Journal of forensic sciences最新文献

The collection, storage, and transport of samples prior to and during analysis is of utmost importance, especially for highly potent analogs that may not be present in high concentrations and are susceptible to pH or thermally mediated degradation. An accelerated stability study was performed on 17 fentanyl analogs (fentalogs) over a wide range of pH (2–10) and temperature (20–60°C) conditions over 24 h. Dilute aqueous systems were used to investigate temperature and pH-dependent kinetics using liquid chromatography–tandem mass spectrometry (LC–MS/MS). Liquid chromatography-quadrupole/time-of-flight-mass spectrometry (LC-Q/TOF–MS) was used for structural elucidation of degradants. With the exception of remifentanil, all fentalogs evaluated were stable at pH 6 or lower. Fentalogs were generally unstable in strongly alkaline environments and at elevated temperatures. Remifentanil was the least stable drug and N-dealkylated fentalogs were the most stable. Fentanyl degraded to acetylfentanyl, norfentanyl, fentanyl N-oxide, and 1-phenethylpyridinium salt (1-PEP). A total of 26 unique breakdown products were observed for 15 of the fentanyl derivatives studied. Common degradation pathways involved N-dealkylation, oxidation of the piperidine nitrogen, and β-elimination of N-phenylpropanamide followed by oxidation/dehydration of the piperidine ring. Ester and amide hydrolysis, demethylation at the propanamide, and O-demethylation were observed for selected fentalogs only. The potential for analyte loss should be considered during the pre-analytical phase (i.e., shipping and transport) where environmental conditions may not be controlled, as well as during the analysis itself.

Geometric morphometrics (GMM) have been applied to understand morphological variation in biological structures. However, research studying cortical bone through geometric histomorphometrics (GHMM) is scarce. This research aims to develop a landmark-based GHMM protocol to depict osteonal shape variation in the femoral diaphysis, exploring the role of age and biomechanics in bone microstructure. Proximal, midshaft, and distal anatomical segments from the femoral diaphysis of six individuals were assessed, with 864 secondary intact osteons from eight periosteal sampling areas being manually landmarked. Observer error was tested using Procrustes ANOVA. Average osteonal shape and anatomical segment-specific variation were explored using principal component analysis. Osteon shape differences between segments were examined using canonical variate analysis (CVA). Sex differences were assessed through Procrustes ANOVA and discriminant function analysis (DFA). The impact of osteonal size on osteonal shape was investigated. High repeatability and reproducibility in osteon shape landmarking were reported. The average osteon shape captured was an elliptical structure, with PC1 reflecting more circular osteons. Significant differences in osteon shape were observed between proximal and distal segments according to CVA. Osteon shape differed between males and females, with DFA showing 52% cross-validation accuracies. No effect of size on shape was reported. Osteonal shape variation observed in this study might be explained by the elderly nature of the sample as well as biomechanical and physiological mechanisms playing different roles along the femoral diaphysis. Although a larger sample is needed to corroborate these findings, this study contributes to the best of our knowledge on human microanatomy, proposing a novel GHMM approach.

Cannabis is one of the most consumed illicit drugs and the potency of cannabis products is of note due to health-related concerns. Hand-rubbed hashish is the ancient technique of extracting psychoactive resin from cannabis plants and is practiced in the Indian Himalayas. This study establishes the cannabinoid profile and potency of hand-rubbed hashish collected from 20 regions of the northwest Himalayas. Fifty-eight hashish samples were analyzed using a validated high-performance liquid chromatography-diode array detection (HPLC-DAD) method. Ten cannabinoids were quantified including acidic (THCA & CBDA), and neutral compounds (CBDV, THCV, CBD, CBG, CBN, Δ⁹-THC, Δ⁸-THC, and CBC). The mean concentration (w/w%) of Δ⁹-THC is 26%; THCA is 15% and THC_Total is 40% is observed in the studied hashish samples. The majority (70%) of the hashish samples were categorized in chemotype I with the THC:CBD:CBN ratio of 91:3:4, and the remaining 30% were categorized under chemotype II with the ratio of 76:15:8. Diverse qualities of hashish are produced in the studied regions as per the seed, plant selection, and skills of manual rubbing, which results in potency variations. The average difference between the least and highest potent hand-rubbed hashish of a region is 27 w/w% (THC_Total). The other studied non-psychoactive cannabinoids have a mean w/w% of <5%, followed by 6% of CBDA. It is concluded that the cultivated and wild cannabis fields in the northwest Himalayas belong to the drug-type cannabis subspecies. Hand-rubbed hashish holds traditional significance and impacts the current policies of legislation.

Opium poppy, coca and cannabis are raw materials for three notorious illicit drugs. For a long time, drug lords have been growing and smuggling these drugs in a variety of ways and channels and are continually finding new ways of trafficking their wares, which has led to the increasing difficulty of global drug enforcement. In the present paper, we propose an innovative pollen identification system for these important drug plants, which provides a tool for screening and detection of the drugs to aid in drug enforcement. By utilizing the characteristics of these fine particles, their abundant production, and high resistance to decay, we believe this tool could be applied in the following scenarios: detecting and dynamically monitoring drug cultivation activities; determining whether a suspect has been to fields of drug plants and determining whether the site has ever been planted with a drug plant and/or was involved in drug production. In the future, combined with microscope automatic image acquisition technology and intelligent image recognition technology, this pollen identification system is expected to be used to screen three notorious illicit drug plants, thus enhancing the efficiency of drug related crime investigations.

During an investigation using Forensic Investigative Genetic Genealogy, which is a novel approach for solving violent crimes and identifying human remains, reference testing—when law enforcement requests a DNA sample from a person in a partially constructed family tree—is sometimes used when an investigation has stalled. Because the people considered for a reference test have not opted in to allow law enforcement to use their DNA profile in this way, reference testing is viewed by many as an invasion of privacy and by some as unethical. We generalize an existing mathematical optimization model of the genealogy process by incorporating the option of reference testing. Using simulated versions of 17 DNA Doe Project cases, we find that reference testing can solve cases more quickly (although many reference tests are required to substantially hasten the investigative process), but only rarely (<1%) solves cases that cannot otherwise be solved. Through a mixture of mathematical and computational analysis, we find that the most desirable people to test are at the bottom of a path descending from an ancestral couple that is most likely to be related to the target. We also characterize the rare cases where reference testing is necessary for solving the case: when there is only one descending path from an ancestral couple, which precludes the possibility of identifying an intersection (e.g., marriage) between two descendants of two different ancestral couples.

Thermocouples are utilized to monitor a wide range of temperatures in industrial applications. They are also used in both fire and forensic science research to measure temperatures of fires and of materials exposed to fire. Taking accurate temperature measurements during forensic fire-death scenarios is very difficult due to direct fire exposure to thermocouples, shrinkage and destruction of tissues, and movements from pyre collapse and pugilistic posturing of human donors. This two-part study investigates the impacts on the accuracy of temperature data if the selected thermocouples are unable to withstand fire exposure. Part I (this article) provides an overview of thermocouple theory along with evidence of the physical deterioration that occurs when glass fiber-insulated thermocouple wires are overheated by exposure to fire-level temperatures in a muffle furnace. This study verified that insulation overheating causes embrittlement and disintegration, which can cause the indicated temperature to reflect a new location of measurement located far away from the original measuring junction at the thermocouple tip. Part II will discuss the measurement errors that occurred due to low electrical resistance of insulation when three different thermocouple models were passed through fire-level temperatures to measure an ice bath at a constant temperature of 0°C.

Part II of this two-part article investigates the impact of thermocouple insulation failure on temperature measurement data in forensic fire-death scenarios. Two different models of glass fiber-insulated thermocouple wires (GG-K-24-SLE and HH-K-24 from Omega Engineering) were passed through a ceramic kiln at temperatures up to 1093°C to measure an ice bath at a constant 0°C. In a separate experiment, the same two models of thermocouple wire plus a BLMI-XL-K-18U-120 mineral-insulated metal-sheathed thermocouple probe were passed through a wood pallet fire to measure an ice bath. In the ceramic kiln, the effect on measurement errors was determined for short vs. long exposure lengths and clean insulation vs. insulation contaminated with pork fat. Glass fiber-insulated thermocouple wires showed severe failure in both experiments, with errors ranging from −270°C to almost 2200°C. The metal-sheathed probe showed no evidence of insulation failure and continued to accurately measure the ice bath temperature within expected margins of error around 0°C. This study highlights how exposure of inadequate thermocouples to fire-level temperatures produces severe errors in temperature data. Consequently, it will not be possible to use this data to draw any accurate conclusions about the effects of fire exposure to human donors or animal proxies.

Monson KL, Smith ES, Peters EM. Accuracy of comparisons conducted by forensic firearms examiners. J Forensic Sci. 2023;68(1):86–100. https://doi.org/10.1111/1556-4029.15152

This communication corrects two inadvertent errors. The denominator of Equation 2 (page 89 of the publication) contains an extra value (848), although the stated result (2.92%) is correct. The corrected equation is:

The first paragraph on page 91 of the publication, which refers to Figure 5, is also revised as follows:

Examples of comparisons that resulted in false-positive errors are provided in Figures 3 (bullets), 4 (cartridge cases), and 5 (bullets). An example of a comparison that resulted in a false-negative error is provided in Figure 6 (cartridge cases). In addition to exemplifying erroneous conclusions, Figures 3–6 illustrate the difficulty level of many of the comparisons in this study.

We apologize for any convenience resulting from these oversights.

Identification of vascular injuries is crucial for complete postmortem evaluation and understanding of trauma deaths by the Medical Examiner. Some vascular injuries are difficult to evaluate due to challenging anatomic locations, especially in the head and neck. Documenting injuries of the facial and vertebral arteries is challenging and necessitates time-consuming dissections that can create artifacts and disfigurement. In busy medical examiner offices with a significant number of traumatic injuries, finding a creative solution to employ reliable postmortem angiography is desirable. At the Office of the Chief Medical Examiner for the State of Maryland (OCME), we created and effectively implemented a selective angiography procedure using traditional indwelling Foley catheters and water-soluble barium swallow contrast to evaluate arterial injuries using either digital radiography or computed tomography imaging modalities. This technique and imaging interpretation can be performed by a medical examiner or forensic pathology fellow after basic technical training and basic radiology training. This study outlines the technique, methods, and utilization of the procedure and describes the findings of six deaths due to vascular lesions from different injury mechanisms and disease processes and describes the ease of implementation on a broader scale in busy Medical Examiner's offices.