-resolution, 3D, and non-destructive nature. This can serve as a valuable complement to help support and navigate the challenges associated with traditional histopathological methods.

Methadone is a widely used opioid agonist in maintenance therapy for opioid addiction; however, its global diversion is increasing. Determining methadone's role in drug-related deaths is often challenging due to its pharmacological properties, such as tolerance, and the co-consumption of psychotropic substances. This study aims to identify the demographic, clinical, and therapeutic characteristics of methadone-related deaths to support forensic interpretation. A systematic literature review was conducted to retrieve and analyze publications on methadone-related deaths that included post-mortem toxicological analyses. The data were integrated with methadone-related death cases examined at the Institute of Forensic Medicine in Bologna. The literature review identified 58 articles for data extraction. Aggregated data were available in 29 papers, while individual-level data were reported in 30 studies (with one paper providing both). The aggregated data comprised 3,148 cases, with a median of 80 cases per study (interquartile range, IQR 32-129). A total of 240 individual cases were retrieved from the literature (n = 204) and Bologna's Forensic Medicine records (n = 36). Among these, 27 were children, 190 were adults, and 23 had no reported age. The median blood methadone concentration was 300 ng/mL (IQR 195-600 ng/mL) in children and 503 ng/mL (IQR 300-933 ng/mL) in adults, overlapping with levels observed in living patients undergoing methadone maintenance therapy. Statistically significant differences in methadone blood concentrations were found between deaths attributed solely to methadone and those involving multidrug intoxication, with higher concentrations observed in the former group (p < 0.001). This review confirms previous findings on the overlap between therapeutic and toxic methadone blood concentrations, highlighting the increasing risk of multidrug intoxications. The extensive number of cases collected and reviewed serves as a valuable resource to assists forensic pathologists in interpreting post-mortem methadone concentrations in relation to the cause of death.