International Journal of Legal Medicine最新文献

The majority of crime scenes contain DNA that is either present in small amounts or degraded, making it difficult to obtain usable DNA profiles using conventional technologies. The current standard for analyzing casework samples is the specific amplification of short tandem repeats (STR), which is limited by DNA quality and quantity. Since the goal of forensic science is to identify a suspect or victim regardless of trace quality, we evaluated three technological approaches to better characterize and exploit these traces: (i) ultra-sensitive pulse-field electrophoresis on a Femto Pulse System (FPS) to visualize DNA content, (ii) real-time quantitative PCR based on Alu repeats to quantify human DNA and analyze its integrity, and (iii) 16S ribosomal RNA gene (16S rRNA) amplicon sequencing to identify microbiota. We optimized FPS analysis using DNA from model traces (blood, saliva, semen, touch DNA, and vaginal swabs) and applied the protocol to 100 casework samples. We found differences between the FPS profiles of model and casework samples, showing a variation in fragment size and distribution, suggesting the presence of non-human DNA. Using Alu-qPCR and 16S rRNA amplicon sequencing, we determined the amount and proportion of human and non-human DNA. Human DNA was detected in 84% of traces with an average of 70 pg per trace, while 16S rRNA revealed microbial DNA as the most abundant DNA in traces. These analyses provide new insights into forensic trace composition, allowing better sorting and profiling of traces.

Applying existing sexing methodologies to different populations, and reporting these findings is important to enhance their applicability and accuracy in real cases across the world. DSP was published in 2005 (Murail et al., 2005) and updated as a DSP2 in 2017 (Brůžek et al., 2017) based on a database of 10 pelvic measurements from 2040 individuals worldwide. These tools have been applied subsequently to various populations, however, its applicability to a dry Spanish population is lacking. 303 hipbones belonging to 157 individuals from the School of Legal Medicine from the University Complutense of Madrid (Spain), of which 140 individuals were documented, were analyzed to investigate the reliability, applicability and accuracy of the DSP2 sex estimation methodology, examining side and sex-based potential differences for the first time. In most of the DSP variables, intra-rater reliability showed excellent results and % applicability was higher than 85.0%. Overall % accuracy was higher than 94.0% regardless of the number or discriminant power of the utilized DSP variables. However, % sexing decreased when less variables or less discriminant ones were used for estimations, reaching 45.51% (left) and 43.31% (right). Regarding sexual dimorphism, females' results of % applicability, % sexing and % accuracy were higher compared to males. In addition, left os coxae achieved better outcomes (aforementioned percentages) in most of the cases in the sex-pooled sample. Decreasing the mandatory posterior probability by 10% yielded an increase in the % sexing but reduced % accuracy, and thus, does not seem to enhance the approach's performance. The present study validates the applicability and reliability of DSP for sexing a Spanish population. Future investigations will attempt to assess its applicability within virtual anthropology.

Uniparental disomy (UPD) is the abnormal situation in which both members of a chromosome pair exclusively comprise material of one of the parents. The incidence of UPD is estimated in 1:2000 live births. This rare condition is relevant for medical genetics due to imprinting disorders or recessive diseases; however, it may also impact for parentage testing, leading to apparent false parentage. Herein we report the results of a paternity test in which four inconsistencies were observed, all of them mapped on chromosome 2. To investigate the possibility of a complete maternal compound hetero/isodisomy UPD2 as an alternative to false exclusion paternity result, SNP-array and Y-chromosome haplotyping were additionally performed. The results were compatible with the occurrence of a maternal UPD2. Review of the literature shows that UPD2 represents about half of the UPDs detected in parentage tests. The case reported here illustrates that UPD should be considered in cases of parentage testing exhibiting inconsistencies of at least two markers exclusively in a single chromosome.

Background: Sexual violence (SV) while travelling internationally is underreported and pre-travel advice is often focussed on broader tourist safety concerns. International travellers who experience sexual violence face particular challenges. The aim of this paper was to analyse the attendances of people who disclosed having been subjected to SV during international travel to the Sexual Assault Treatment Unit (SATU) network in the Republic of Ireland.

Methods: Analysis of all people who attended the national SATU network who disclosed an incident of SV experienced during international travel, and comparison of these cases with domestic case attendances.

Results: During the 7-year period studied, there were 6,447 attendances to the national SATU network, with 443 incidents reported as occurring outside Ireland; in 66 separate countries. The mean age of international attendees was 26.61 years, with females representing 90.3% of cases. Where an incident occurred internationally, the patient was less likely to disclose drug ingestion in the 24 h preceding the incident (p < 0.001) and significantly less likely to be assaulted in the assailant's home (p = 0.009) when compared with domestic cases. Those who were assaulted internationally were significantly more likely to be assaulted by a stranger or recent acquaintance, i.e. ( p < 0.001).They were also more likely be assaulted in a location recorded as 'other indoors' (e.g. hotel, hostel etc) (p < 0.001). There was no significant difference in alcohol consumption (p = 0.115) or frequency of assaults occurring outdoors (p = 0.155).

Conclusion: Our study has shown that 7% of attendances to the SATU network followed incidents of SV that occurred during international travel. The majority of these incidents were disclosed as being perpetrated by a stranger or recent acquaintance, in an indoor setting with over half having occurred in Europe. Individuals who experience SV while travelling abroad should be encouraged to seek immediate medical attention and appropriate follow-up care upon returning home.

The aim of this study is to investigate the potential of radiomic features extracted from postmortem computed tomography (PMCT) scans of the lateral cerebral ventricles (LCVs) to provide information on the time since death, or postmortem interval (PMI), a critical aspect of forensic medicine. Periodic PMCT scans, referred to as "sequential scans", were obtained from twelve corpses with known times of death, ranging from 5.5 to 273 h postmortem. Radiomics features were then extracted from the LCVs, and a mixed-effect model, specifically designed for sequential data, was employed to assess the association between feature values and PMI. Four model variants were fitted to the data to identify the best functional form to explain the relationship between the variables. Significant associations were observed for features, the most significant being the median Hounsfield Units (HU) within the LCVs (p < 9.47 × 10⁻⁹), LCVs surface area (p < 4.69 × 10⁻⁶), L-major axis (p < 2.17 × 10⁻⁵), L-minor axis (p < 1.30 × 10⁻⁴), and HU entropy (p < 4.16 × 10⁻⁴). Our findings align with previous studies, supporting a logarithmic model for PMI-related changes in LCV volume and mean HU intensity value. This study highlights the potential of PMCT-based radiomics as source of complementary information that could be integrated into existing methods for PMI estimation. Our results support the application of a quantitative imaging approach in forensic investigations.

Genetic markers of the Y chromosome are powerful tools for investigating paternal ancestry and are widely used in population and forensic genetics. However, in order to obtain statistics with a higher degree of certainty using these markers, it is necessary to obtain haplotypic frequencies from a representative database, as well as knowing the diversity and structure of the population. The aim of this study was to investigate the genetic diversity of a sample of 1114 unrelated men from three states in the Northeast of Brazil: Paraíba, Pernambuco and Ceará, through the analysis of 23 Y-STRs and to contribute to the expansion of the Brazilian database on these markers. The PPY23 panel had a high discriminatory power, and the population structure was consistent with the historical aspects of the colonization of the Northeast of Brazil. Population comparisons based on paired genetic differentiation values (Fst) revealed no statistically significant differences between the three populations in this study. However, it was observed that Pernambuco and Paraíba were genetically closer to states outside the Northeast region. Y-STR-based haplogroup prediction, carried out using the NevGen software, revealed that the paternal lineage of the populations in this study is essentially European, with little African or Native American influence, just like the rest of the Brazilian population. Additionally, this work contributes to a more representative database for use in forensic and population genetics.

Estimating the postmortem interval (PMI) is a critical yet complex task in forensic investigations, with accurate and timely determination playing a key role in case resolution and legal outcomes. Traditional methods often suffer from environmental variability and subjective biases, emphasizing the need for more reliable and objective approaches. In this study, we present a novel predictive model for PMI estimation, introduced here for the first time, that leverages pathological tissue images and artificial intelligence (AI). The model is designed to perform under three temperature conditions: 25 °C, 37 °C, and 4 °C. Using a ResNet50 neural network, patch-level images were analyzed to extract deep learning-derived features, which were integrated with machine learning algorithms for whole slide image (WSI) classification. The model achieved strong performance, with micro and macro AUC values of at least 0.949 at the patch-level and 0.800 at the WSI-level in both training and testing sets. In external validation, micro and macro AUC values at the patch-level exceeded 0.960. These results highlight the potential of AI to improve the accuracy and efficiency of PMI estimation. As AI technology continues to advance, this approach holds promise for enhancing forensic investigations and supporting more precise case resolutions.

Introduction: Age estimation is vital in dentistry and legal contexts to determine minors' criminal responsibility. This study aimed to estimate and classify bone and dental age in a Portuguese population, using the Greulich-Pyle method and the Moorrees Fanning and Hunt method, comparing the accuracy of both methods.

Materials and methods: 597 left hand and wrist radiographs and 184 orthopantomographs were selected, and the methods were applied.

Results: Cohen's weighted kappa coefficient ranged between 0.890 and 1. Both methods underestimate age. The linear regression formulas showed strong correlations between estimated and real age (0.902 for bone age assessment and 0.894 for dental age assessment). For the bone assessment the accuracy is highest at 14 and 18 years, with similar values to those at 12 and 16. The AUC shows that the method is more reliable at 12 and 14 years. For the dental age assessment, a lower sensitivity value was observed for the age of 12 (73.91%) and a higher for 18 years (91.03%), increasing with age. The accuracy was higher at 12 years (89.62%) and lowest at 18 years (83.02%). Specificity values were higher for ages 12 and 14 (93.98% and 95.24%, respectively). The lowest AUC value was recorded for 18 years (0.889), while for ages 12, 14, and 16, the values were similar, indicating lower reliability for the legal age of 18.

Conclusion: For individuals under 12, 14, 16, and 18 years old, the bone method is the most effective. However, combining both methods allows greater accuracy and consistency in age estimation for medico-legal applications.

To investigate the applicability of the Vieth classification and characteristics of ossification age in knee joint in adolescents of northern China. A retrospective study was conducted on a total of 1517 MRI images of knee joints from patients aged 10 to 20 years in the northern China. Vieth classification was used to assess the ossification age of distal femur and proximal tibia. Descriptive analysis was performed to obtain the maximum, minimum, median, and upper and lower quartiles of age at each stage, stack bar graph were used to show the age distribution at each stage. Mann-Whitney U test was utilized to analyze the differences in the stage of the proximal tibia and distal femur. Good intra-observer and inter-observer consistency (к = 0.89 and 0.88) was obtained. Regarding the distal femoral epiphysis, 100% of male participants in stage 3, 4(and 5) and 6 were over 12, 14 and 16 years old, respectively; 100% of female participants in stage 4, 5 and 6 were over 12, 14 and 16 years old. While for proximal tibial epiphysis, 100% of male participants in stage 4 and 5 were over 12 and 14 years old; 100% of female participants in stage 4 and 5 were over 12 years old. Ossification age of the proximal tibia mature earlier than distal femur (P < 0.001). Vieth classification can be used to infer the age of 12, 14 and 16 years in adolescents of northern China, providing a valuable reference for forensic age estimation.