Journal of forensic sciences最新文献

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.

Breath alcohol simulators are devices that use a heated ethanol/water solution to simulate human breath. Vapor created from heating the solution is commonly used to calibrate alcohol breath testing instruments. When the vapor of the same solution is repeatedly sampled, it causes the ethanol concentration to deplete at a currently unknown rate. The goal of this study was to quantify and better understand the ethanol depletion in non-recirculating system breath alcohol simulators. Simulators were filled with alcohol reference solutions, and air was pumped through the simulator and output to the analyzing instrument repeatedly until a change in concentration was observed, measured using infrared spectroscopy. Flow rates of 11, 16, and 21 L/min were tested to observe the impact of flow rate on depletion; concentrations ranging from 0.02 to 0.40 BrAC were tested to measure the impact of initial concentration on depletion. It was found that when observing different flow rates, the depletion of ethanol concentration was directly correlated to the total liters of air that passed through the system (r > -0.95). Altering initial concentrations showed that as the solution concentration increased, the rate of depletion of ethanol also increased. Our findings indicate that the total ethanol depletion in a non-recirculating system breath alcohol simulator can be described as a percentage of the original concentration being lost when a specific volume of air is passed through the system. We then calculated an equation that can predict ethanol concentration in the solution after repeated testing.

Forensic facial examinations (FFE) primarily relies on manual image examination by trained experts using standardized protocols to identify suspects through detailed comparisons. In contrast, automated facial recognition (AFR) employs machine learning and AI algorithms to generate match scores between faces, producing ranked lists of potential suspects within a given population. In both these approaches, final identification decisions must still be validated and justified by qualified practitioners to ensure legal accountability and court admissibility. This study presents an innovative FFE workflow based on the output of AFR and empowered by the use of a Bayesian statistical software tool based on kernel density estimation (KDE) for likelihood ratio (LR) calculation, demonstrated through a case study conducted with the Carabinieri Investigation Department. The methodology is based on (1) the generation of match scores between facial images using automated software, (2) the calculation of LRs through statistical modeling against reference population data, (3) Tippett Plot validation aligned with ENFSI (European Network of Forensic Science Institutes) guidelines to demonstrate model accuracy to ensure forensic reliability beyond mere LR calculation. The proposed framework provides court-admissible statistical results for facial comparisons while maintaining practitioner oversight. This methodological approach can support forensic practitioners in the courtroom with a statistical result related to the use of AFR tools. This methodology has been shared with ENFSI experts in facial comparison.

When human remains are in an advanced stage of decomposition, drug concentrations are altered. In five decedents morphine, morphine-3-glucuronide (M3G), and morphine-6-glucuronide (M6G) concentration changes and bacterial DNA were investigated after 13 weeks of burial. Femoral blood (FB), musculus quadriceps femoris (QM), adipose tissue (AT), synovial fluid (SF), and vitreous humor (VH) were collected on arrival at the morgue (t1), 15-24 h later (t2), and after burial of 13 weeks (t3). At t3 FB, QM, AT, and BM were sampled during autopsy, along with additional samples. Morphine, M3G, and M6G concentrations were determined. The median morphine concentration change, expressed as t2/t1 ratios in FB, VH, SF, QM, and AT was 0.96 (0.87->1.1), 1.1 (0.90-1.2), 0.92 (0.86-1.02), 1.1 (0.90-1.6), and 1.4 (1.2-1.8), respectively. At t3 the concentrations showed wide variability, with the least in QM. The median(range) morphine to FB (t1) ratios in matrices collected at t3 from the torso (central) and outside the torso (peripheral) were 4.8 (1.0-70) and 1.3 (0.02->3.1), respectively, and were significantly different. The central and peripheral median M3G to morphine t3/t1 ratios were 0.31 (0.01-1.2) and 1.4 (range 0.34-13), respectively, suggesting postmortem deconjugation of M3G. Bacterial DNA was detected in all matrices. At t3 most matrices examined had a higher bacterial DNA concentration compared to t1. The measured t2/t1 morphine ratios suggest stability of morphine concentrations between t1 and t2. At t3 morphine concentrations in peripheral matrices are lower than in central matrices, where QM and BT are possible alternatives to analyze at extended PMIs.

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.

Ecstasy tablets are commonly associated with 3,4-methylenedioxy-methamphetamine (MDMA), but they often contain diverse psychoactive substances, including new psychoactive substances (NPS), which pose significant risks to users due to unknown composition and effects. This study analyzed 150 Ecstasy tablets seized in Poland between 2020 and 2021, shaped as "Stormtrooper" heads, to identify their chemical composition. Using gas chromatography-mass spectrometry (GC-MS) and ultra-high-performance liquid chromatography with photodiode array detection (UHPLC-PDA), we detected MDMA, 3,4-methylenedioxyamphetamine (MDA), and for the first time in Polish seizures, a novel phenylethylamine derivative-3,4-methylenedioxy-N,N-dimethylamphetamine (MDDM). MDDM, a methyl analogue of MDMA and dimethyl analogue of MDA, has limited pharmacological data and reportedly mild psychoactive effects. Its presence is likely linked to impurities or by-products formed during illicit MDMA synthesis. Quantitative analysis revealed that MDA occurred in the highest concentrations per tablet (26-74 mg), followed by MDDM (11-28 mg) and MDMA (3-11 mg). Although MDDM alone is considered to have low potency, its co-occurrence with other phenylethylamines may produce synergistic effects, potentially increasing toxicity. These findings shed light on synthetic routes in illicit MDMA production and highlight the unpredictable chemical composition of street drugs. The detection of multiple active substances-even at low doses-raises significant public health concerns, highlighting the necessity for continuous forensic monitoring and increased awareness of the dynamic and complex nature of synthetic drug markets.

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.

This technical note addresses forensic challenges in analyzing how images are embedded and represented within Portable Document Format (PDF) files. It was developed to support forensic practitioners-particularly those engaged in digital image analysis-in interpreting embedded image structures through hex-level inspection and format-specification-aligned analysis. Exploratory testing was conducted using hex editors and JSON-generated structure reports to examine internal PDF components, object models, and syntax in accordance with International Organization for Standardization (ISO) PDF standards. Embedding behaviors were analyzed across common image formats and insertion methods using Adobe Acrobat and LibreOffice Draw. The study identified a modular taxonomy of embedded image types and software-specific behaviors, revealing consistent internal structures with subtle variations in object placement and metadata retention. GIF-derived embeddings exhibited palette-based encoding and transparency features requiring specialized verification. This technical note introduces foundational methods for object-level interpretation of embedded image structures in PDFs, supporting examiner-led validation and reproducible structural comparison. Future work will extend these observations through broader sampling and quantitative assessment. The work aligns with priorities identified by the Video/Image Technology and Analysis (VITAL) subcommittee of the Organization of Scientific Area Committees for Forensic Science (OSAC), which called for improved understanding of PDF image lifecycle integrity.

In the context of criminal investigations, latent fingermarks play a pivotal role in obtaining clues related to suspects. Presently, various physical, chemical, and optical methods are employed for latent fingermark detection. However, it is observed that when utilizing physical and chemical techniques, latent fingermarks may sometimes suffer damage during the extraction process. Consequently, the importance of optical methods such as spectroscopy, ATR-FTIR, and MICRO XRF, which are comparatively less destructive, has been on the rise these days. This study aimed to evaluate the applicability of MICRO XRF for detecting both natural and artificial latent fingermarks on porous paper surfaces. Natural latent fingermarks were deposited by five donors after handwashing, while artificial latent fingermarks were produced by printing an artificial fingermark solution. MICRO XRF successfully captured elemental signals, with chlorine and potassium providing the clearest images for natural fingermarks and chlorine for artificial fingermarks. These findings demonstrate the potential of MICRO XRF to image latent fingermarks nondestructively regardless of background color. This work lays the foundation for further research to refine artificial formulations, optimize acquisition parameters, making it a promising choice for prioritizing latent fingermark detection methods.

Sexual dysfunction is a health issue that significantly affects adults. However, the increased demand for pharmacological treatments, such as sildenafil, tadalafil, and vardenafil has led to the emergence of counterfeit drugs, posing a serious public health concern. These counterfeit drugs and their analogs often lack clinical validation, leaving their effects on the human body largely unknown. In this case study, a suspected novel vardenafil analogue adulterated in sexual enhancement capsules was identified using gas chromatography-mass spectrometry (GC-MS). High-resolution mass spectrometry (LC-HRMS) was employed to determine the protonated molecular ion at m/z 562.2438 for the compound, and its possible elemental compositions were predicted. Based on AI-assisted analysis using ChatGPT-4o, the compound was inferred to be KD-027 (SLx-2101), a potential phosphodiesterase type 5 (PDE5) inhibitor. Following purification by column chromatography, nuclear magnetic resonance (NMR) spectroscopy confirmed this structure. In addition, evidence of coexisting E/Z tautomerism of KD-027 was observed in the NMR data. To the best of our knowledge, this is the first report to identify KD-027 in sexual enhancement products, providing its characteristic mass spectral fragments and NMR data, and demonstrating the utility of ChatGPT-4o in forensic investigations.