Forensic science international最新文献

Illicit drugs are often made in less-than-sterile environments and can be stored in ways which can be detrimental to any DNA present, such as whether they are exposed to UV radiation. Previously, analysis of how exposure to UV impacted DNA for forensic applications has been in controlled laboratory conditions isolating a single component of UV radiation and often on DNA-rich samples such as bloodstains or saliva. To evaluate DNA persistence in more realistic conditions, capsules, such as those used to distribute controlled substances, were manually made and then packed into ziplock bags. The persistence of DNA deposited on capsules was examined when left indoors in either, complete darkness, direct sunlight in high UV conditions (summer) or in low UV conditions (winter) for three weeks in ambient room temperature. The DNA yield, STR DNA profile quality and degradation index were all analysed to determine the impact of varied UV exposure on DNA in a semi-temperature-controlled environment. Capsule samples exposed to high UV conditions had significantly reduced DNA yields, a lower number of alleles from the capsule handler and, thus, reduced likelihood ratios compared to capsules exposed to darkness and low UV conditions. Samples exposed to either darkness or low UV had little-to-no differences in all DNA quality measures tested. Despite a decreased DNA yield and poorer quality DNA profiles, capsules left in high UV conditions for three weeks have sufficient DNA for DNA profiles with over half the genetic information present. The storage conditions of drug capsules, either before or after seizure by law enforcement, can impact the DNA persistence in as little as three weeks, which is problematic for often already low concentrations of DNA in trace samples.

Some bullets, called tracer and API bullets, contain a pyrotechnical charge. The charge in the bottom of a tracer bullet burns in flight and enables the shooter or an observer to see the bullet's trajectory. An Armor Piercing Incendiary (API) bullet contains a hard core and a pyrotechnical charge that ignites on impact with a hard target. These bullets are designed to both pierce armor and ignite combustible materials. Both tracer and API bullets are quintessentially military ammunition, but some 7.62x39mm caliber variants are occasionally used in crimes. This fact triggered a study on the behavior of these bullets in soft tissue. Two different types of tracer bullets and two different types of API bullets were tested. The tracer bullets behaved similarly in a soft tissue simulant, in terms of energy transfer and deflection. These bullets deflected more from their original trajectory than the tested API bullets and the full metal jacket (FMJ) bullets that were tested as a reference. The two types of API bullets behaved completely different in the soft tissue simulant, especially in terms of energy transfer. One type yawed very late in the simulant and stayed intact, transferring little kinetic energy. The other type yawed early and disintegrated in the simulant, transferring much more of its kinetic energy, causing massive tissue (simulant) disruption. The difference in bullet behaviour was caused by a small but important difference in bullet design with the two types of API bullets.

Skeletal remains are the only source of the genetic material of decomposed organisms or once-lived species. Unlike, soft tissues they are highly mineralized, and their anatomical and morphological structure prevents their deformation in the presence of adverse environmental factors. Therefore, bones and teeth protect the Deoxyribonucleic Acid (DNA) inside them. Obtaining DNA from hard tissues comes with challenges like contamination, degradation, PCR inhibitors, damage done by the environment on remains, etc. Traditional methods have been in use for a long time. To overcome the challenges in extracting DNA from hard tissues, researchers introduced various modifications, with time, to the standard procedures. We have reviewed the innovative approaches developed during the period ranging from 2000 to 2024, using the Google Scholar search engine. The last innovative method was discovered in 2021. Each method solves a particular challenge and makes it easier for future researchers to opt for a suitable protocol according to the specific requirements of their study. The methods were renamed based on their core specification, such as Carrier-Mediated Precipitation Method, CTAB Method, Buffered-Nondestructive Extraction Method, MDNAMI Method, Demineralization protocol, Rapid Column-based DNA Extraction, Bone Powdering and Bone Slicing, Short Fragmented DNA Extraction, Highly Degraded DNA Extraction, and Non-destructive Tooth DNA Extraction. A collaboration of researchers from forensic science, anthropology, archeology, evolutionary biology, molecular biology, etc. may develop more sophisticated techniques that ease extraction, increase yield, and reduce contamination of DNA from hard tissues.

During any crime scene investigation, forensic experts gather a variety of evidence in various forms, often degraded, contaminated, or fragmentary in nature. Arson-associated suicide or homicidal cases often result in partial or complete burning of this evidence, making the acquisition of crucial information more challenging. Proteins found in biological samples serve as crucial sources of evidence in criminal investigations due to their abundance within the body and greater stability than another biological macromolecule. Protein based technologies are gaining momentum for investigating wide range of forensic cases. In the present study, we probed different modifications in chicken protein subjecting after burning with petrol and kerosene individually. Structural changes and modifications in burnt chicken meat protein samples were analyzed by various biophysical techniques, such as absorption and fluorescence spectroscopy. Gel-based method such as electrophoresis was performed which showed different degradation patterns under the influence of petrol and kerosene. Our results showed that petrol-exposed meat sample caused higher rate of protein degradation than kerosene exposed samples, over a period of 12 days. Prevalent oxidative modifications, including increased carbonylation and decreased thiol levels were observed in both petrol and kerosene treated sample attributing oxidative stress environment caused by burning. Present study highlights that petrol is more potent in causing damage and protein modification than kerosene. Furthermore, this study elucidates the application of protein-based methods in forensic science, which can serve as a corroborative approach in ascertaining the cause of death in cases of burning, particularly where fuel has been utilized.

The identification of deceased with unknown identity is a key task in forensic investigations. Current radiologic identification approaches are often elaborative, lack statistical evidence, and are dependent on the examiner's experience and expertise. Thus, the aim of this work was to develop a 3D computational and thus, more objective identification approach. An anonymised antemortem (AM) dataset consisting of 90 computed tomography (CT) scans containing the sternal bone and the fifth thoracic (T5) vertebra, as well as an anonymised postmortem (PM) dataset consisting of 40 CT scans containing the sternal bone and the T5 vertebra were included in this work. The PM data had corresponding AM data within the AM dataset. A custom-made python script was established to automatically perform 3D segmentation of the sternal bones and the T5 vertebrae, respectively, and to register the AM data to the PM data. The similarity between the registered AM data and the PM data was assessed via the Dice coefficient. The highest Dice score was intended to indicate a match. An accuracy of 86.7 % was achieved for the sternal bone, and 88.9 % for the T5 vertebra, respectively. In some cases, insufficient CT quality and altered bone morphology due to surgical interventions hindered correct matching. However, by combining the sternal bone and T5 vertebra for identification, the accuracy was increased to 97.8 %. Hence, the presented tool seems to be a promising 3D computational approach for objective identification of unknown deceased, which could be further adapted for other bone structures. The final tool is publicly available.

The succession, development, and behavior of necrophagous insects on decomposing remains are used by forensic entomologists to estimate the minimum post-mortem interval (minPMI). Carcasses are often recovered from concealed environments, such as burials, wrapping, suitcases and waste bins, where they are protected from abiotic and biotic factors, including carrion fauna. The present study represents the first comprehensive research on concealed environments in Australia. Stillborn piglets (Sus scrofa domesticus L.) placed in hard-covered suitcases (N = 40, restricted access) and wheeled bins (N = 20, partially restricted access) were compared with controls (N = 5, exposed) placed on the soil surface, over a period of 164 days (Austral winter to spring). The analysis compared the decomposition process patterns and considered the insect assemblages colonizing the carcasses in each concealment type and the controls. Results show that 1) insects were attracted to the control carcasses within hours of placement in the field (Day 1, D1), followed by wheeled bin carcasses (D3) and suitcase carcasses (D4); 2) carcasses reached skeletonization on D65 (exposed), D108 (wheeled bin) and D136 (suitcase); 3) the assemblages of necrophagous insect species were different between the exposed and the concealed carcasses; 4) blowflies (Diptera: Calliphoridae) were the most prevalent insects colonizing the controls and wheeled bins, while coffin flies (Diptera: Phoridae) were the most prevalent in the suitcases, with some colonized by black soldier flies (Diptera: Stratyiomiidae). The results of this research contribute to the understanding of decomposition processes and insect activity in restricted access environments and help provide a more accurate estimation of the minPMI in forensic cases.

In 2018, after law enforcement announced it had used a technique called forensic investigative genetic genealogy (FIGG) to identify the Golden State Killer, we conducted a U.S. general population survey and found most respondents supported using FIGG to solve violent crimes. Since then, FIGG has helped close hundreds of criminal cases, but it also has weathered controversies. On FIGG's fifth anniversary, we conducted an expanded, follow-up survey with U.S.-based participants to determine if public opinion had changed and found continued support for FIGG across most applications. The same proportion (91 %) of respondents in the 2018 and 2023 surveys endorsed using FIGG in genetic genealogy databases to help identify perpetrators of violent crimes. Similar to the 2018 survey, only 57 % of respondents supported FIGG to help identify perpetrators of non-violent crimes. The results indicate that U.S. policies that have been adopted for FIGG are generally consistent with the opinions of our survey respondents over time. Nonetheless, there are opportunities to strengthen FIGG governance with the goal of maintaining public trust in the technique.

Individual identification of unknown deceased is a vital function carried out by medical professionals, thus many tools have been developed or tested towards its end. One of the tools tested and still being tested is post-mortem computed tomography [PMCT]. This review aims to summarise the current state of using PMCT for personal identification beyond odontology. We found that most medicolegal researchers had a positive view of using PMCT for individual identification or for disaster victim identification. They have shown PMCT scans can be compared with a wide range of AM material - ante-mortem computed tomography [AMCT] scans, AM radiographs, or even textual AM medical history - for a successful identification. The use of textual medical history suggests the potential to create an artificial intelligence model that could quickly highlight areas of comparison. Anatomical body structures, pathological changes, or foreign bodies provide bases of comparison when using PMCT for individual identification. We found most (79 %) researchers have used qualitative methods to compare PMCT with AM material. Likewise, researchers so far have focussed on the axial skeleton (sans pelvis) when testing the viability of comparing specific body structures between AM material and PMCT scans. More body structures remain to be tested for their viability in personal identification, especially using quantitative methods.

Diagnosing drowning as a cause of death remains complex in forensic pathology, demanding integration of autopsy findings, contextual evidence, and case-specific variables. This study systematically reviews literature on lung weights in adult drowning cases, analyzing data from 20 studies to evaluate lung weight as an evidentiary factor in the diagnosis of drowning deaths. Additionally, this study seeks to examine the impact of covariates such as water salinity (freshwater vs. saltwater) and sex differences on lung weight in drownings deaths. Our meta-analysis examines the weighted average mean and median lung weights, comparing 3010 drowning cases with 1494 controls. We observed significantly higher lung weights in drowning cases compared to controls, with an observed mean difference of 243 g (95 % CI: 217 - 263 g, p < 0.001). Differences in lung weight across cases indicate that factors such as water salinity and sex are associated with the weight of the lungs. However, guidelines for how to interpret lung weight in the medico-legal assessment of cause of death in a specific case is still elusive, since the variation in lung weight is relatively large. Recommendations for future research is to include a standardized reporting of lung weight in categories of age, body size and sex, and to include appropriate control groups to improve the accuracy of drowning diagnosis.

The search for missing people is a complex and intensive undertaking. Predictive models (such as RAG mapping and geographic profiling) in combination with drone-mounted technologies can improve these searches by driving down time and monetary costs, gathering new types of data and reducing the need for investigators to expose themselves to dangerous environments. Promising technologies to discover traces of clandestine burials in the landscape are LiDAR, RGB photography, multispectral and hyperspectral imaging, as well as infrared/thermal photography. This review covers the existing literature on these techniques and discusses future opportunities and directions.