Forensic Science, Medicine and Pathology最新文献

Forensic genetics faces significant challenges in the evolving landscape of DNA mixture analysis. This paper highlights the complexities associated with stochastic effects and artifacts in degraded or low-quantity samples and explores the primary objectives of DNA mixture analysis, namely deconvolution and weight of evidence quantification. The study examines the efficacy of the software tool EuroForMix (EFM) in interpreting complex mixtures. Genetic profiles from two forensic cases processed in 2022 by the Brazilian National Institute of Criminalistics' DNA Forensic Laboratory were reanalyzed using EFM v.3.4.0, focusing on deconvoluting DNA mixtures and quantifying the weight of evidence. Results were compared with previous analyses conducted using a laboratory-validated spreadsheet, LRmix Studio (for computing LR), and GeneMapperTM ID-X (for deconvoluting mixtures). EFM demonstrated high efficiency in both deconvolution and weight-of-evidence quantification, showing improved LR values for various profiles compared to previous analyses. In the reanalyzed cases, weight of evidence calculations using EFM produced values comparable to those obtained with the laboratory-validated spreadsheet and superior LR values compared to LRmix Studio. The comparison of deconvoluted profiles using EFM and GeneMapperTM ID-X revealed mostly consistent results for the major contributor genotype, with EFM yielding equal or better outcomes in most profiles. Thus, EFM shows potential as a tool for DNA mixture analysis, including both LR computation and deconvolution. Despite these encouraging results, it is recommended that each forensic laboratory develop DNA mixture interpretation protocols that consider internal validation.

Estimation of the postmortem interval (PMI) of found bones is an important and challenging part of forensic osteology assessments. This study examined human long bones that had been taken from cemeteries and hoarded by a "bone collector". Based on the police investigation and own investigation into the length of grave leases in the pertinent cemeteries, the narrowed down PMI for the bones was between 20 and 100 years. Our aim was to evaluate the suitability of the UV-fluorescence and luminol methods in determining the PMI of these bones and to assess the reliability of the results for forensic practice. Based on macroscopic criteria, 201 bones were classified into various PMI groups. Freshly sawn bone surfaces were then assessed with UV-fluorescence and luminol. The UV-fluorescence examination showed a weak to mediocre correlation between the intensity of UV-fluorescence and the PMI estimated by macroscopic criteria. Surprisingly, the luminol test did not reveal a negative correlation between the degree of chemiluminescence and macroscopically estimated PMI. Within a PMI span of up to 100 years, the extent of UV-fluorescence can serve only as a rough indicator of PMI. Alone, the method does not suffice to identify forensically relevant PMIs. Likewise, the luminol test does not reliably distinguish between bone finds with and without forensically relevant PMI. Nonetheless, the assumption that a negative luminol-test still speaks for a historical find appears to be justified, and, at least in combination with other tests, the luminol test can be used.

This study aimed to develop and validate two simplified, one-step extraction methods coupled with liquid chromatography-tandem mass spectrometry (LC-MS/MS) for the simultaneous segmental analysis of psychoactive substances, specifically doxylamine (DOX), haloperidol (HAL), citalopram (CTP), sildenafil (SDF), and common illicit drugs in hair samples. A secondary objective was to apply these methods to a real-life forensic case involving suspected prolonged drug-facilitated crime (DFC) with suspected non-consensual exposure with financial implications.Two analytical methods based on one-step extraction protocols coupled with LC-MS/MS were developed and validated according to ANSI/ASB 036 standards. One method was based on ultrasonic solvent extraction (USE), while the other relied on passive solvent incubation (PSI). Hair samples from two victims were collected and segmented to assess chronic drug exposure. Analytical performance was evaluated in terms of linearity, sensitivity, accuracy, precision, matrix effects, recovery, and dilution integrity.Both methods demonstrated high sensitivity (LODs as low as 0.27 pg/mg), accuracy (bias within ± 15%), and precision (RSD ≤ 18.3%). Segmental analysis of Victim A's hair revealed DOX and HAL concentrations consistent with chronic, non-consensual administration. HAL was also detected in Victim B's scalp and leg hair, while DOX was absent. The segmental distribution patterns supported the hypothesis of prolonged sedative non-consensual drug exposure.This study presented a rare case of drug-facilitated crime involving chronic administration of HAL and DOX within an alleged deception-based context. The validated LC-MS/MS methods proved to be robust, cost-effective, and suitable for routine forensic toxicology. Segmental hair analysis provided critical retrospective evidence, reinforcing its value in complex DFC investigations. The interpretation remained confined to analytical evidence, without inferring intent.

This case documents a rare occurrence of heterotopic mesenteric ossification (HMO) identified at autopsy, highlighting the long-term sequelae of prior abdominal trauma and expanding awareness of this uncommon entity in forensic pathology. HMO, also called intraabdominal myositis ossificans, is a subset of myositis ossificans traumatica and is characterized by the abnormal formation of osseous, cartilaginous, and sometimes bone marrow elements. It is generally associated with trauma or previous abdominal surgeries and can lead to potential life-threatening complications. Autopsy findings may highlight the presence of extensive ossified tissue formation in the mesentery, along with signs of the associated complications. Due to the rarity of these findings, the diagnosis at autopsy is challenging. In the present case report, the body of a 34-year-old Black male who died of multiple gunshot wounds was examined at the Cook County Medical Examiner's Office. He had a history of remote abdominal multiple gunshot wounds with subsequent exploratory laparotomy. During the post-mortem examination, dense fibrous adhesions were noted in the abdominal cavity and multiple fragments of ossified tissue were removed from the mesentery. The observed findings were suggestive of HMO. Radiological imaging can reveal early ossification within weeks of trauma, while histopathological analysis confirms the diagnosis, showing mature lamellar bone with minimal atypia. This case highlights the importance of recognizing and considering this rare entity in the differential diagnosis when no apparent causes of death are detected at autopsy.

The aim of the current study is to investigate if third molar agenesis is associated with dental maturity variations in Brazilian children. Radiographs of children from 10 to 15 years old were examined and patients with 32 teeth were included in the control group and patients with at least one third molar agenesis were included in the agenesis group. Demirjian's method was used to calculate dental age and evaluate dental maturity. Dental age was calculated using the Dental Age mobile app. The dental maturity was determined by calculating the difference between dental age and chronological age (DA-CA), in which positive, negative, and null values indicated advanced, delayed, or normal dental development, respectively. T test and ANOVA were used for comparisons. The Pearson correlation test was used to evaluate the relationship between chronological age and dental age (alpha = 5%). A total of 336 patients were included, 58 (17.3%) had at least one third molar agenesis. Third molar agenesis was associated with delayed dental maturity (p = 0.0294). Patients with 3 or 4 missing third molars had statistically significantly more delayed dental development compared with control patients (p = 0.0001) and patients with 1or 2 third molar agenesis (p = 0.0290). Individuals with third molar agenesis present delayed dental maturity. Our results also suggested that the number missing third molars are associated with the delayed maturity. Individuals with third molar agenesis showed delayed dental maturity, which was more pronounced in those missing three or four third molars. These findings suggest that the extent of agenesis is associated with the magnitude of maturational delay.

Forensic autopsies are crucial in determining the cause and mechanisms of death in community assault victims. Studies have shown that multiple blunt force injuries are the leading cause of death in community assault cases. Specifically, soft tissue hemorrhage plays a critical role in these fatal outcomes, often leading to hypovolemic shock due to extensive hemorrhage in the subcutaneous tissue. The use of Infrared (IR) photography has the potential to reduce the need for invasive procedures, such as extensive skin flaying during autopsies, while still accurately identifying the presence and extent of soft tissue injuries. This study aimed to evaluate the accuracy of IR photography in detecting the presence and the size of soft tissue hemorrhages in community assault victims with Fitzpatrick V-VI skin types at Tygerberg Forensic Pathology Service Mortuary in Cape Town. Standard and IR photography were performed in each case, followed by flaying of the skin of the back and buttocks. The presence and the size of soft tissue hemorrhages were documented after the flaying of the skin. These findings were compared to the number and size of subcutaneous hemorrhages that were seen with IR photography. Findings revealed that while 102 contusions were noted on the back and buttocks after flaying of the skin; IR photography successfully identified 84 of these hemorrhages. Thus, infrared imaging visualized 82.4% of the injuries. The measurement of the size of the subcutaneous hemorrhages of the back and the buttocks with IR photography compared to measurements taken after flaying of the skin revealed an excellent agreement (CCC = 0.81 and 0.86, respectively). This study demonstrates that infrared photography is a valuable adjunct in detecting soft tissue hemorrhage in individuals with Fitzpatrick skin types V to VI. We have learned that IR can enhance pattern recognition in bruises It cannot, however, replace skin flaying as extensive areas of subcutaneous hemorrhages remain hidden with intact skin, even with IR photography.

Firearm suicides typically involve a single weapon and shot. Multiple gunshot suicides are rare, representing only 0-6% of all firearm suicides, with cases involving two weapons being exceptionally uncommon. We report an extraordinary suicide case involving an 86-year-old male with recently diagnosed bone cancer who used two revolvers to inflict three self-inflicted gunshots. The deceased was found in his bathroom, positioned on a mat with a pillow, holding a Taurus 85 0.38 Special revolver in his left hand and having used a Colt Python 0.357 Magnum revolver with his right hand. Two shots were fired simultaneously into the left chest from both weapons, followed by a third shot to the right thigh using the Colt Python. The scene suggested careful premeditation. Autopsy revealed severe bilateral lung damage, cardiac injury, and a through-and-through thigh wound. Both revolvers were functional and matched ballistic evidence. Gunshot residue consistent with both weapons was found on the deceased's hands, and his DNA was detected on both firearms. Notably, no fingerprints were recovered from either weapon, and no blood backspatter was observed on the hands-findings not uncommon in close-range self-inflicted gunshots. This case represents the first reported suicide involving three shots from two revolvers, including an unusual shot to the extremity. The absence of typical physical evidence (fingerprints, backspatter) initially complicated the investigation but is consistent with forensic literature. This case emphasizes the importance of comprehensive forensic investigation in complex suicides and contributes valuable data to the limited literature on multiple weapon suicides.