Journal of forensic sciences最新文献

At the core of the common law, rooted in fairness, is the principle that an accused must be “fit” or “competent” to answer charges pursued by the state. Fitness rules vary considerably across jurisdictions but generally share the requirement that the accused be able to actively participate in the conduct of their defense. In the Canadian tradition, the common law on fitness is codified in Section 2 of the Criminal Code. For over 30 years, statutory interpretation of the law has been limited to provincial courts of appeal in Canada. Now, for the first time, the Supreme Court of Canada has rendered an opinion on the fitness test, thus creating new binding case law across the country on the question. Largely endorsing decisions rendered in the Ontario Court of Appeal in Taylor, and then Bharwani, the Supreme Court has endorsed a broadened test and fuller interpretation of the statute, highlighting that defense decisions must be reality-based and communicated intelligibly. Fluctuations in fitness are acknowledged, and while symptoms may be present, they must not be overwhelming in nature. Here, we review the legislative and judicial history leading to the decision in R v. Bharwani before providing a psycholegal analysis of the decision and a review of its implications for forensic mental health professionals. Beyond utility to those practicing in Canada, this historic and landmark ruling is thought to be instructive to those in America and other Commonwealth nations around the world grappling with the nuances of competency capacity thresholds.

Elevated beta-hydroxybutyrate (BHB) is a marker for ketoacidosis. Post-mortem values for the diagnosis of fatal ketoacidosis and the associated clinical and histologic findings are limited in the pediatric population. A retrospective case series of pediatric autopsy records and histology slides was conducted. Deaths occurring between 2010 and 2022 of children (ages<18 years) with an elevated BHB level (vitreous BHB >2 mmol/L or blood >200 mg/L) were analyzed. Histology of the heart, lung, liver, and kidneys was reviewed and scored. Five hundred twelve pediatric autopsies were conducted during the study period, of which 20 cases (3.9%) met the inclusion criteria. The age ranged from stillborn to 17 years, with a mean age of 6.3 years and a median age of 3.5 years. The mean concentration of vitreous BHB was 3.9 mmol/L (median 2.69; range 2.0–11.86 mmol/L; n = 17 cases) and the blood BHB had a mean of 416 mg/L (median 291; range from <50 mg/L to 1188 mg/L; n = 9 cases). Death was attributed to diabetic ketoacidosis, infection, malignancy, trauma, congenital heart disease, and drug toxicity. Histological changes were seen in all tissues examined in this pediatric population including hepatic steatosis (n = 17), glycogenated hepatocyte nuclei (n = 5), renal tubular vacuoles (n = 7) and heart vacuoles (n = 9). The only statistically significant correlation was found between vitreous BHB and renal tubular vacuoles (p = 0.014). Overall, elevated BHB levels were identified in blood and/or vitreous in fatal diabetic and non-diabetic cases, including infection. Diabetic ketoacidosis had the highest level of BHB at 11.86 mmol/L.

Restraint-related sudden deaths in agitated individuals raise complex questions at the intersection of medicine and law. Hyperactive delirium with extreme agitation as well as positional asphyxia due to restraint have been proposed to account for these deaths. However, the exact physiological mechanisms responsible and to what extent restraint contributes to the lethal outcome remain debated. In this nationwide, 32-year retrospective study between 1992 and 2024, we examined circumstances surrounding sudden deaths during restraint of agitated individuals in Sweden. A total of 52 cases were identified, with an average of 0.17 deaths per million inhabitants annually. Ninety percent of cases involved prone restraint and 69% showed evidence of stimulant use. In 15 cases from 2005 onward, peri-arrest arterial blood gas data revealed profound metabolic and respiratory acidosis, with a mean blood pH of 6.52 (range: 6.30–6.95; median: 6.50), mean lactate concentration of 26.3 mmol/L (range: 8.6–41.0; median: 30), and mean pCO₂ of 14.8 kPa (range: 6.4–22.3; median: 15.3). Based on these findings, we propose a two-phase pathophysiological model of restraint-related cardiac arrest. The initial “priming phase” involves extreme physical exertion, creating a critically acidotic state that requires full respiratory and cardiovascular function to maintain homeostasis. If the “priming phase” is followed by restraint that restricts ventilatory function and hampers venous return, e.g., restraint in the prone position, an unstable “tipping phase” is initiated, that may culminate in cardiac arrest. This model builds on previous hypotheses and emphasizes the potentially lethal consequences of inhibiting ventilatory function in acutely agitated individuals.

Zolpidem, a non-benzodiazepine hypnotic, is one of the most widely prescribed sleep aids in South Korea and is frequently implicated in forensic toxicology. A retrospective analysis was conducted on zolpidem-positive autopsy cases (N = 1583) investigated by the National Forensic Service between 2022 and 2024. The manner and cause of death were classified, and zolpidem concentrations were measured in three biological matrices: peripheral blood (PB), cardiac blood (HB), and liver. Zolpidem analysis was performed using gas chromatography–mass spectrometry (GC/MS) and liquid chromatography–tandem mass spectrometry (LC–MS/MS) following solid-phase extraction (SPE). Among zolpidem-positive autopsies, suicide accounted for 43.1% (n = 676), with drug poisoning representing the dominant method (72.8% of suicides). In drug-related suicide cases (n = 251), zolpidem was the sole detected agent in 15.1%, while the majority (84.9%) involved poly-drug exposure. A wide range of non-pharmaceutical toxicants—including carbon monoxide, agrochemicals, chemical substances such as gases, nitrite, ethylene glycol, cyanide, and other miscellaneous agents—were also co-detected. Zolpidem was also the most frequently detected drug in driving under the influence of drugs (DUID) cases (30.0%) and drug-facilitated sexual assault (DFSA) submissions (5.1%) during the study period, highlighting its role in both fatal and nonfatal forensic toxicology. These findings emphasize the importance of appropriate clinical use, matrix- and context-specific toxicological assessment, and strengthened public health strategies to address the potential risks associated with zolpidem use.

This study investigated relationships between bullet mass, velocity, kinetic energy (KE), and fracture propagation in flat bones. Sixty full metal jacketed 9-mm bullets of different masses were fired at pig (Sus scrofa) scapulae. A chronograph measured bullet velocity prior to impact. Fracture characteristics were documented using standard terminology, counted, and measured at the entrance aspect, exit aspect, and overall per specimen. Few significant relationships between ballistic and fracture variables were found across the ranges tested, suggesting possible threshold effects. Bullet mass influenced velocity, suggesting that KE is the most practical variable for interpreting trauma in forensic contexts. Side-specific analyses showed entrance fracture length was primarily driven by long individual radial cracks, while exit fracture length reflected more cracks, more diverse crack types, and longer individual cracks. These findings provide a baseline for future research and underscore the utility of a standardized, quantitative, and surface-specific framework for documenting fracture characteristics.

Forensic anthropologists commonly estimate osteological sex using separate morphological and metric analyses, without integrating both data types into a single classification model. Combining data types into one model has the potential to increase sex classification accuracies for the skull. Therefore, the present study seeks to improve classification accuracies for the skull by combining morphological and metric variables using random forest (RF) modeling. The main objectives are (1) generate multiple RF models that incorporate various combinations of morphological and metric variables for estimating osteological sex from an unknown individual, (2) compare the performance of morphological, metric, and combined data RF models, and (3) compare the results of the RF models to current methods for osteological sex estimation of the skull. The sample included 212 European Americans (males = 106, females = 106) and 191 African Americans (males = 114, females = 77). The models were trained on 80% of the sample and tested using a 20% holdout sample. Multiple models were generated using morphological, metric, and combined variables. Across all model types, the skull and cranium models achieved higher accuracies compared to the mandible models. The morphological and combined models attained higher accuracies compared to the metric models. Additionally, the morphological and combined RF models attained comparable classification accuracies to current standard osteological sex estimation methods, as well as compared to previous studies that integrated skull measurements and traits. Future research should continue exploring RF modeling for osteological sex estimation, including models combining metric and morphological variables from multiple skeletal regions.

A significant portion of document fraud cases, often associated with organized crime, involves the manipulation of physical records using correction materials such as pen or fluids and tapes. Although these materials are visually similar, they differ in chemical composition. Fluids typically contain volatile organic solvents and pigments, while tapes consist of pigment-coated adhesive films. In this study, the ATR-FTIR spectroscopy as a non-destructive analytical technique was explored to obtain spectral data from 205 prepared samples of correction materials and visually similar substances. PCA was used for exploratory data reduction, followed by PLS-DA for supervised classification based on spectral patterns. Further, feature importance was interpreted using VIP and coefficient plots, highlighting key wavenumbers contributing to class separation. The developed models exhibited excellent performance, achieving 100% accuracy in external validation for differentiating correction materials from similar-looking substances, as well as discriminating between correction pen and correction tape samples. The findings demonstrate that ATR-FTIR spectroscopy coupled with chemometrics provides a fast, accurate, and non-destructive method for the forensic classification of correction materials, offering substantial utility in real-world document examination scenarios. Further, the spectral repository developed in this study offers a valuable reference resource for forensic document examiners, aiding in the identification of questioned materials and supporting the investigation of document forgery cases.

This study monitored the transfer of inorganic and organic gunshot residues (IGSR and OGSR) in cases where indirect exposure might be questioned, such as during arrests. Mock arrest scenarios (n = 180) were created to assess the effect of two variables on the secondary transfer. First, the level of contact between the detained and the officer (low, medium, and high) during the arrest protocols. Second, the activities preceding the arrest include situations where the officer or person of interest (POI) discharges a firearm or handles a gun without firing. Additionally, measures to mitigate the risk of GSR transfer from the arresting officer and surfaces were evaluated. This included variables like hand washing, wearing various types of gloves, and bagging the POI's hands during transport in a police vehicle (n = 70). All samples underwent screening (ECD and LIBS) and confirmatory analysis (SEM–EDS and LC–MS/MS). The results indicated that IGSR and OGSR behave differently, with their transfer and persistence varying according to the level of contact, activities, and exposure prior to arrest. Secondary transfer was observed in 69% of the experiments but was less likely to occur for OGSR than for IGSR. The OGSR was more prone to loss, as it was not detected in 93% of the medium- and high-contact scenarios. Preventive measures such as hand washing, wearing nitrile gloves, or bagging hands helped decrease the characteristic IGSR particle counts from 5–80 to none-11. These findings enhance the current knowledge of IGS/OGSR transfer and persistence while providing recommendations for arrest protocols and evidence collection.

Multifactorial age estimation is preferred over methods based on a single anatomical site. The main challenge of the multifactorial methods lies in calculating the overall prediction interval. This study compared the performance of two approaches to achieve this: the minimal age principle versus a Bayesian approach. MRI of the third molars, left hand/wrist, and sternal extremity of both clavicles were prospectively conducted in 335 healthy Austrian Caucasian males aged 13–24 years. Development was staged according to De Tobel et al. Multi-factorial age estimation: A Bayesian approach combining dental and skeletal magnetic resonance imaging. Forensic Sci Int. 2020;306:110054. Applying the minimal age principle rendered a mean absolute error of 1.47 years, root mean square error of 1.81 years, mean width of the 95% prediction interval (PI) of 4.44 ± 2.49 years, and coverage of 68.7%. For the Bayesian approach, the results were 1.41, 1.80, 5.15 ± 1.94 years, and 81.5%, respectively. Higher inconsistency between the different age indicators was linked to a lower coverage probability in the minimal age principle, but not in the Bayesian approach. Moreover, higher inconsistency between age indicators was also linked to a higher probability of obtaining an impossible PI with the minimal age principle. Furthermore, applying the minimal age principle rendered 97.9%/81.0% correctly categorized adults (based on the point prediction of age/based on the PI) and 69.2%/85.6% correctly categorized minors. For the Bayesian approach, the results were 95.2%/76.2% and 81.5%/95.9%, respectively. In conclusion, the Bayesian approach outperformed the minimal age principle for multifactorial forensic age estimation, allowing the construction of more appropriate PIs and more correctly categorized minors.

This study investigated links between skeletal age estimation error and lifestyle variables to better elucidate sources of interpersonal variability in the rates of skeletal aging. Skeletal age for 180 individuals from the New Mexico Decedent Image Database was estimated by applying the Suchey–Brooks method and transition analysis to 3D models of the pubic symphysis, and age estimates were compared to known age-at-death. Age estimation bias and accuracy for both methods were evaluated first with respect to single lifestyle variables, then random forest modeling was used to test variability with respect to all lifestyle variables. Age estimation bias was shown to be significantly different with respect to sex when applying transition analysis, but not when applying Suchey–Brooks, and males tended to be underaged relative to females of the same age. While no statistically significant differences in bias existed for either method between BMI categories, random forest modeling indicated that body size exerts a limited but variable influence on skeletal aging. Additional variables were highlighted as potentially influential to skeletal aging by random forests, such as socioeconomic status, but ultimately, model performance and variable importance plots demonstrated that these influences were slight and nonuniform. These data suggest that including considerations of lifestyle variables in skeletal aging methods would not improve aging estimates.