International Journal of Legal Medicine最新文献

In Chinese criminal law, the ages of 12, 14, 16, and 18 years old play a significant role in the determination of criminal responsibility. In this study, we developed an epiphyseal grading system based on magnetic resonance image (MRI) of the hand and wrist for the Chinese Han population and explored the feasibility of employing deep learning techniques for bone age assessment based on MRI of the hand and wrist. This study selected 282 Chinese Han Chinese males aged 6.0-21.0 years old. In the course of our study, we proposed a novel deep learning model for extracting and enhancing MRI hand and wrist bone features to enhance the prediction of target MRI hand and wrist bone age and achieve precise classification of the target MRI and regression of bone age. The evaluation metric for the classification model including precision, specificity, sensitivity, and accuracy, while the evaluation metrics chosen for the regression model are MAE. The epiphyseal grading was used as a supervised method, which effectively solved the problem of unbalanced sample distribution, and the two experts showed strong consistency in the epiphyseal plate grading process. In the classification results, the accuracy in distinguishing between adults and minors was 91.1%, and the lowest accuracy in the three minor classifications (12, 14, and 16 years of age) was 94.6%, 91.1% and 96.4%, respectively. The MAE of the regression results was 1.24 years. In conclusion, the deep learning model proposed enabled the age assessment of hand and wrist bones based on MRI.

Internationally, the quality of death certification is poor although there are multiple efforts underway to improve the process. In England, a new medical certification system has been proposed to improve the quality of data. We surveyed general practitioners (n = 95) across the West Yorkshire area of England to appraise their views regarding whether further possible changes to the death certification system could promote their quality.

Post-mortem computed tomography (PMCT) is routinely used at many forensic institutions to guide the following autopsy and is especially useful for diagnosing fractures. This systematic review aims to investigate the sensitivity and specificity of a PMCT scan in fracture diagnosis of the hyoid-larynx complex (HLC) compared to traditional autopsy in cases involving traumatic neck injuries. We searched PubMed, SCOPUS and Web of Science and included papers with cases n ≥ 3 published between January 2000 and April 2023 reporting on PMCT and autopsy findings of fractures of the HLC. The search provided 259 results of which 10 were included. Overall sensitivity and specificity were 0.70 [0.59; 0.79] and 0.92 [0.80; 0.97] for hyoid bone fractures and 0.80 [0.62; 0.91] and 0.76 [0.63; 0.85] for the thyroid cartilage. The results show great variation, and a large range between studies. These results indicate that PMCT cannot replace autopsy in cases with HLC fractures. Future larger prospective studies are needed, examining fracture details, scan protocols and different slice thicknesses using uniform reporting.

Hereditary connective tissue disorders (HCTDs) are a heterogeneous group of inherited diseases. These disorders show genetic mutations with loss of function of primary components of connective tissue, such as collagen and elastic fibers. There are more than 200 conditions that involve hereditary connective tissue disorders, while the most known are Marfan syndrome, Osteogenesis Imperfecta, and Ehlers-Danlos syndromes. These disorders need continuous updates, multidisciplinary skills, and specific methodologic evaluations sharing many medicolegal issues. Marfan syndrome and Ehlers-Danlos syndromes show a high risk of early sudden death. As a consequence of this, postmortem genetic testing can identify novel genotype-phenotype correlations which help the clinicians to assess personalized cardiovascular screening programs among the ill subjects. Genetic testing is also essential to identify children suffering from Osteogenesis Imperfecta, especially when a physical abuse is clinically suspected. However, this is a well-known clinical problem even though there are still challenges to interpret genetic data and variants of unknown significance due to the current extensive use of new genetic/genomic techniques. Additionally, the more significant applications and complexities of genomic testing raise novel responsibilities on the clinicians, geneticists, and forensic practitioners as well, increasing potential liability and medical malpractice claims. This systematic review provides a detailed overview on how multidisciplinary skills belonging to clinicians, medicolegal consultants, radiologists, and geneticists can cooperate to manage HCTDs from autopsy or clinical findings to genetic testing. Thus, technical aspects need to be addressed to the medicolegal community since there is no consensus works or guidelines which specifically discuss these issues.

Despite the improvements in forensic DNA quantification methods that allow for the early detection of low template/challenged DNA samples, complicating stochastic effects are not revealed until the final stage of the DNA analysis workflow. An assay that would provide genotyping information at the earlier stage of quantification would allow examiners to make critical adjustments prior to STR amplification allowing for potentially exclusionary information to be immediately reported. Specifically, qPCR instruments often have dissociation curve and/or high-resolution melt curve (HRM) capabilities; this, coupled with statistical prediction analysis, could provide additional information regarding STR genotypes present. Thus, this study aimed to evaluate Qiagen's principal component analysis (PCA)-based ScreenClust^® HRM^® software and a linear discriminant analysis (LDA)-based technique for their abilities to accurately predict genotypes and similar groups of genotypes from HRM data. Melt curves from single source samples were generated from STR D5S818 and D18S51 amplicons using a Rotor-Gene^® Q qPCR instrument and EvaGreen^® intercalating dye. When used to predict D5S818 genotypes for unknown samples, LDA analysis outperformed the PCA-based method whether predictions were for individual genotypes (58.92% accuracy) or for geno-groups (81.00% accuracy). However, when a locus with increased heterogeneity was tested (D18S51), PCA-based prediction accuracy rates improved to rates similar to those obtained using LDA (45.10% and 63.46%, respectively). This study provides foundational data documenting the performance of prediction modeling for STR genotyping based on qPCR-HRM data. In order to expand the forensic applicability of this HRM assay, the method could be tested with a more commonly utilized qPCR platform.

Most of the sexual assault casework samples are of mixed sources. Forensic DNA laboratories are always in the requirement of a precise technique for the efficient separation of sperm and non-sperm DNA from mixed samples. Since the introduction of the differential extraction technique in 1985, it has seen significant advancements in the form of either chemicals used or modification of incubation times. Several automated and semi-automated techniques have also adopted the fundamentals of conventional differential extraction techniques. However, lengthy incubation, several manual steps, and carryover over non-sperm material in sperm fraction are some of the major limitations of this technique. Advanced cell separation techniques have shown huge promise in separating sperm cells from a mixture based on their size, shape, composition, and membrane structure and antigens present on sperm membranes. Such advanced techniques such as DEParray, ADE, FACS, LCM, HOT and their respective pros and cons have been discussed in this article. As current-day forensic techniques should be as per the line of Olympic slogan i.e., faster, higher, stronger, the advanced cell separation techniques show a huge potential to be implemented in the casework samples.

This study explores the reliability of four established legal age threshold estimation approaches in a Croatian sample. We applied Haavikko stages, Demirjian stages, Olze's third molar eruption stages, and second and third molar maturity indices measurement in 593 orthopantomograms of Croatian children and adolescents aged 11.00-20.99 years old. The left mandibular second and third molar were assessed. Logistic regression analysis was conducted to test the significance of predictive variables. Logistic Receiver operating characteristic (ROC) curves were performed to evaluate the classification ability of variables for estimating 14- and 16-year-old thresholds. The areas under the ROC curve (AUC), accuracy (Acc), sensitivity (Se), specificity (Sp), Positive Likelihood Ratio (LR +), Negative Likelihood Ratio (LR-), and Bayes post-test probability (Bayes PTP) were calculated to evaluate classification performance. Results suggest that the combination of I_2M&I_3M is the best classifier for the 14-year-old threshold (AUC = 0.879); for males alone, I_2M is an even better classifier (AUC = 0.881). The highest Acc 80.1% (95%CI, 75.9%-83.9%), Bayes PTP 86.5% (95%CI, 82.8%-89.7%) and Sp 88.9% (95%CI, 83.0%-93.3%) were by I_3M < 0.81 & I_2M < 0.03 in total samples; the highest Acc 86.1% (80.6%- 90.6%), Bayes PTP 87.2% (95%CI, 81.7%- 91.4%) and Sp 87.8% (95%CI, 78.2%- 94.3%) were by I_2M < 0.01 in males, Acc of Haavikko Ac and Demirjian H stage in second molar is very close with slightly lower Bayes PTP and Sp. I_3M is a good classifier for 16-year-old threshold (AUC = 0.889). The cut-off value I_3M < 0.34 can be used to classify the 16-year-old threshold with Acc of 80.6% (95%CI, 77.2%-83.7%), Sp of 83.4% (95%CI, 79.0%-87.3%), and 81.7% (95%CI, 78.4%-84.8%) Bayes PTP. In conclusion, to classify the 14-year-old threshold, a pair of cut-off values I_3M < 0.81 & I_2M < 0.03 can be used in Croatian females; I_2M < 0.01, Demirjian H stage, Haavikko Ac stage in second molar, and the pair I_3M < 0.81 & I_2M < 0.03 can all be used in Croatian males. I_3M < 0.34 can classify the 16-year-old threshold in Croatian populations.

The importance of non-human DNA in the forensic field has increased greatly in recent years, together with the type of applications. The molecular species identification of animal and botanical material may be crucial both for wildlife trafficking and crime scene investigation. However, especially for forensic botany, several challenges slow down the implementation of the discipline in the routine.Although the importance of molecular analysis of animal origin samples is widely recognized and the same value is acknowledged to the botanical counterpart, the latter does not find the same degree of application.The availability of molecular methods, especially useful in cases where the material is fragmented, scarce or spoiled preventing the morphological identification, is not well known. This work is intended to reaffirm the relevance of non-human forensic genetics (NHFG), highlighting differences, benefits and pitfalls of the current most common molecular analysis workflow for animal and botanical samples, giving a practical guide. A flowchart describing the analysis paths, divided in three major working areas (inspection and sampling, molecular analysis, data processing and interpretation), is provided. More real casework examples of the utility of non-human evidence in forensic investigations should be shared by the scientific community, especially for plants. Moreover, concrete efforts to encourage initiatives in order to promote quality and standardization in the NHFG field are also needed.