Forensic Sciences

Background: In forensic investigations, the postmortem interval (PMI) is still mainly determined using pathological analysis. There have been many scientific efforts to identify alternative methods of PMI determination, which may be applied to future forensic practices. Methods: Considering the ethical implications and the availability of tissue samples for PMI experiments, we used human blood samples stored at three temperatures to mimic different environmental conditions, testing them over a period of 10 days post-sampling. These samples were biochemically tested for specific blood biomarkers, glucose (Glu) and lactic acid (Lac), to determine their potential as PMI biomarkers. Then, a mixed-effect mathematical model was applied to the data related to time- and temperature-dependent concentration changes of both biomarkers followed by additional computer-simulated models to refine the PMI estimates based on each of the biomarker concentration changes. Results: Herein, we present this alternative method of PMI estimation based on the biochemical testing of blood samples that could potentially be collected at a crime scene using biochemical blood biomarkers Glu and Lac, which are mathematically modelled and refined with time- and temperature concentration changes. Conclusions: While there is still much forensic science required to validate any alternative PMI methods, this study shows that there are other cross-disciplinary methods of PMI determination that warrant further exploration. Full article

Contemporary human preservation technologies aim to preserve the structure of the body—and especially the brain—after legal death. Although it has not yet been demonstrated, some believe that this may act as a bridge to future medical technologies that could allow for the recovery of life, if this ever becomes feasible and humane. However, current death investigation practices impose two significant obstacles to high-quality preservation. The first and most common is ischemic delay—the period between legal death and initiation of preservation while the death is investigated, during which brain tissue progressively degrades. The second is involuntary autopsy, where tissue disruption can severely compromise preservation quality. Through analysis of legal precedents and the ethical principles of bodily autonomy, non-discrimination, and potential preservation of life, we argue that individuals should be allowed a way to prevent both ischemic delay and autopsy from affecting the quality of their preservation. We explore potential avenues to implement a right to immediate preservation, including administrative, legislative, and judicial approaches, aimed at balancing this right with the societal interest in performing death investigations. This narrative review has implications for individual autonomy, public policy, and the legal framework surrounding death investigation in the context of emerging preservation technologies. Full article

Background: The main objective of this study was to carry out an online questionnaire in order to assess dentists’ knowledge and perception of dental materials submitted to high temperatures, helping to clarify and raise awareness of possible gaps in the area of forensic dentistry, especially in human identification. Results: Out of a total of 272 respondents, there was a greater influx of responses from countries such as Portugal and Brazil, the majority being female (66.3%), with an average age of 39 years. Most dentists consider complete clinical records to be extremely important. In addition, professionals with less experience provide fewer models in releasing their clinical records. In the case of dental materials, dentists consider composite resin and glass ionomers to be more susceptible to changes in shape and colour, while amalgam is considered the most stable, followed by ceramic and metal-ceramic crowns. On the other hand, dentin is considered more susceptible to colour changes than enamel. Enamel is seen by most professionals as resistant, undergoing few changes in shape at high temperatures. Conclusions: The opinion of the surveyed dentists on this subject is broadly in line with the existing literature. The only observed differences were related to exposure time and enamel resistance, since they assume that enamel is more resistant, and dentin is more vulnerable. Full article

A novel method for the development of fingerprints in environmentally friendlier conditions and on porous surfaces with 1,8-diazafluoren-9-one (DFO) is reported herein. DFO, a fluorescent dye was formulated in glacial acetic acid, methanol, and a minimum amount of methylene chloride. The DFO reacted with amino acid components of latent prints, resulting in a fluorescent species that was visualized under daylight, UV light at 254 nm, 365 nm, and LED at 395–405 nm. The developed prints were photographed using iPhone 11 and IOS 17.4.1. The fluorescent spectra of the species resulting from DFO’s reaction with the amino acid glycine and the wavelengths of maximum excitation (λ_ex = 470 nm) and emission (λ_em = 585 nm) were also reported. The method is suitable for forensic laboratories. Full article

Miscarriages of justice led to concerns that forensic science reports were prosecution-biassed and led to elementary errors of probability. The European Network of Forensic Science Institutes (EFNSI) and other institutes developed standards requiring reporting of the probability of evidence under all hypotheses (usually prosecution and defence hypotheses) with the likelihood ratio (LR). $LR={\displaystyle \frac{p\left(E|H_p\right)}{p\left(E|H_d\right)}},$ values > 1, being probative for a prosecution hypothesis. In elementary two-variable conditional probability theory (Baye’s theorem), the LR is also an updating factor which multiplies the odds of guilt for each item of evidence considered. Although this is not true for multiple-variable probability theory, the value of the LR as a valid measure of evidential probity remains. Forensic scientists are experts in evidence and should not stray into the role of the Court to consider the probability of the hypotheses given the totality of the evidence: $p\left(H_p{,H}_d|,E_1,E_2\dots E_n\right).$ Medical experts may be required to assist the court with diagnoses (the hypothesis), but this privilege is balanced by vigilance that experts do not stray beyond their expertise. A narrow interpretation of expertise hinders the evaluation of the evidence under hypotheses adjacent to the area of expertise. This paradox may be overcome by experts declaring competence in areas adjacent to their main area of expertise. Regulatory bodies do not currently require medical experts to adhere to EFNSI guidelines in evaluative reporting. Legal opinion is divided on whether probability theory can be applied to cases requiring medical expertise. Medical experts should, in their reports, clearly separate evaluating the probability of the evidence (where evaluative reporting should apply) and evaluating the probability of hypotheses where methodology should be prioritised over opinion. The reckless misapplication of elementary probability theory, typically transposing conditional probabilities or neglecting prior odds, may lead to the jury being misled into believing posterior odds of guilt are many orders of magnitude greater than reality. Medical experts should declare training in elementary probability theory. Inaccurate probabilities are a joint enterprise between all who inform or advise the jury, so all must be trained in elementary probability theory. Full article

Teeth are highly durable and useful in forensic identification and studying the impact of environmental factors could aid forensic investigations. Accurate post-mortem interval (PMI) estimation using dental evidence is critical in legal contexts, it requires further exploration. Aims: This study included a scoping review investigating macroscopic and microscopic changes in teeth in various simulated environments (Part 1) and an experimental study assessing changes in teeth and restorations exposed to distilled water, saline water, acidic soil, and alkaline soil (Part 2). Methods: The scoping review analysed publications from five databases using keywords such as ‘Teeth’, ‘Dental’, ‘Water’, ‘Soil’, ‘Acid’, and ‘Forensic.’ The experimental study involved 40 human teeth photographed before and after a 90-day exposure period to record shade variations and macroscopic changes. Results: Part 1: Twenty-six relevant articles from 10 countries (1987–2022) were reviewed, with most focusing on human teeth (77%), unrestored teeth (54%), macroscopic changes (46%), and high-temperature environments (53%). Part 2: Teeth in distilled water (G1) showed no shade variation. In saline water (G2), 60% of teeth decreased in shade. In acidic soil (G3), 40% showed an increased shade, while 50% showed a decreased shade. In alkaline soil (G4), 70% of teeth showed an increased shade. Restorations exhibited minimal changes across environments. Conclusions: Studies on the macroscopic changes because of high temperature on teeth and dental restorative material are popular. Teeth exposed to alkaline and acidic soil showed the most changes in the structure. Full article

Background—Endomyocardial fibrosis (EMF) is a chronic restrictive cardiomyopathy endemic to tropical and subtropical regions, characterized by fibrotic thickening of the endocardium, predominantly affecting the ventricular chambers. As global migration increases, cases of EMF may emerge in non-endemic areas, posing a diagnostic challenge for healthcare professionals unfamiliar with this condition. Methods—We report the case of a 21-year-old man of African origin who experienced sudden collapse while residing in a reception center for asylum seekers in Apulia, Southeastern Italy. His medical history revealed that one week prior, he had been presented with high fever, chest pain, and asthenia, symptoms initially misinterpreted as influenza by a local physician, leading to antibiotic therapy. Results—The definitive diagnosis of EMF was established post-mortem through histological examination, which identified characteristic endocardial fibrosis. This case exemplifies the re-emergence of neglected tropical cardiac diseases in Western countries due to increased migration from endemic regions. Conclusions—This case highlights the need for heightened clinical awareness among healthcare professionals, particularly in cardiology and primary care, to recognize and manage geographically displaced diseases such as EMF. Implementing enhanced medical education and diagnostic protocols is essential to address the evolving epidemiological landscape and improve early identification of rare but significant cardiac pathologies in migrant populations. Full article

Background: The aging of fly larvae is primarily determined by their temperature-dependent growth rates, a concept widely applied in forensic entomology to estimate the minimum postmortem interval using the accumulated degree day/hour (ADD/ADH) method. Method: This study adapted the same approach for veterinary entomology, offering insights into how accumulated degree day (ADD) can be used to estimate both the number and timing of fly generations in nature. This study details a method for identifying the pupation landmarks of Ch. rufifacies (Macquart) by characterising seven distinct pupal stages over time. Following this, ADD values were calculated for each life stage using developmental data collected from two types of ovine muscle: muscle with fat and muscle without fat, at two temperatures: 24 ± 1 °C for autumn and 30 ± 1 °C for summer, reflecting typical seasonal conditions in southwestern Australia. Results: This study also provided a graphical illustration of how to estimate the number of fly generations emerging during a season, based on daily temperature data from autumn and summer in southwestern Australia for the 2023/2024 period. Conclusions: This approach highlights the value of developmental data and ADD methods in veterinary entomology, offering a robust framework for understanding fly population dynamics for effective myiasis control strategies. Full article

Forensic and medical examiners are often required to sample the body of a victim (either living or deceased), or a suspect of a criminal offence, for foreign DNA. This can provide useful information when the alleged activity involves the presence of various bodily fluids such as blood, semen, and/or saliva, as well as skin contact made between a perpetrator and a victim. Optimal recovery techniques for the collection of DNA evidence, following crime-relevant skin contact, can be dependent on the surface being sampled. Additional factors to consider include the body areas typically contacted during various activities and the likelihood of non-self-DNA being present in those areas prior to contacts of interest. Therefore, an understanding of DNA transfer, prevalence, persistence, and recovery on a body can aid in the interpretation of DNA results given activity-level questions and increase the value of the findings from this type of evidence. This review aims to summarise research on DNA-TPPR concerning various human body surfaces following different types of activities. This review examines the prevalence of background DNA on different skin surfaces, the reported DNA transfer associated with different forms of contact, and how different cofounding factors can affect the persistence of DNA. Full article

Background: Hospital autopsies, once considered fundamental to evidence-based medicine, have declined in many Western countries due to legislative changes, faith-based objections, and inadequate funding in public healthcare. However, the COVID-19 pandemic has revitalized interest in their importance for determining the cause of death and generating public health statistics. This study analyzes the factors contributing to this decline, with a focus on the Italian context and the new medicolegal perspectives arising in the post-pandemic era. Methods: The research was conducted through an analysis of 91 relevant scientific sources, including government documents, policy briefs, and academic studies. Legislative and regulatory factors influencing the reduction in hospital autopsies were examined, along with new technological and medicolegal perspectives that have emerged following the COVID-19 pandemic. Special attention was given to the Italian context and the pandemic’s impact on autopsy practices. Results: The analysis revealed that the perceived “low value” of autopsies often stems from technological advancements, which have led to the view of these procedures as redundant. However, in the post-COVID-19 era, there has been a renewed awareness of the medicolegal value of autopsies, with significant implications for public health statistics and the evolution of forensic medicine. Conclusions: The COVID-19 pandemic highlighted the vital role of autopsies in delivering accurate medical information, prompting renewed attention to these procedures in the post-pandemic era. Moving forward, hospital autopsies will need to balance technological innovations with traditional medicolegal practices, paving the way for new perspectives in forensic medicine and public health data management. Full article

Background: Nowadays, exotoxic substance intake is among the most frequently employed methods of suicide. Self-poisoning is quite common among psychiatric patients treated in hospitals. Psychotropic drugs used for suicide include phenothiazines. Promazine hydrochloride (Talofen©) is an alpha-lytic phenothiazine neuroleptic with a high affinity for histaminergic H1 receptors and a low affinity for dopaminergic D2, serotoninergic 5-HT, alpha1-adrenergic, and muscarinic receptors, which may explain its potent sedative effect. The most common adverse effects include extrapyramidal syndromes, weight gain, orthostatic hypotension, QTc prolongation, convulsions, delirium, and psychosis. Rare adverse events include the potential occurrence of autoimmune syndromes and vasculitis. Methods: We report herein the delayed death of a 59-year-old woman due to cardiocirculatory arrest on an arrhythmic basis in the context of vasculitis of the small pulmonary vessels and prolongation of the QTc interval secondary to voluntary acute intoxication with promazine hydrochloride. Results: The incident occurred in a psychiatric patient with a history of prior self-harming acts. Histological investigations revealed wavy fibers in the heart, a lymphocytic granulocyte infiltrate in the walls of small- and medium-caliber vessels, and spotty perivascular deposition of histiocyte-macrophage cells in the lungs. Immunophenotypic investigations showed the prevalence of CD15+ and T-CD3+ elements, thus identifying a small vessel vasculitis. These findings were consistent with the literature regarding adverse events following the intake of promazine hydrochloride, although vasculitis is rare. Conclusions: Thus, while QTc lengthening and arrhythmic incidents are widely reported events associated with promazine hydrochloride use, the development of a rare condition such as pulmonary vasculitis undoubtedly played a synergistic and decisive stressogenic role in the genesis of the cardiac event, leading to irreversible functional arrest. Full article

Background: SARS-CoV-2 is classified as a class 3 biological agent; therefore, autopsies on positive subjects must be performed in BSL 3 sectorial rooms. However, many centers lacking such facilities perform molecular nasopharyngeal swabs for SARS-CoV-2 on corpses before autopsy. This approach, though, is marked by prolonged reporting times and extremely high costs. This study aims to compare the results of molecular swabs (RT-PCR) with rapid antigen swabs (RAT) in order to assess if RAT can serve as the sole test for determining corpse positivity or negativity. Methods: Sixty corpses with positive molecular nasopharyngeal swabs for SARS-CoV-2, performed either ante-mortem or post-mortem, were selected. Afterward, they underwent rapid antigen swabs within 0 to 11 days after the last molecular exam. Results: Out of 60 corpses with positive molecular swabs, 52 antigen swabs were positive (86.67%), and 8 were negative (13.33%), indicating a sensitivity of 86.66% and specificity of 100%. Conclusions: Considering the sensitivity and specificity values observed in this study, RAT could be used as the primary investigation on corpses, especially in centers that lack BSL 3 sectorial rooms. Molecular swabs could then serve as a secondary test for subjects negative on RAT. Full article

Background/Objectives: Facial soft tissue thickness (FSTT) data are extensively utilized in forensic and medical sciences, serving as a foundational element for craniofacial reconstruction and identification methods. This study aims to analyze the differences in FSTT measurements between upright and supine positions in living subjects. Methods: The study sample consisted of 121 participants aged 20 to 86 years from Slovakia. Biological sex and age data were collected. FSTT measurements were taken at eight medial facial line landmarks and eight bilateral landmarks using a non-invasive General Electric LOGIQe R7 ultrasound device. Results: The results indicate that the head position significantly influenced more than half of the landmarks, with mean differences not exceeding 1.31 mm. Most FSTT values were higher in the horizontal position. Younger males and females exhibited significant differences in FSTT across various regions, including the eye, cheek, nose and mouth, with discrepancies in the forehead, chin, and cheek regions among younger males. In older males, only the gonion region showed a significant position-related difference, while older females demonstrated substantial FSTT changes at five landmarks, with the largest difference (1.31 mm) observed at the mandible, accounting for 15.74% of the mean FSTT. Compared to younger groups, older females exhibited higher FSTT values in the upright position. Conclusions: These findings suggest that measurements in an upright position may be more suitable for facial reconstruction, as positional changes in FSTT can occur in both positive and negative directions. Full article

Background/Objectives: The aim of this study was to examine the relationship between the mesiodistal and buccolingual alveolar diameters and the usual crown and cervical diameters and to test the reliability of these alveolar measurements for their application in dental anthropology in cases of missing teeth. Methods: A total of 127 skeletal individuals from the identified osteological collection of Certosa Cemetery (Bologna, Italy) were used in this study. After the evaluation of limiting factors, only the central incisor to the second premolar was analysed due to a null or small sample size for the molars. The mesiodistal and buccolingual diameters were measured at the level of the crown, cervix and alveolus. The relationship between the mesiodistal and buccolingual crown or cervical diameters and the alveolar measurements was assessed. Results: The buccolingual alveolar diameters showed consistently significant relationships with their equivalent cervical and crown diameters, while the mesiodistal alveolar diameters did not show consistent relationships. Furthermore, the patterns of phenotypic variation were similar for the alveolar, cervical and crown areas. Thus, the alveolar areas appear to show similar levels of variability compared with the equivalent crown and cervical areas. Conclusions: Alveolar measurements may serve as suitable proxies in comparative phenotypic variation studies and can be considered a useful supplement to the standard odontometric data collection strategy. The measurements proposed in this study for the evaluation of the alveoli are a valid alternative in situations in which teeth are not available for measurement, such as in forensic and archaeological contexts. Full article

Background/Objectives: The Scanning Electron Microscope (SEM), combined with an Energy Dispersive Spectrometer (EDS), has been, for over fifty years of practical experience and research in the field, the analytical system of choice for the investigation and analysis of Gun Shot Residues (GSRs). However, the interpretation of analytical results has profoundly changed in recent decades. Specifically, the criteria for evaluating particles presumptive of contamination of a possible discharge have evolved, assessments regarding possible primary/secondary transfer phenomena have been refined, and the retention times of particulate matter on various types of surfaces involved during the discharge have been revalued. The purpose of this study is to provide a formal representation that links together the firearm memory effect, namely the formation of composite characteristic GSRs resulting from the use of the same Firearm but with ammunition having different metallic alloy constituents and different primer mixtures, and the decay time. Methods: The deduced mathematical model is based on experimental results reported in the scientific literature listed below, and it has been elaborated with a series of non-contradictory assumptions, each of which plays a specific role in the mathematical formalism used. Results and Conclusions: This model, although not yet validated through rigorous experimentation, represents a valuable tool in investigations related to the firearm memory effect when forensic specialists have collected GSR samples from the hands of the alleged shooter within four hours of the shooting. Full article

Background/Objectives: Sex estimation constitutes an important tool in the process of identifying an anonymous individual in forensic contexts. The bones commonly used in sex estimation are those that exhibit greater sexual dimorphism, such as the pelvis or the femur. However, these bones are not always available, which means that it is necessary to find alternative bones for analysis. The main purposes of this study include the assessment of fibular and tibial sexual dimorphism in samples from three Portuguese reference skeletal collections, and the development of metric models for the estimation of biological sex. Methods: A sample of 290 individuals (160 females; 130 males), belonging to the Coimbra Identified Skeletal Collection (training sample), the Lisbon Identified Skeletal Collection (test sample), and 21st the Century Identified Skeletal Collection (training sample), was employed to develop models for sex prediction through logistic regression. Results: From the identification of the most dimorphic bone dimensions, 13 models were created with an accuracy ranging between 80.1% and 89.7% in the training sample (under cross-validation), and between 82.5% and 91.7% in the test sample Conclusions: The results of this work show that predictive models based on the fibula and tibia can be accurate and unbiased. Full article

Background: Strangulation by ligature, most frequently employed for homicidal purposes, is not a common suicide method. Even more infrequent is the use by the victim of cable ties as a tool of self-strangulation. Methods: We describe a case of a 50-year-old woman who was found dead with a cable tie tight around her neck. In our case, analysis of the circumstantial data and the psychopathological history of the victim—along with an external examination, an autopsy, and toxicological findings—was crucial in the differential diagnosis between death intentionally inflicted by a third person and suicide. Through a narrative review conducted by performing a literature search using online resources (PubMed, Google Scholar, and ScienceDirect). Results: we were only able to identify eight similar cases. Conclusions: These were compared with our case, to trace similarities and differences, useful in guiding the forensic doctor in the diagnosis of death in such circumstances. Full article

Background: The identification of victims in mass disasters is a challenging task, particularly when forensic teams must address fragmented human remains. Objectives: This article reports two necropsy cases from the 2019 collapse of the Brumadinho mine tailing dam, the largest humanitarian disaster in Brazilian history. Results: In both cases, identification was achieved through comparative anthropological analysis of complex tattoos. Positive identification was based on the presence of multiple coincident points between postmortem (PM) and antemortem (AM) photographic records of the tattoo designs, along with the absence of exclusionary elements. Conclusion: The authors propose that the comparative analysis of PM and AM tattoos should be more widely adopted as a low-cost, rapid identification method, particularly in complex forensic scenarios such as mass disasters and other challenging cases in the medical and forensic anthropology context. Full article

Background/Objectives: Rapid DNA instruments are gaining interest in the forensic community as a means of generating DNA profile information more quickly than standard laboratory workflows, and they have the potential to be carried out in decentralized structures of the main laboratory, such as in French overseas territories, where no laboratory facilities are installed. Although this system has been shown to be effective in analyzing rich traces (such as blood) sampled on a swab, it has the disadvantage of consuming the entire swab for analysis. Since it is impossible to double the sampling from very few blood stains, we designed a subsampling protocol of the main swab for analysis on RapidHIT ID^® instruments. Methods: Two volumes of blood (10 µL and 150 µL) from four individuals were applied to a regular Copan flocked swab and then subsampled by three different operators using a Copan mini (subungual) flocked swab to recover a portion of the biological material. Results:The analysis of the mini swabs allows us to obtain a complete genetic profile regardless of the initial volume, with a better genetic profile intensity associated with a higher initial volume deposited on the regular swab. Conclusions: Therefore, this study presents a novel, effective, and adaptable subsampling method that has the potential to significantly improve forensic DNA analysis, particularly in remote or decentralized settings. It offers a flexible solution to current limitations of RapidHIT ID^® technology and paves the way for future advancements in genetic forensic science. Full article