Journal of forensic sciences最新文献

The increasing accessibility of 3D printing, made possible by the affordability of equipment and materials, has led to its widespread adoption in both domestic and industrial applications, with polylactic acid (PLA) being a commonly used material. The layer-by-layer deposition process in fused deposition modeling creates surface texture variations that significantly influence the development and recovery of latent fingermarks. This study examined the effect of raster lines on fingermark development by depositing latent fingermarks on the X, Y, and Z faces of 3D-printed PLA objects. Powder development was applied both along and against the 3D print grain. Development against the grain caused excess powder accumulation within raster lines, partially obscuring ridge detail. In contrast, applying powder along the grain minimized accumulation, enabling clearer visualization of ridge features. Top and side surfaces generally yielded higher quality grades, attributed to smoother surfaces from better interlayer bonding. However, raster lines created discontinuities in ridge transfer, hindering coincident sequence determination. Cyanoacrylate ester fuming effectively addressed this limitation, producing continuous ridge detail on top and side surfaces, and leading to higher quality grades.

Benzimidazole opioids, isotonitazene (ITZ), and metonitazene (MTZ) and their associated metabolites, 5-aminoisotonitazene (5-AI), 4′-hydroxy nitazene (4′-HN), N-desethyl isotonitazene (N-DI), and N-desethyl metonitazene (N-DM), were evaluated in human postmortem casework. A total of twenty-seven cases that previously tested positive for ITZ (n = 11) and MTZ (n = 16) in routine case analysis were retested for the presence of metabolites in blood and urine specimens by solid-phase extraction and LC/MS/MS. N-DI was the most prevalent metabolite detected in ITZ cases, present in six blood and four urine samples. N-DM was the most prevalent MTZ metabolite, primarily found in urine. 4′-HN was detected in both ITZ and MTZ cases. Fentanyl was the most prevalent co-finding, and all cases were classified as mixed drug intoxications except for two blunt force traumas. Due to the reported potency of N-DI and prevalence of metabolite detection in these cases, this study encourages the addition of nitazene metabolites to routine testing scopes.

Differentiating between abusive and accidental skin lesions in children presents significant challenges. Previous studies of skin lesion patterns have mainly focused on bruises in younger children. In this study, we compare the number, location, and distribution of recent (bruises and abrasions) and older (scars) skin lesions between police-reported cases of physical violence and controls of similar age (4–14 years) in a Danish setting. The study included 262 cases and 119 controls. Skin lesions in 19 body regions were assessed. Univariate and multivariate logistic regression models were conducted including body regions, age group, sex, and activity level. Having scars on the buttocks was conclusively associated with the case group (OR: 5.0; 95% CI: 1.5–17). There was a tendency for cases to have more scars on the upper arms, hands, lower parts of the back (midline), and legs. We did not find an association between recent skin lesions (bruises and abrasions) and physical violence. A difference in activity levels between cases and controls may explain the higher number of recent lesions in the control group. It is crucial to promptly examine children exposed to violence. If this is not possible, examining for older skin lesions remains important.

Tracking law enforcement-associated fatalities is complicated by an absence of a national database. Death certificates often fail to report deaths due to law enforcement activity. Adopting recommendations by the National Association of Medical Examiners, the present study was conducted using records from the King County Medical Examiner's Office of all deaths associated with law enforcement, including deaths in correctional facilities, from 1995 to 2024. A total of 566 deaths were categorized as Pre-Custody (299) or In-Custody (267). Pre-Custody deaths were subcategorized into: Shooting (178), Vehicular Pursuit (57), Restraint (24), and Other (40). An altercation with law enforcement (40 deaths) or with other individuals (11 deaths) was the most common circumstance preceding the fatal event in the Pre-Custody/Shooting subcategory. In the Pre-Custody/Restraint group, multiple factors contributed to the deaths of all but 5, and stimulant drug intoxication contributed to the deaths of 19. No deaths were caused by tasers or pepper spray. In the In-Custody category, manners of death and demographics differed between deaths from jails and prisons. Racial and ethnic disproportionalities, relative to the county population, were evident in both Pre- and In-Custody deaths. Death certificates mentioned law enforcement involvement in 74% of the Pre-Custody/Shooting deaths and in only 12% of In-Custody deaths due to injuries. As public policies evolve to guide modern policing, creating a national database is imperative. Medical examiners and coroners have an important role in this effort by providing appropriate descriptions in the Describe How Injury Occurred section of death certificates.

In forensic saliva testing, false negatives of the Phadebas® and false positives of the RSID™-saliva methods generated by citric acid are critical issues for interpreting the results. Citric acid-containing beverages, which are typically mixed with forensic saliva samples, may produce indistinguishable results in two commercially available saliva tests in the presence and absence of saliva. To solve this issue, this study aimed to evaluate the usefulness of the indirect enzyme-linked immunosorbent assay (ELISA)-based method of detecting cystatin D to identify saliva in citric acid-containing beverage-mixed samples. Four commercially available beverages were mixed with human saliva or ultrapure water, and the mixed stain samples were examined by the aforementioned three saliva tests. Two conventional saliva tests could not distinguish between the samples with and without saliva. Although the positive detection rates of the ELISA method decreased when mixed with beverages, no saliva-free beverage samples produced false positives. Our results indicate that the detection of cystatin D by indirect ELISA would be useful in identifying saliva from samples potentially mixed with citric acid-containing beverages.

MorphoPASSE is a free program that estimates sex based on morphological traits of the innominate, cranium, or a combined set of traits; however, MorphoPASSE does not provide recommendations on which set of traits performs best or recommend a posterior probability (PP) threshold for sex classification in modern forensic casework. The goals of this study were to compare accuracy rates when using different sets of traits and when imposing posterior probability informed thresholds (PPITs). Innominate and cranial trait score data were collected from four modern US documented skeletal collections (n = 285). Accuracy rates for five mutually exclusive PP intervals were calculated, and PP intervals that were significantly different from chance were condensed into PPITs. Using a PPIT of 0.85–1.00 produced high accuracy rates of 97.3% for the innominate traits and 90.2% for the cranial traits. Using the combined set of innominate and cranial traits resulted in significantly higher accuracy (99.6%) with a lower PPIT of 0.75–1.00. Additionally, the combined trait model corrected all previous misclassifications by either producing a correct sex classification or leaving the individual unclassified for failing to reach the required PPIT. Therefore, when both elements are available, the combined set of traits is recommended with a 0.75–1.00 PPIT. Individuals with a PP falling between 0.75 and 1.00 should be reported as consistent with the male or female reference samples, while those falling below should be reported as “could not be estimated.” Use of these recommendations will help standardize the use of MorphoPASSE and reporting sex estimation results.

Confirmatory semen tests are used to determine the possible presence of semen in an evidence sample. Current test kits target proteins like PSA and semenogelin, but these markers can yield false positive results when identifying potential semen evidence. This study evaluated the sensitivity and specificity of three rapid immunochromatographic semen detection kits: RSID™ Semen, Seratec™ PSA, and ABAcard™ p30. These kits are marketed as confirmatory tests for semen. Test samples included serial semen dilutions, bodily fluids, and materials previously shown to cause false positives. All tests were performed according to manufacturers' protocols. Combined test results indicated a 9.4% false positive rate. False positives occurred across all kits with absorbent hygiene products (e.g., tampons, menstrual pads, and diapers). RSID™ Semen failed to detect semen in a 1:10,000 dilution and when mixed with dirt, indicating a 3% false negative rate and a false positive rate of 9%. ABAcard™ p30 produced false positives with female urine. While Seratec™ PSA demonstrated the highest sensitivity with only a 1% false negative rate, its false positive rate (12%) was the highest observed. ABAcard™ p30 exhibited superior performance with the lowest false positive rate (6%) and a false negative rate of 2%. While most forensic labs have moved away from using these kits as confirmatory tests, it is vital to emphasize why reporting their results as definitive semen evidence is problematic. These tests cannot confirm semen presence and should not be used alone as confirmatory evidence in forensic reports.

The increased demand for the study of cremated remains, combined with their poor state of preservation, presents anthropologists with highly complex and challenging cases. In this context, cremains weight is considered a stable parameter, not influenced by the fragmentation state of the remains, useful in anthropological investigations. However, few data are available in the literature so far, and no study has been performed on the Italian population. To this purpose, the present study aims to provide cremains weights from a sample of 160 cremations belonging to Italian adult individuals, who were cremated at the Crematorium of Milan (Italy) recently (2012–2014). Mean weights were reported for both sexes, and the relationship with some anthropological and biological variables (i.e., age at death, height, body weight, and body mass index) was evaluated by univariate and multivariate analyses. As expected, the results showed a significant negative relationship with age at death (p-value: <0.01) and a significant positive relationship with the remaining variables, especially in males (p-value: <0.01). Comparison with the literature showed a close similarity with Portuguese data and a midway position between Asian and American samples, thus suggesting an intercontinental variation. However, few pieces of information are available so far to understand such variation, and further analyses are needed to identify the factors able to explain the variation observed. This is the first study supplying cremains weights for a middle-aged and elderly Italian sample. This data could help anthropologists during the evaluation of human cremated remains by complementing or supporting other evidence.

Accurate and reliable decision-making in the criminal justice system depends on accurate expert reporting and on the correct interpretation of evidence by the judges, prosecutors, and defense lawyers. The present study aims to gain insight into the judiciary's capability to assess the accuracy and reliability of forensic expert reports by first examining the extent to which criminal justice professionals are able to differentiate between an accurate (or sound) expert report and an inaccurate (or unsound) expert report. In an online questionnaire, 133 participants assessed both a sound and an unsound expert report. The findings show that, on average, participants were unable to significantly distinguish between sound and unsound forensic expert reports. Second, the study explored the influence of institutional authority on the evaluation of forensic expert reports. Reports that were not recognized as flawed—particularly those originating from well-known and reputable institutions—were subjected to less critical examination, increasing the risk of evaluation errors. These results suggest that the perceived institutional authority influences the assessment of forensic evidence. The study highlights the need for tools to support criminal justice professionals in evaluating forensic evidence, particularly when experts are unregistered. Recommendations include adhering to established quality standards, consulting counter-expert evaluations, improving courtroom communication, and enhancing forensic knowledge through training. Overall, the findings underscore the importance of critical evidence evaluation to reduce the risk of misinterpretation and wrongful convictions in the judicial process.

Traditional barefoot impression examination faces significant limitations in comparing impressions with sock-clad impressions. This paper presents the first cross-comparison study of barefoot and sock-clad impressions in challenging mixed datasets. We propose an enhanced Siamese network approach for the cross-comparison of barefoot and sock-clad impression evidence. Our methodology employs a dual-branch feature extraction framework based on ResNet34, enhanced with a channel-level generalized mean (GeM) pooling strategy and metric learning through hard sample mining. Research utilized 800 right footprint samples from 800 participants, augmented with 800 left footprint samples generated through mirror transformation, totaling 1600 samples for evaluation. Experimental results demonstrate that the proposed method achieves 63.4% Top-1 accuracy and 90.9% Top-10 accuracy in challenging mixed retrieval environments. The ResNet34 architecture with improved GeM pooling showed superior performance compared to alternative network architectures and pooling strategies. This research addresses critical challenges in the comparison of sock-clad impressions to barefoot impressions, particularly for cases where perpetrators wear socks to minimize distinctive impression evidence and sounds in burglary, homicide, and other crimes, providing a more objective, quantifiable automatic comparison method for barefoot and sock-clad impression identification with substantial practical value for criminal investigations.