International Journal of Legal Medicine最新文献

Determining the time since death (TSD) is crucial in forensic investigations, yet it remains a complex process influenced by numerous postmortem factors. This study explores RNA degradation as a promising marker for precise TSD estimation, leveraging real-time quantitative polymerase chain reaction to quantify degradation rates. We analysed degradation patterns of messenger RNA (mRNA), ribosomal RNA (rRNA), and microRNA (miRNA) across liver, lung, and heart tissues, focusing on housekeeping genes (GAPDH, ACTB, RPS10, RPS29) and rRNA (5 S, 18 S, 28 S), alongside tissue-specific miRNAs (miR-122, miR-195, miR-200c, miR-1, U6). RNA yield, and purity varied significantly among tissues, with the liver showing higher RNA yields but lower purity compared to the heart and lung. RPS29 and RPS18 emerged as stable reference markers, unlike GAPDH and ACTB, which showed postmortem instability. rRNA demonstrated greater resilience to degradation compared to mRNA, with distinct patterns peaking at 60-84 h postmortem. miRNAs, particularly miR-122, and miR-1, showed potential as TSD biomarkers due to their relative stability. A mathematical model for TSD estimation was developed using 14,400 Ct values from 600 tissues analyzed in R-studio. The model demonstrated high to moderate predictive accuracy across three tissues under controlled environmental conditions. The model achieved the highest accuracy in heart (R² = 0.75), followed by liver (R² = 0.739), with the lowest predictive power observed in lung (R² = 0.57). These findings underscore the effectiveness of RNA degradation profiles, particularly rRNA and microRNAs, in TSD estimation and highlight the importance of integrating multiple tissues and tissue-specific markers for enhanced forensic reliability.

In recent years, several countries have undergone changes in their legal framework, now explicitly allowing the analysis of genetic markers for the purpose of forensic DNA phenotyping (FDP). Consequently, laboratory workflows for the analysis of appearance informative single nucleotide polymorphisms (SNPs) have been established in several laboratories. Currently, the HIrisPlex-S marker panel and webtool are the most widely used set of appearance informative SNP markers and statistical model used for phenotype predictions. However, many different laboratory protocols are employed for SNP genotyping, mostly using either massive parallel sequencing or single base extension technology. For the GEDNAP and TrACE proficiency tests, FDP modules were introduced in 2021 and 2023. These represented the first instances in which identical samples were analyzed by a fairly large number of laboratories, each of them employing their own laboratory-validated protocol. While mostly consistent phenotyping results were obtained, discrepant genotyping results were observed for some of the analyzed HIrisPlex-S-SNPs in BNC2, OCA2, and TYR. By performing a systematic in-silico analysis of commonly used primer sequences and sequencing the flanking regions of target SNPs in the affected samples from the collaborative exercises, we were able to identify primer binding site mutations, amplification of off-target products and overlap of SBE primers as risk factors for (analysis method-dependent) genotyping discrepancies. While the impact on phenotyping results was minor to negligible in all cases reported here, the issues uncovered by this in-depth analysis may provide a basis for improvements towards more consistent results in the future.

Each year, 320 000 people die from occupational injuries. The construction sector is one of the most hazardous sectors, showing a high incidence of workplace fatalities, of which many are caused by traumatic head injuries. In this study, the efficiency of construction helmets has been investigated through an in-depth accident reconstruction of a real-world workplace head trauma, aiming to investigate causation, prevention and liabilities in an ongoing police investigation. The accident was reconstructed with a state-of-the-art subject-specific head model, used to predict the skull fracture and the brain's response to impact. The results of this study show how the skull fracture pattern was predicted with striking resemblance to the real-world fracture and how the locations of high brain strains were predicted in accordance with the victim's brain lesions. The impact scenarios were compared with the hypothetical scenario in which a construction helmet was worn during the impact. The comparison provides evidence to support that a helmet would have prevented the skull fracture, and possibly also life-threatening brain injury. This case study demonstrates how FE reconstructions can help prove causality and liability in fatal head traumas. More importantly, the findings highlight the role of safety helmets in preventing lethal head injuries and their importance in combating the globally high incidence of fatal work-related accidents.

Postmortem interval (PMI) estimation is a pivotal challenge in forensic science, and skeletal muscle protein degradation has emerged as a promising biochemical tool. In this review, we conducted a comprehensive literature search of PubMed for studies published between 2014 and 2024 using keywords related to PMI estimation and protein/proteomics. Of the 287 results retrieved, 81 were available as free full-text articles, and 17 met the inclusion criteria focusing on skeletal muscle protein. The most used techniques were Western blotting, followed by mass spectrometry and immunohistochemistry. Frequently studied proteins included eEF1A2, desmin, GAPDH, α-actinin, vinculin, α-tubulin, and tropomyosin. Although protein degradation in muscle tissue shows significant potential for PMI estimation, relying on a single protein or a small group of proteins is insufficient due to variability introduced by environmental, individual, and species-specific factors. The study highlights the need for long-term, semi-controlled studies using human tissue, as well as further investigation of new candidate biomarkers and the stability of established markers across diverse PMI ranges and conditions. Comparative studies between animal and human data are vital for understanding species differences and ensuring reliable extrapolation. Moving forward, interdisciplinary and methodologically standardized approaches will be critical for integrating protein-based findings into routine forensic practice and achieving a robust, multifactorial method for PMI estimation.

In forensic practice, the removal of soft tissue is sometimes required to allow for a more accurate skeletal analysis. One of the preferred skeletal processing methods is maceration, the softening of tissue by soaking in water. Despite being widely mentioned in forensic literature, there is still a lack of comprehensive data on how and which maceration methods are applied in daily forensic practice, especially as maceration can be carried out by different forensic professionals and in diverse forensic settings. The aim of this study was to review the published literature on forensic use of maceration and conduct an international survey to compare the practices used with those described in the literature, with special attention on the effects on tool marks and material traces analyses on bone. The literature review, conducted on 27 articles that met the study's inclusion criteria, showed that maceration has been a topic of research and methodological development over the years. Warm water maceration and detergent-based methods were recognized as preferred for practical use, even though no maceration method is without limitations. Survey responses from 57 laboratories and institutes from 19 different countries indicated that while most used methods align with literature recommendations, some practices considered aggressive remain in use. Additionally, it was observed that there is a significant lack of standardization, and maceration is often not included in standard operating procedures (SOPs), which can affect the consistency, efficiency and reproducibility of the methods used, which is something that should be addressed in future.

Utilizing the Finite Element Method and the Total HUman Model for Safety model, simulations were conducted of adult subjects landing with both feet on a hard surface from various heights. The biomechanical response was deconstructed using stress analysis, binary logistic regression, and hierarchical clustering based on Jaccard distance. The simulations revealed a stress propagation mechanism and a longitudinal axial distribution of stress concentrations. Fracture risk exhibited two distinct modes: a "stepwise response" in primary load-bearers (e.g., feet, spine) and a "graded response" in secondary structures (e.g., fibular ends). Logistic regression quantified the height-dependent fracture risk for the fibular ends (OR = 1.682), skull (OR = 1.576), and pelvis (OR = 1.236). The hierarchical cluster analysis of injury patterns corresponds to distinct biomechanical phases: the localized injury phase involving local dissipation, the stress propagation phase characterized by axial transmission, and the systemic injury phase marked by comprehensive damage. This study establishes a comprehensive "mechanism-risk-pattern" biomechanical framework that effectively explains the progression of skeletal trauma during falls. This framework provides a powerful tool for hypothesis generation in forensic case analysis. Extensive experimental findings indicate that threshold settings influence model outcomes, making direct quantitative application to case evidence inadvisable before model optimization. The core contribution of this study lies in proposing this interpretive paradigm, which reveals the systemic nature of skeletal injury and provides a structured pathway for deciphering complex trauma.

Forensic entomologists estimate minimum post-mortem intervals (PMI_min) by measuring the development of larvae on decomposing bodies. Entomotoxicology assumes significance when the deceased had ingested drugs, as these may alter insect development and consequently the accuracy of PMI_min estimations. 5F-ADB, ADB-BUTINACA, and MDMB-4en-PINACA are potent synthetic cannabinoid receptor agonists and drugs of abuse, linked to human intoxications and deaths. We investigated the impact of 5F-ADB on the development of Lucilia sericata (Meigen, 1826) (Diptera: Calliphoridae) larvae and developed a method to detect 5F-ADB, ADB-BUTINACA, MDMB-4en-PINACA, and their metabolites in larvae by liquid chromatography-mass spectrometry. Neonate larvae were exposed to 5F-ADB concentrations that reflect those in human post-mortem specimens. At precise intervals, larvae were killed in near-boiling water, dried, and then their size measured, followed by toxicological analysis. ANOVA demonstrated that only time (= age) significantly affected larval length and mass (through growth). Drug concentrations typically found in post-mortem peripheral blood did not significantly affect larval development, suggesting that 5F-ADB in a corpse would not influence PMI_min estimation with L. sericata. 5F-ADB was detected in trace amounts in larvae that were exposed to post-mortem peripheral blood concentrations. Most larvae from higher concentration treatments contained 5F-ADB levels above the limit of detection of 0.25 µg/kg, but not all samples tested positive. Post-feeding larvae mostly did not contain detectable levels of 5F-ADB, and metabolites were found in none of the larval samples. Actively feeding L. sericata larvae from a corpse may thus be useful to qualitatively identify a prior consumption of 5F-ADB by the deceased.

Objectives: Examination of the radius' distal epiphysis by means of low-field MRI in order to find a reliable method to correctly assess majority in both sexes.

Materials & methods: 650 volunteers of German nationality, evenly distributed to groups of 25 per sex and years of proven age in the age bracket of 12-24 years, were examined between 2021 and 2023 in a single center, prospective, cross-sectional setting. A 0.31 T dedicated joint scanner was used, acquiring a proton density-weighted (PDw) sequence in Dixon technique (Dixon) in coronal slice orientation yielding a fat-sensitive water-suppressed (fat-only) and a water-sensitive fat-suppressed (water-only) series. A classification was formulated for assessment and tested against the proven age. The relevant statistics were defined, the intra- and interobserver-agreements were determined, and the differences between the sexes were analyzed.

Results: The minimum age for stage 6 of the classification was found to be 18.42 years in male individuals and 17.25 years in female individuals. A Mann-Whitney-U Test implies significant sex-related differences for stage 3 (p < 0.01) and stage 4 (p < 0.01), but not for stage 2 (p < 0.162), stage 5 (p < 0.193) and stage 6 (p < 0.146). The intra- and interobserver-agreement levels were substantial.

Conclusion: When using the presented setting of a low-field 0.31 T dedicated joint scanner, acquiring PDw Dixon fat-only and water-only series of the radius' distal epiphysis and using the presented classification, majority can be determined in male but not in female individuals of our cohort. Therefore, 0.31 T low-field MRI yields similar opportunities as examinations by means of high-field MRI scanners.

This case report describes a homicide in which the victim sustained fatal blunt force trauma to the head caused by an initially unidentified weapon. In addition to soft tissue injuries to the scalp, the victim also suffered a single depressed fracture on the central calvaria located at the os frontale. During the forensic medical examination, the cause of death was determined to be a combination of exsanguination and craniocerebral trauma. However, it was not possible to clearly identify the weapon used based on the soft tissue and bone injuries. Histological analysis revealed foreign material containing iron within the wounds. In the marks examination, the cracks in the fracture of the external plate of the calvaria were compared with potential tools of the crime. Striking similarities were identified regarding the shape and size of the cracks in the bone and scratch marks in the paint coating of a weight plate of a dumbbell that was recovered at the crime scene. Further material analysis confirmed the presence of black, polyester-based coating particles within the bone fractures, chemically identical to the paint coating of the weight plate. These findings led to the identification of the weight plate as the instrument of injury, a conclusion upheld by the court. This case underscores the critical importance of interdisciplinary collaboration within forensic science. Particularly in this case involving blunt force trauma. By integrating forensic medical and histological examination, micro trace analysis and comparative marks examination, the weight plate could successfully be identified as the weapon used.