International Journal of Legal Medicine最新文献

In this paper, we present a forensic perspective on classifying gunshot wound patterns using Deep Learning (DL). Although DL has revolutionized various medical specialties, such as automating tasks like medical image classification, its applications in forensic contexts have been limited despite the inherently visual nature of the field. This study investigates the application of DL techniques (59 architectures) to classify gunshot wounds in a forensic context, focusing on distinguishing between entry and exit wounds and determining the Medical-Legal Shooting Distance (MLSD), which classifies wounds as contact, close range, or distant, based on digital images from real crime scene cases. A comprehensive database was constructed with 2,551 images, including 1,883 entries and 668 exit wounds. The ResNet152 architecture demonstrated superior performance in both entry and exit wound classification and MLSD categorization. For the first task, achieved accuracy of 86.90% and an AUC of 82.09%. For MLSD, the ResNet152 showed an accuracy of 92.48% and AUC up to 94.36%, though sample imbalance affected the metrics. Our findings underscore the challenges of standardizing wound images due to varying capture conditions but reflect the practical realities of forensic work. This research highlights the significant potential of DL in enhancing forensic pathology practices, advocating for Artificial Intelligence (AI) as a supportive tool to complement human expertise in forensic investigations.

The so-called "shedder status", which can more precisely be referred to as "individual shedding propensity" (ISP), has been the subject of forensic genetic research for more than two decades. Numerous studies have been published on this topic many of which report contradictory and/or insufficiently documented results regarding the existence, influencing factors, classifications of and test methodologies for the ISP of skin material. To date, there is no scientific consensus on the best way to register and conceptualize this variable, that is essential for the assessment of DNA transfer events. Here, we present the results of a systematic review and meta-analysis to give an account of the current state of research on the ISP (including data up to end of December 2023). To this end, 50 publications on the topic of "shedder status" were systematically surveyed and the combined data was statistically analysed regarding the comprehensibility and test methodology for determining the ISP as well as key influencing factors (including sex and age) and classifications. Despite difficulties in the analysis due to missing or incomplete information in individual publications, the following insights and recommendations are established, also considering current dermatological and histological research: the tendency to shed (mostly) skin material upon physical contact with surfaces is a genuine and meaningfully ascertainable, person-specific i.e. individual variable, which is apparently influenced by male sex and young age. In contrast, time since handwashing and the choice of hand do not appear to have any relevant influence. When testing an individual's tendency to deposit DNA containing material, it is preferable to set a standardised contact time and use plastic tubes as the contact surface or perform direct skin abrasion. The body region from which the sample is taken also appears to be relevant. Overall, however, the results confirm the difficulty to compare and interpret the results from many available studies, and we advocate to harmonise and standardise study designs and experiments and to apply a quality control before publishing such data.

Introduction: Age estimation in forensic science plays a crucial role in determining legal and criminal responsibilities for living individuals. When the age of an individual is uncertain, a forensic age estimation examination is required, typically involving radiographic evaluation of bone and dental development. This study aimed to estimate and classify bone and dental ages in a Portuguese population aged 6 to 21 years, using the Baccetti and Moorrees, Fanning, and Hunt methods. The results were compared to chronological age and between methods for medico-legal purposes, utilizing lateral cephalograms and orthopantomograms.

Materials and methods: A total of 466 lateral cephalograms and 767 orthopantomograms were analyzed. Baccetti stages were assigned to the lateral cephalograms, and cephalometric analysis was performed using ImageJ® software. For orthopantomograms, each tooth in the third quadrant was assigned a stage based on the MFH method.

Results and discussion: Cohen's weighted kappa coefficients were 0.987 (intra-observer) and 0.977 (inter-observer) for the Baccetti method. Moorrees, Fanning, and Hunt method validations ranged from 0.655 to 1.00. Correlation coefficients for dental and bone regressions were 0.894 and 0.907, with adjusted determination coefficients of 0.798 and 0.822, respectively. The dental regression underestimated age, unlike the bone regression. The methods' accuracy and reliability varied based on the age being classified.

Conclusions: Both regressions accurately estimated age, but the dental method was more appropriate due to its tendency to underestimate, high precision and consistency of results. No significant differences were found between males and females, and both methods, dental and bone, may be used together to classify legal ages.

Adverse drug reactions and fatalities can result from therapeutic drug use due to genetic deficiencies in drug-metabolizing enzymes. In cases where ancillary testing may not reveal a clear cause of death, molecular autopsies can be valuable. However, forensic mortuaries do not retain DNA samples in all cases, which hinders subsequent genetic testing if it is later deemed necessary. This study aimed to evaluate whether post-mortem whole blood samples collected for toxicological analysis, could provide viable DNA for genetic testing after varying storage periods. Thirty deceased individuals were recruited with informed consent. Blood collected at autopsy from each individual was stored in two sodium fluoride/potassium oxalate (gray-top) tubes, two additive-free (red-top) tubes and one ethylenediaminetetraacetic acid (EDTA; purple-top) tube- the latter recommended for DNA analysis. Blood from one gray-top and one red-top tube were sampled for toxicological analysis prior to DNA analysis, while the remaining samples (acting as controls) underwent DNA analysis immediately. DNA analysis involved DNA extraction and DNA concentration and degradation assessment. Blood samples were stored at 4 °C and DNA extraction and analysis was repeated one year and then five years later. Toxicological sampling did not significantly influence DNA results. DNA concentration and quality significantly decreased over time for all sample types, with DNA from red-top tubes showing the greatest decline. The study showed that DNA testing for drug-metabolizing enzymes was feasible on whole blood that had been stored for five years. This finding supports the potential for retrospective genetic testing in cases of adverse drug reactions and fatalities.

It is imperative in a forensic investigation to determine the identity of an unidentified corpse, for which a crucial starting point is to establish population affinity as part of the biological profile supplied by the forensic anthropologist. The present study investigates the feasibility of using multidetector computed tomography (MDCT) images to quantify craniometric variation between Japanese and Malay populations relative to the estimation of population affinity in a forensic context. The Japanese and Malay samples comprise MDCT scans of 252 (122 female; 130 male) and 182 (84 female; 98 male) adult individuals, respectively. A total of 18 measurements were acquired, and two machine learning methods (random forest modeling, RFM; support vector machine, SVM) were applied to classify population affinity. The accuracy of the two-way pooled-sex model was 88.0% for RFM and 94.5% for SVM, respectively. The four-way population and sex model produced an overall classification accuracy of 81.3% for RFM and 91.7% for SVM. The sex-specific models of population affinity showed correct rates of classification of more than 90% in both females (90.8% for RFM and 97.6% for SVM) and males (91.2% for RFM and 97.4% for SVM). Our findings clearly indicate that the cranial measurements acquired in MDCT images can be used for the forensic classification of Japanese and Malay individuals and thus serve as a reference for forensic anthropologists attempting to identify unidentified remains.

Analysing genetic material from skeletonised human remains has become valuable in forensic and archaeological contexts. While the petrous bone is often preferred for DNA extraction, its availability is not guaranteed, and because of destructive sampling, it is not frequently used in forensic cases. This study explores the potential of patellae as an alternative source of bone material for genetic investigations. Forty-five patellae were sampled from a post-World War II mass grave and an archaeological Christian cemetery dated from the 13th to 19th centuries. A full demineralisation extraction method was used to obtain the DNA, and real-time PCR quantification was used to determine the quantity and quality of DNA. To evaluate the suitability of patellae for forensic and archaeological analyses, short tandem repeat (STR) typing was performed using the ESI17 Fast PCR amplification kit (Promega). To explore the difference in DNA yield, DNA degradation and STR typing success between the post-World War II and archaeological patellae, statistical analysis was performed. The results revealed significantly higher DNA yield and STR typing success in WWII patellae and higher degradation of DNA in archaeological patellae, highlighting the impact of environmental exposure time on genetic material preservation. Almost all WWII patellae achieved a high success rate in STR typing with full profiles generated. More than half of the archaeological patellae showed high STR typing performance and highly informative partial profiles were obtained, indicating the suitability of patellae not only for forensic purposes but also for archaeological genetic analyses.

Introduction: This study aimed to assess students' knowledge, awareness, and attitudes regarding forensic-medicine concepts taught during a Medicine and Surgery degree program at eight Italian universities. Additionally, the study aimed to evaluate the impact of the course on students' knowledge and attitudes toward choosing medical residency.

Materials and methods: A cross-sectional study was conducted through an anonymous web-based survey of medical students at eight italian universities. Descriptive, univariate, and logistic regression analyses were performed for the selected questions.

Results: The survey was completed by 1022 students. Forensic medicine appears to be important for providing training in the fundamental concepts of forensic medicine, especially professional liability, defensive medicine, and forensic pathology. The descriptive and univariate analyses demonstrate that the course can assist students in choosing their specialisation school. The multivariate analysis highlighted the impact of the forensic medicine course on orienting students' choice of medical residency, increasing it by nine times after attending the course. In the logistic regression analysis of the influence of medical liability on the choice of medical residency, students recognised a doubled effect after attending the course. Finally, the perceived usefulness of the course was significantly higher after attendance.

Conclusions: Forensic medicine courses have the task of defining the duties and responsibilities of forensic physicians, providing indispensable tools for future medical practitioners regardless of their future specialisation, and limiting the increasing use of defensive medicine. In conclusion, it is imperative for governments to implement measures directed at diminishing the risk of burnout arising from the ongoing pressure associated with the fear of medicolegal litigation, encompassing both criminal and civil contexts.

In forensic practice, identifying the species of unknown bodily fluid stains can provide assistance in the qualitative analysis and investigation of cases, and vaginal fluid stains, as one of the common bodily fluid stains, are most commonly seen at the scene of sexual assault. At present, the commonly used vaginal peptidase or microscopic detection methods currently have drawbacks such as high false negative rates, poor sensitivity, and high requirements for sample integrity and background color. However, in forensic investigations, the test materials have specificity and scarcity, making it difficult to ensure their quantity and quality. Thus, in order to achieve rapid and sensitive detection of vaginal fluid stains, in this study, we combined nested PCR and isothermal amplification technology to construct a rapid detection system for suspicious vaginal fluid stains using lateral flow dipstick. This system achieves detection by detecting the specific marker microbial community Lactobacillus crispatus in vaginal fluid, and has a high sensitivity and accuracy, which can achieve detection at template quantities as low as 2.31 copies. More importantly, the system can achieve detection at a constant temperature of 37 °C without the need for complex instruments. It can provide rapid and sensitive identification results, providing assistance for subsequent forensic material extraction and individual identification.

Forensic taphonomy is the study of postmortem changes of human remains for the purpose of answering legal investigative questions. Many variables can affect the pattern and rate of decomposition of remains, posing challenges for taphonomic studies and estimation of the postmortem interval. Given the gap in knowledge regarding the suitability of using frozen remains to extrapolate conclusions to fresh material, investigating the effects of freeze-thaw cycles followed by burial on human remains is vital for forensic practice and taphonomic research. This study explored the impact of a freeze-thaw cycle and subsequent burial on human tissue decomposition under semi-controlled field conditions. Fresh and fresh-frozen-thawed hands were buried at the Amsterdam Research Initiative for Sub-surface Taphonomy and Anthropology for 31.7 to 340.4 accumulated degree days. Decomposition was assessed using fluorescence measurements targeting protein and fluorescent oxidation products, and broader excitation-emission matrix measurements in skin, adipose, and muscle tissue. Decomposition trends varied primarily by treatment group: fresh samples generally aligned with expectations that protein levels would decrease over time while fluorescent oxidation products increased, whereas fresh-frozen samples deviated significantly from these expectations. Significant differences were found between protein and fluorescent oxidation products levels of fresh and fresh-frozen tissue at corresponding time points, indicating this method's potential in determining sample state. However, fluorophore peak monitoring in excitation-emission matrices did not prove useful in establishing decomposition trends or potentially distinguishing between sample states. Despite limitations inherent to pilot and human taphonomy studies, this study clearly demonstrates that differences exist in the decomposition of fresh and fresh-frozen tissue, and that these trends vary slightly by tissue type. We therefore conclude that frozen material cannot be considered a proper substitute for fresh tissue regarding taphonomic processes, and the methods used in this study show promise in being used to differentiate between pre-decomposition treatments.

Alcohol consumption is widespread in most western countries such as Germany and a relevant risk factor for morbidity and mortality. Sensitive detection of alcohol consumption using suitable markers is therefore of central importance for clinical and forensic diagnostics. Direct alcohol markers are non-oxidative products of ethanol, which are produced in the body during the degradation of ethanol and provide high sensitivity and specificity. Phosphatidylethanol (PEth) is a promising marker for detecting alcohol consumption in the past days to weeks. The aim of this study was to determine the minimum amount of ethanol for a single alcohol consumption that leads to a detectable increase in blood PEth concentration. Therefore, 12 participants were recruited and, after four weeks of abstinence, drinking tests were carried out with target blood alcohol concentrations (BAC) of 0.6 g/kg and 0.75 g/kg. The PEth samples were obtained as dried-blood spots on the test day and the three following days and analyzed using LC-MS/MS. The result of the study were a detectable increase of PEth in the blood above limit of detection after both drinking events in all participants and an increase in PEth above the cutoff concentration for abstinence of 20 ng/mL in 9/12 (75%) and 7/12 (58%) participants, respectively, from a minimum BAC of 0.48 g/kg. These results make PEth appear promising as a marker for controlled moderate alcohol consumption.