Forensic Sci., Volume 4, Issue 3 (September 2024) – 13 articles

Human urine and its detection are of interest in forensic studies in numerous contexts. Both crystalline urea and 1.0 M solutions of urea, as synthetic analog endmember components of human urine, were investigated as a proof-of-concept study to determine if detailed lab spectroscopy would be viable. Urea was reliably detected on Ottawa sand at concentrations of approximately 3.2% in dried experiments. Urea was detectable after 1 week of solution evaporation under lab conditions, at 9.65 wt.% 1 M solution. This investigation successfully establishes urea as a material of interest for reflective spectroscopy and hyperspectral remote sensing/image spectroscopy on a wide range of spatial scales, from specific centimeter-scale areas in a crime scene to searching large outdoor regions > 1 km². In addition, this investigation is relevant to improving the monitoring of human trafficking, status and condition of refugee camps, and monitoring sewage. Full article

Amyloidosis is defined as a rare group of 30 protein-folding diseases characterized by the extracellular deposition of a specific soluble precursor protein that aggregates in the form of insoluble fibrils. The gastrointestinal tract (GI) is a common site for amyloid deposits: Among patients with systemic amyloidosis, at least 70% present with gastrointestinal deposition. Rarely, the deposition is exclusively localized in this area, leading to various gastrointestinal symptoms (bleeding, weight loss, etc.). In this case report, we present a rare and unusual form of localized gastrointestinal amyloidosis, diagnosed after a post-mortem examination of an 83-year-old woman who died due to septic shock resulting from post-colonoscopy iatrogenic perforation of the sigma, in a suspected medical liability case. Morphological examination revealed AL amyloid deposits within the muscular wall of the submucosal vessels of the rectum, which caused increased friability of the vessels and ischemic changes in the intestinal mucosa. A renal cell carcinoma (RCC) was found, which might be related to amyloid deposits, as reported by the literature. Amyloid deposits are an unknown and unpredictable pathological substrate that increase the risk of iatrogenic perforation. Analysis of the medical documentation did not reveal any censurable conduct in terms of prescribing the procedure, technical execution, or subsequent management of the patient following the perforation. GI amyloidosis should be part of the risk stratification of patients with rectal bleeding and gastrointestinal symptoms, and awareness is essential to guide subsequent diagnostic and therapeutic approaches and investigate underlying causes. Full article

Continuous probabilistic genotyping (PG) provides a means to estimate the probative value of DNA mixtures tendered as evidence in court and subject to alternative propositions about the contributors to the mixtures. The weight of that evidence, however, may be valued differently, depending on which forensic laboratory undertook the DNA analysis. There is a need, therefore, to have a means for the comparison of likelihood ratios (LRs) generated by continuous PG amongst different laboratories for the same initial DNA sample. Such a comparison would enable the courts and the public to make judgements about the reliability of this type of evidence. There are particular mixtures and methods for which such a comparison is meaningful, and this study explores them for the short tandem repeat (STR) electropherograms of two-person mixtures obtained from the PROVEDIt Database. We demonstrate a common maximum attainable LR for a given set of common STR loci and a given DNA mixture that is consistent across three different STR profiling assays and two different capillary electrophoresis instruments. Full article

Urinary bladder diverticula are formed by the herniation of the mucosa into the muscle layer of the bladder wall, often ending with a narrow neck that communicates with the bladder lumen. They may be congenital or acquired, and they most often affect males. Urinary bladder diverticula discovery during autopsy incidence described in the literature is approximately 5–10%. Various causative factors have been described, including urinary tract obstruction (e.g., benign prostate hyperplasia) and neurogenic and iatrogenic causes. The most described site of occurrence is adjacent to the ureteral orifice. Their clinical presentation does not often facilitate diagnosis, as most are small and asymptomatic. Complications of urinary bladder diverticulosis include infections, lithiasis, neoplasia, pressure on adjacent tissues, obstruction, and rupture. Indeed, urinary bladder diverticula may lead to spontaneous bladder rupture in extremely rare cases. This paper presents the case of an 87-year-old female suffering from atrial fibrillation and under anticoagulant therapy who was pronounced dead in a hospital and was subsequently referred to our department for medico-legal examination. Upon macroscopic examination of the body, intra-abdominal hemorrhage was observed in the vicinity of the urinary bladder, extraperitoneally. A meticulous examination excluded the possibility of injury as the cause of this finding, and tissue samples were collected for histopathological examination. A ruptured urinary diverticulum was discovered and confirmed histopathologically. Death was attributed to intra-abdominal hemorrhage after rupture of urinary bladder diverticulum. A forensic pathologist should be aware of this diagnosis, as although extremely rare, such pathology may lead to death, especially when the patient is under anticoagulant therapy. Full article

As known in forensics, heat stroke deaths diagnosis is made by exclusion. In fact, in heat-related deaths, the gross and histologic postmortem findings are not pathognomonic, and biochemical investigations are not specific. Therefore, in such cases, a detailed examination of the circumstantial data and autopsied findings is necessary to exclude other possible causes of death. A case of fatal heat stroke of an elderly woman is reported. This case was diagnosed by examining the above elements in combination with immunohistochemical detection of heat shock proteins (HSPs). We then performed a narrative review of the literature on the subject to compare our case with similar ones. In view of the diagnostic complexity of heat-related deaths, we consider it essential to outline the state of the art on this topic. Our results may be a useful tool to orient forensic investigations into these types of deaths. Full article

Blow flies (Diptera: Calliphoridae) can be used in forensic entomology to provide information, including an estimate of the time of colonization and minimum postmortem interval, based on insect development. This study examined the development of third instar Calliphora terraenovae Macquart in four substrates: pine shavings, soil, sand, and clay. Pupation time, survival to adult, and wing vein length were measured to examine the substrate influence. There was a significant difference in the time to pupation (F_3,36 = 11.87, p < 0.0001) and the number of flies that eclosed (F_3,36 = 4.716, p = 0.007) among the substrates. Blow flies pupated faster in pine shavings and eclosed as adult flies faster in sand than in other substrates. Adults eclosed in the sand in 21.9 days, followed by pine shavings (22.8), clay (24.2), and soil (26.6). Although overall survivorship was low (10–46%), the greatest number of flies eclosed in sand, and the fewest in clay. Understanding the factors that impact blow fly development can help forensic entomologists improve rearing protocols and apply this information to death investigations, especially in cases with buried remains. Full article

This suspect case focuses on investigating the presence of halite (NaCl) crystals on the clothing of a deceased individual to determine whether they resulted from immersion in seawater or residual absorption after immersion (i.e., the crystals were left on the clothing after contact with the victim’s wet body). Thirteen clothing samples were collected from various garments worn by the victim and were subjected to optical stereomicroscopy, Scanning Electron Microscopy (SEM), coupled with Energy Dispersive Spectroscopy (EDS), and Simultaneous Thermal Analysis (STA). Optical stereomicroscopy revealed numerous white-colored, vitreous, and greasy luster microcrystals dispersed between fabric fibers, with higher concentrations observed near the hem seams and metal rivets. These microcrystals exhibited predominantly cubic and irregular morphologies. Additionally, sandy particles and organic elements, such as plant fragments and micro seashells, were detected, indicative of coastal environment exposure. SEM-EDS analysis confirmed the presence mainly of sodium and chlorine in stoichiometric ratios consistent with halite, with crystals exhibiting amorphous, needle-shaped, or cubic morphologies. Furthermore, STA analysis identified weight loss events attributed to organic decomposition and halite decomposition at high temperatures, corroborating SEM-EDS findings. The distribution and characteristics of halite crystals, along with other trace elements, support the hypothesis of immersion in seawater while wearing clothing. Specifically, the higher concentrations of halite crystals near thicker fabric portions and metal rivets suggest slower drying rates and longer evaporation times, indicative of immersion rather than residual absorption after swimming. This finding not only helps in determining the victim’s exposure to seawater but also establishes a methodology for distinguishing between different sources of halite residue on clothing. Overall, the comprehensive mineralogical characterization of halite crystals on clothing samples, using best practices of forensic mineralogy, provides valuable forensic insights related to the circumstances that led to the victim’s death. This approach aided investigators in reconstructing the sequence of events, enhancing the accuracy of forensic reconstructions. Moreover, this study contributes to the broader field of forensic geoscience by demonstrating the practical applications of mineralogical analysis in criminal investigations, potentially guiding future research and improving investigative techniques in similar cases. Full article

A female dog had allegedly been alive one day before its death. The veterinary office thought about accusing the dog’s owner for animal cruelty and commissioned forensic entomological expertise for the calculation of the time of insect colonization on the dog’s body. The statement of the dog’s owner was proven false by us on the grounds of (a) the advanced state of decomposition and (b) the minimal developmental time of fly larvae found on the dog’s body. The darkening and deformation of the fly maggots as well as insufficient temperature data made case work trickier than usual. We worked through the case by creating forensic entomological temperature scenarios. The court used the entomological evidence and issued a penalty order. Full article

Background: The concept of comparing “chronological age” vs. that of “dental age” has been well documented. Considering ethnic variations in dental development, the use of population-specific standards for age estimation has been emphasized. Mandibular maturity markers have been successfully employed to estimate the age of a person at the 18-year threshold. No such data are available for the Chinese population, which represents around one-fifth of the global human population. Aim: The aim of this research project was to analyze and grade mandibular third molars using maturity markers in the Chinese population. Materials and Methods: In total, 882 panoramic radiographs (424 females and 458 males) of 16- to 24-year-old Chinese children and young adults were obtained from patient archives. All patients were graded by a trained and calibrated examiner using stages A-D for mandibular maturity markers including Periodontal Ligament Visibility (PLV) and Root Pulp Volume (RPV). Results: The average Age at Assessment (AaA) ranged from 18.79 years for females in Stage A of PLV to 21.59 years for females in Stage D of PLV. The AaA was not statistically significant between females and males across all the stages, for both PLV and RPV. For PLV, the percentage of females below 18 years was 57.14% in Stage A and 17.14% in Stage D. For males, it was 48.84% in Stage A and 14.93% in Stage D. For RPV, the percentage of females below 18 years was 54.72% in Stage A and 12.73% in Stage D. For males, it was 49.09% in Stage A and 14.81% in Stage D. On average, for PLV, 85.30% of subjects were over 18 years of age in Stages C and D, and for RPV, 82.50% subjects were over 18 years of age in Stages C and D. Conclusions: Both RPV and PLV are considered as reliable maturity markers to estimate the age of Chinese subjects in the 18-year threshold. No difference was observed in the average Age at Assessment of mandibular maturity stages between the sexes. Full article

The revolutionary breakthroughs in Machine Learning (ML) and Artificial Intelligence (AI) are extensively being harnessed across a diverse range of domains, e.g., forensic science, healthcare, virtual assistants, cybersecurity, and robotics. On the flip side, they can also be exploited for negative purposes, like producing authentic-looking fake news that propagates misinformation and diminishes public trust. Deepfakes pertain to audio or visual multimedia contents that have been artificially synthesized or digitally modified through the application of deep neural networks. Deepfakes can be employed for benign purposes (e.g., refinement of face pictures for optimal magazine cover quality) or malicious intentions (e.g., superimposing faces onto explicit image/video to harm individuals producing fake audio recordings of public figures making inflammatory statements to damage their reputation). With mobile devices and user-friendly audio and visual editing tools at hand, even non-experts can effortlessly craft intricate deepfakes and digitally altered audio and facial features. This presents challenges to contemporary computer forensic tools and human examiners, including common individuals and digital forensic investigators. There is a perpetual battle between attackers armed with deepfake generators and defenders utilizing deepfake detectors. This paper first comprehensively reviews existing image, video, and audio deepfake databases with the aim of propelling next-generation deepfake detectors for enhanced accuracy, generalization, robustness, and explainability. Then, the paper delves deeply into open challenges and potential avenues for research in the audio and video deepfake generation and mitigation field. The aspiration for this article is to complement prior studies and assist newcomers, researchers, engineers, and practitioners in gaining a deeper understanding and in the development of innovative deepfake technologies. Full article

Complex suicides refer to using two or more suicide modes. In the literature, complex suicides are distinguished into planned and unplanned. Using multiple methods is related to ensuring a fatal result or because the first method appears too painful, time-consuming, or ineffective. The review aims to provide an overview of the critical features of complex suicides in the forensic context. The review was conducted by searching online databases (PubMed Central and Scopus) up to March 2023. We identified 52 articles that met the inclusion criteria, describing 261 cases. Suicides were classified as planned in 136 cases (52.1%); 105 cases (40.2%) were defined as unplanned, while in the remaining 20 cases (7.7%), the authors did not propose any classification. In 2/261 (0.8%) cases, four modes were indicated, three modes were observed in 34/261 cases (13%), and in 224/261 (85.8%) cases the suicides were carried out using a combination of two distinct methods. The method most frequently employed in the first instance in unplanned suicides were sharp-force injuries and stabbing, followed by mechanical asphyxia (hanging, self-strangulation, plastic bag suffocation) and a fall from height. Regarding planned suicide, the most frequent suicide methods were asphyxia, intoxication (drugs, substances of abuse, or alcohol), and poisoning via toxic substances. Complex suicides represent a relatively rare entity in forensic pathology; nevertheless, they can be challenging for the forensic pathologist in terms of differential diagnosis compared to homicides, due to the sometimes multifaceted presentation. Full article

Background: Violence against women or other vulnerable individuals is a serious violation of human rights and a global public health issue representing a significant “problem of enormous global health proportions”. Violence against women is an endemic phenomenon; the numbers are very high, highlighting the severity and urgency of the problem. Methods: We conducted this research by examining the field of violence against women. Our analysis involved reviewing papers published between 2018 and December 2023, which were identified through electronic database searches. Out of a total of 136 papers initially identified, we considered 71 documents. Results: This research highlights the global nature of violence against women, including psychological assessments of harm, as a socio-cultural problem and underlines the more common injuries. Conclusions: We examined how the presence of forensic experts can be beneficial in identifying and evaluating injuries, as well as reconstructing the dynamics of the events, particularly for judicial purposes. Full article

Fire deaths present several diagnostic challenges for the forensic examiner, the most significant of which is the identification of the cause of death and the evaluation of the morphological consequences of heat injuries in the ante-mortem and post-mortem periods. Here, we describe the case of two young lovers found dead inside a travelling carousel destroyed by a fire. Circumstantial evidence of disputes between families running the town fair raised the suspicion of intentional arson. Comparative analysis of crime scene investigation, radiological, autoptic, histological, and toxicological findings revealed signs of vitality (i.e., presence of soot deposits inside the respiratory and digestive tracts, heat damage to the respiratory mucosa) and identified fatal asphyxia from haemorrhagic pulmonary oedema as the cause of death. Since the experimental burning of plastic samples collected from a similar carousel demonstrated the significant production of phosgene, the death of the two lovers was attributed to the probable inhalation of this gas. The case presented here underlines the importance of a multidisciplinary approach of any fire-related death, providing an insight into circumstantial and forensic (autopsy, toxicological, and immunohistopathological) elements useful in raising suspicion of possible toxic gas inhalation. In the presence of high levels of PVC materials at the fire scene and pulmonary oedema at the autopsy, with no alternative causes of death, the forensic pathologist must suspect a fatal exposure to phosgene. Full article