Search

Objective: Aim: To explore the capabilities of the modern 3D modeling method for various elements of gunshot wounds caused by 9 mm caliber bullets, intending to integrate these findings into the theory and practice of forensic medicine., Patients and Methods: Materials and Methods: The research began with a series of experimental shots, during which the morphological features were examined through their 3D spatial reconstruction. The entire series of experimental shots was conducted using an automatic pistol IZH 70-01 equipped with 9.0 mm caliber bullets. The ballistic clay Roma Plastilina No.1, manufactured in the USA, was utilized as a material for conducting standard ballistic tests according to the standards of the NIJ (National Institute of Justice) and HOSDB (Home Office Scientific Development Branch)., Results: Results: The research was continued during the performance of forensic examinations involving actual cases of gunshot injuries. The dimensions of individual elements of the wound channel were measured in both experimental and expert cases using conventional measuring tools, as well as after their 3D modeling, utilizing graphic editors such as "Agisoft Photoscan" and "3ds max"., Conclusion: Conclusions: In the course of creating and studying experimental and expert 3D models, the dimensions of individual morphological elements of the wound channel were recorded with an accuracy that exceeded the results obtained through measurements using traditional measurement methods by ten times.

The full combustibility and strong discontinuity characteristics of module charge result in significant differences from conventional mode, making it challenging for traditional two-fluid methods to effectively reveal its particle dispersion mechanism. In this study, the particle element method for module charge were developed and applied for modeling the interior ballistics to overcome above drawback. Firstly, based on the characteristics of module charge and particle aggregation, criteria for dividing particle elements and methods for motion calculation are proposed. Next, particle element solver and CFD solver are constructed and mutually coupled for solution. Finally, validation is conducted under the condition of three modules charging. The computational results show that the particle element method can effectively predict the pressure and velocity inside the chamber, consistent with experimental results, the pressure error is 5.55 % and the velocity error is 0.79 %. The particle element method reproduces the combustion process with variable particle mass, accurately presenting the distribution of the flow field and temperature. Moreover, it fundamentally explains that pressure fluctuations occur due to the presence of free space and changes in the flow field caused by the movement of the propellant bed. The particle element method can provide scientific research methods and technical support for the development of module charge technology.

The large compositional space of high entropy alloys (HEA) often presents significant challenges in comprehensively deducing the critical influence of atomic composition on their mechanical responses. We propose an efficient nonparametric kernel-based probabilistic computational mapping to obtain the optimal composition of HEAs under ballistic conditions by exploiting the emerging capabilities of machine learning (ML) coupled with molecular-level simulations. Compared to conventional ML models, the present Gaussian approach is a Bayesian paradigm that can have several advantages, including small training datasets concerning computationally intensive simulations and the ability to provide uncertainty measurements of molecular dynamics simulations therein. The data-driven analysis reveals that a lower concentration of Ni with a higher concentration of Al leads to higher dissipation of kinetic energy and lower residual velocity, but with higher penetration depth of the projectile. To deal with such conflicting computationally intensive functional objectives, the ML-based simulation framework is further extended in conjunction with multi-objective genetic algorithm for identifying the critical elemental compositions to enhance kinetic energy dissipation with minimal penetration depth and residual velocity of the projectile simultaneously. The computational framework proposed here is generic in nature, and it can be extended to other HEAs with a range of non-aligned multi-physical property demands. [ABSTRACT FROM AUTHOR]

Machine learning (ML) is well suited for the prediction of high-complexity, high-dimensional problems such as those encountered in terminal ballistics. We evaluate the performance of four popular ML-based regression models, extreme gradient boosting (XGBoost), artificial neural network (ANN), support vector regression (SVR), and Gaussian process regression (GP), on two common terminal ballistics’ problems: (a) predicting the V50 ballistic limit of monolithic metallic armour impacted by small and medium calibre projectiles and fragments, and (b) predicting the depth to which a projectile will penetrate a target of semi-infinite thickness. To achieve this we utilise two datasets, each consisting of approximately 1000 samples, collated from public release sources. We demonstrate that all four model types provide similarly excellent agreement when interpolating within the training data and diverge when extrapolating outside this range. Although extrapolation is not advisable for ML-based regression models, for applications such as lethality/survivability analysis, such capability is required. To circumvent this, we implement expert knowledge and physics-based models via enforced monotonicity, as a Gaussian prior mean, and through a modified loss function. The physics-informed models demonstrate improved performance over both classical physics-based models and the basic ML regression models, providing an ability to accurately fit experimental data when it is available and then revert to the physics-based model when not. The resulting models demonstrate high levels of predictive accuracy over a very wide range of projectile types, target materials and thicknesses, and impact conditions significantly more diverse than that achievable from any existing analytical approach. Compared with numerical analysis tools such as finite element solvers the ML models run orders of magnitude faster. We provide some general guidelines throughout for the development, application, and reporting of ML models in terminal ballistics problems.

Stromboli is a volcanic island in a persistent state of activity, located off the northern coast of Sicily. The paroxysms have been the most powerful explosive phenomena at Stromboli in the last 150 years. These explosions can produce ballistic projectiles that can heavily affect trails and observation sites as well as hit inhabited areas at lower elevations, down to the coast. On July 3, 2019, a paroxysm significantly affected a great portion of the island with ballistic projectiles. In particular, many decimeter and meter-sized spatter bombs hit the W flank of Stromboli, and ignited multiple fires. In May 2022, we conducted an Unmanned Aerial System photogrammetric campaign over a sector of the W flank of Stromboli that was heavily affected by the paroxysm. The largest clasts were still preserved after 3 years, not disturbed by significant mass wasting phenomena or human interference, and they were not yet hidden by the post-fire regrowth of the brush vegetation. In this study, we constrained the main sources of uncertainty affecting the bombs distribution on the ground, by characterizing a percentage of uncertain clasts, testing various density estimators, and by modeling an areal buffer around the mapped clasts. We produced a 0.18 km2 wide 1.6-cm resolution orthomosaic, a 10-cm resolution Digital Surface Model, and 2813 outlines of the mapped ballistics. Spatial distribution of the ground cover and associated uncertainty were analyzed as a function of the distance and of the angular direction from the source. [ABSTRACT FROM AUTHOR]

Abstract The large compositional space of high entropy alloys (HEA) often presents significant challenges in comprehensively deducing the critical influence of atomic composition on their mechanical responses. We propose an efficient nonparametric kernel-based probabilistic computational mapping to obtain the optimal composition of HEAs under ballistic conditions by exploiting the emerging capabilities of machine learning (ML) coupled with molecular-level simulations. Compared to conventional ML models, the present Gaussian approach is a Bayesian paradigm that can have several advantages, including small training datasets concerning computationally intensive simulations and the ability to provide uncertainty measurements of molecular dynamics simulations therein. The data-driven analysis reveals that a lower concentration of Ni with a higher concentration of Al leads to higher dissipation of kinetic energy and lower residual velocity, but with higher penetration depth of the projectile. To deal with such conflicting computationally intensive functional objectives, the ML-based simulation framework is further extended in conjunction with multi-objective genetic algorithm for identifying the critical elemental compositions to enhance kinetic energy dissipation with minimal penetration depth and residual velocity of the projectile simultaneously. The computational framework proposed here is generic in nature, and it can be extended to other HEAs with a range of non-aligned multi-physical property demands.

Study of the engraving process is significant for interior ballistics. Due to the high transient and strong nonlinear characteristics of the engraving, research on the engraving mechanism is challenging. In this paper, based on the one-dimensional two-phase flow model of interior ballistics coupled with explicit dynamics software, finite element simulation of the engraving is carried out to obtain the changes of parameters during the engraving process, and the dynamic characteristics of the projectile engraving are discussed. By comparing the simulation results with the experimental data, the accuracy of the coupling method in this paper is verified. The relationship between the structural parameters of the sealing band and the extrusion resistance is revealed, and the influence of the extrusion resistance on the dynamic characteristics of the projectile is demonstrated. The simulation results can provide an essential reference for selecting a reasonable sealing band structure. [ABSTRACT FROM AUTHOR]

Introduction. In accordance with the Polish law, pneumatic weapons are weapons that use compressed gas to set a bullet in motion and generate a discharge energy of more than 17J. In recent years, Poland has seen an increase in crimes committed with pneumatic weapons. The research aim of the present study was to measure the velocity of selected 5.5 mm and 6.35 mm caliber shot and to create a model of a human thigh using a pig femur. Material and methods. This study used Air Arms Hi-Power Xtra FAC cal. 5.5 mm and FX Bobcat Mk II cal. 6.35 mm carbines and Haendler& Natterman’s Spitzkugel, Hollow Point and Baracuda cal. 5.5 mm and 6.35 mm lead shot and Excite Apollo cal. 5.5 mm and Black Max Lead-Free cal. 6.35 mm lead-free shot. The velocity of the shot at a distance of 10 m was measured and its kinetic energy was calculated; pig femurs were measured and CT imaging was performed. Results. The 5.5mm caliber shot reached velocities between 253 m/s and 278 m/s, obtaining energies between 27J and 44J. The 6.35 mm cal. shot reached velocities between 242 m/s and 254 m/s and energies between 52J and 59J. Pig femurs had an average weight of 410 g, a length of 239 mm, and a shaft diameter at mid-length of 30.6mm. The thickness of pig femur shaft walls was variable. A ballistic model of the human thigh was created using gelatin available in Poland. Conclusions: 1. The number of registered crimes with pneumatic weapons and the wide access to pneumatic devices with the possibility of design modifications justify the initiation of experimental studies on the assessment of gunshot injuries from pneumatic weapons. 2. The parameters of the shaft of a pig femur obtained from pigs weighing about 115 kg are similar to those of a human adult femur, which makes it possible to create a human thigh model. 3. Of the 5.5 mm cal. shot, the highest impact energies were generated by barracuda type shot, and of the 6.35 mm cal. shot, it was barracuda type and lead-free shot. 4. The thickness of the bony layer of the pig femur shaft is heterogeneous; the posterior wall of the shaft is the thickest, the lateral wall is the thinnest; however, it shows the greatest individual variability.

The use of ordnance gelatine has been widespread in the field of ballistics as a simulant for soft tissue when assessing ballistic threats. However, the traditional method of preparing ordnance gelatine is time-consuming and requires precision to ensure that the final mold meets the required specifications. Furthermore, temperature control is necessary post-production, and there are limitations on its usage duration. To address these issues, manufacturers have developed pre-mixed, gelatine-like products that are stable at room temperature and require less preparation time. Nonetheless, it is uncertain whether these new products can perform in the same manner as the gold standard of ordnance gelatine. This study used five types of blocks, including ordnance gelatine (10% and 20%), Clear Ballistics (10% and 20%) and Perma-Gel (10%) and subjected them to 9 mm, 0.380 Auto fired from a universal receiver and a 5.56 × 45 mm ammunition fired by a certified firearms instructor. Delta-V and total energy dissipation were measured after each test using data collected from ballistic chronographs placed in front of and behind each block. High-speed video was recorded, and a cut-down analysis conducted. The findings revealed variations in energy dissipation and fissure formation within the block, with greater energy based on fissure formation observed in the ordnance gelatine. Additionally, the high-speed video showed the occurrence of secondary combustions occurring in the premixed gelatines., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

The study examines the results of numerical simulations of the penetration of a 7,62mm x 63, AP, M2 projectile through a target. Model validation involved a numerical simulation of 7,62mm x 63, AP, M2 projectile penetration through an AA5083H116 target, for which experimental results were available in the literature. The results of the numerical simulation were used for regression analysis - to calibrate the Recht-Ipson model for the given projectile. Furthermore, penetration analyses of 7,62mm x 63, AP, M2 projectiles through various target materials were performed at consistent projectile velocities and mesh sizes. As expected, bainitic steels exhibited the highest resilience, demonstrating that increased material hardness and tensile strength correlate with enhanced projectile penetration resistance.

The use of less lethal weapons aims to mitigate civilian casualties caused by firearm use. However, due to numerous cases in which these weapons caused serious injuries, even lethal injuries, both legislation and the forensic field are interested in characterizing and regulating them better. In the forensic field, there is a lack of strong research about injury patterns of these weapons which makes it difficult to identify the type of weapon employed. In this study, the main objective was to characterize the injury pattern produced by the impact of the 9 mm P.A.K. projectile. A porcine model was used. Four different distances were studied: firm contact, 10 cm, 60 cm and 110 cm, using 3 of the more representative anatomical sites: the head, the hind leg and the ribs. The average measurement of the entrance orifice varied according to the anatomical site, being 6.67 mm wide and 6.25 mm long in the thorax, 7.3 mm wide and 8.8 mm long in the hind legs, and 7.62 mm wide and 7.54 mm long in the head. The variation in width and length measurements was not found to be directly related to the shot distance. The gunshot residues had similar characteristics to those of conventional lead projectiles, however there was more unburned powder deposit near the wounds, with a less dense soot and more dense powder tattoo. Depth varied widely regardless of tissue and firing distance, although loss of penetrating power and injury is observed as one moves away from the target., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Abstract: The present study investigated the main morphological differences between the permanent cavities formed by 4 different types of projectiles fired from .38 SPL caliber cartridges in blocks of 10% ballistic gelatin with standardized formulation (Federal Bureau of Investigation Protocol), all fired from the same distance and from the same firearm, associated with its performances in external and terminal ballistics. The velocity or the mass presented by a firearm projectile will not always be solely responsible for the final configuration of the permanent cavity, in which the projectile design, for example, is an equally important element. Each type of projectile tested in the present work generated a different kind of permanent cavity, but they also varied in velocity (m/s) and energy (J). The use of 10% ballistic gelatin in scientific research that seeks to investigate the external and terminal ballistics of projectiles can contribute to the practice of professionals working either in forensic pathology or applied ballistics scenarios, as they can experimentally simulate the events that can occur in the tissues of victims inflicted by gunshot wounds, which also allows important applications in the medical, commercial, civil, and military sectors that deal with products and technologies related to the human body., Competing Interests: The authors report no conflict of interest., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

When dealing with badly preserved cadavers or skeletal human remains, the assessment of death circumstances remains challenging. When forensic evidence cannot be taken from the skin and soft tissue, the information may only be deduced from more resistant elements such as bone. Compared to cranial gunshot injuries, reliable data on ballistic long bone trauma remains scarce. This study aims to define ballistic fracture characteristics in human long bones. The shaft of 16 femurs and 13 humeri from body donors was perpendicularly shot with a 9-mm Luger full metal jacket bullet at an impact velocity of 360 m/s from a distance of 2 m. Some bones were embedded in Clear Ballistics Gel®, and some were shot without soft tissue simulant in order to better visualise the fracture propagation on the high-speed camera. The fractures were examined macroscopically and compared between the sample groups. We consistently found comminuted fractures with a stellate pattern. Fracture details were classified into entrance, exit and general characteristics. For some traits, we detected different occurrence values in the group comparison. The results indicate that some of the traits depend on bone properties such as shaft diameter, bone length and cortical thickness. The presence of ballistic gel also influenced some fracture traits, emphasising the relevance of soft tissue simulant in osseous gunshot experiments. This study revealed new insights in the detailed fracture pattern of human long bones. These may serve as guidelines for the identification and reconstruction of gunshot trauma in human long bones., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Most firearm related homicides involve the deceased being forensically examined within a day or two, however, there are times when bodies have been examined and the fired components removed several days or weeks after death, when the body is in an active or advanced state of decomposition. In these cases, ballistic investigation has been found to be complicated due to the damage to the bullets, however the extent of this is not yet known. To date, there have been no studies investigating the effect of human decomposition and the subsequent analysis of bullets lodged in the body in an Australian context. Herein, seven fired copper jacketed bullets were manually inserted into three specific tissue types; lungs, abdomen and leg muscle (twenty-one bullets in total), of human donors in both cool and warm conditions at the Australian Facility for Taphonomic Experimental Research (AFTER). Bullets were removed every three days for a period of twenty-one days, and each bullet underwent manual microscopic examinations by firearms examiners across Australia. Results have indicated that the bullets corrode quickly in warm conditions, compared to bullets exposed to decomposition in cooler conditions. The results of this study will inform investigators and pathologists of the need to remove and examine fired bullets from decomposed bodies as soon as possible, especially in warm conditions to provide firearms examiners with the best opportunity to link fired bullets to a common source., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Three-dimensional (3D) imaging, primarily computed tomography (CT), has proven valuable in the documentation and analysis of gunshot injuries. Explicit visualization of findings may play a pivotal role in judicial settings. This forensic ballistics case study aimed to examine the potential of CT-based 3D reconstruction to digitally visualize gunshot cavities in ballistic gelatine. Three .30 caliber bullets of different types (full metal jacket, soft point, and expanding monolithic) were fired into standardized blocks of 10% ballistic gelatine. The blocks underwent CT scanning with clinical equipment. Gelatine and air were segmented from the CT data using an open-source software. 3D reconstruction views of the segmented gelatine and air components were created. The gunshot cavities were clearly observed in both gelatine and air segmentation. The differences in cavitation between bullet types were evident in both reconstruction approaches, although gelatine segmentation produced higher resolution of small details. The obvious benefit of digital reconstruction was the ability to freely tilt and rotate the 3D images, with the possibility of taking measurements manually or automatically from any plane. Moreover, all the data can be stored for future analysis. This study introduces a preliminary method for digital visualization and documentation of gunshot cavitation in ballistic gelatine, to be fine-tuned and implemented for research purposes and routine practice in forensic institutions., Competing Interests: Declaration of competing interest None., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Skeletal evidence usually constitutes the only source of information to interpret lesion patterns that help to clarify the circumstances surrounding death. The examination and interpretation of bone trauma are essential to the application and utility of anthropology as a forensic science. When discussing the effect of gunshot wounds in bone, it becomes imperative to differentiate between short and long-distance injuries based on clear, distinct, and observable signs. To contribute to the debate, our focus is directed toward the external analysis of the so-called circumferential delamination defect (CDD) as an observable proxy for close-range shooting (≤30 cm) and contact gunshot wounds in the skull. In the context of known extrajudicial killings, in which the perpetrators used short 9 × 19 FMJ ammunition in a close-range shooting, instances of CDD have been documented. Empirical evidence reinforcing the causal relationship between CDD and close-range shootings is presented. Elements' characteristics of firearm residues were also found in remains buried for up to 30 years. Primarily, this work shows that the concentrations of gunshot residues (Pb, Ba, and Sb) resemble those observed in fresh corpses with the same gunshot wound (GSW). Moreover, the correlation observed between CDD and gunshot residues, where the likelihood of CDD increases the closer to the head and the more perpendicular the shot angle is, reinforces CDD as a pivotal discriminatory factor in the skeletal evidence of short-range or contact shot. This research contributes to the field of forensic anthropology by providing fundamental insights into the etiology of CDD and its practical application., (© 2024 American Academy of Forensic Sciences.)

Contact shots to the head often leave behind biological traces inside firearm barrels, a phenomenon of great forensic interest. Until now, the visualization and preservation of these traces presented a significant challenge, lacking a reliable method. This study addresses this gap by searching for a suitable method to extract the traces within a casting. Using alginate or gelatine as suitable materials, the results were hampered by serious adhesion issues and their extraction out of the firearm barrel was impeded. Finally, the combination of 11% gelatine with 1% alginate, introduced into the barrel around a 'central spine', succeeded to consistently produce replicable castings. Experimental contact shots displayed a distinct staining gradient from the muzzle to the rear of the barrel, as revealed through endoscopy and proved in the macroscopic casting. The technique proved effective for various common handgun barrels and successfully preserved blood and gunshot residue (GSR) patterns within the barrel. This method offers the dual benefits of visually mapping staining patterns and securing localized samples for targeted molecular genetic analysis in forensic investigations., (© 2024. The Author(s).)

Gunshot wound analysis is an important part of medicolegal practice, in both autopsies and examinations of living persons. Well-established and studied simulants exist that exhibit both physical and biomechanical properties of soft-tissues and bones. Current research literature on ballistic wounds focuses on the biomechanical properties of skin simulants. In our extensive experimental study, we tested numerous synthetic and natural materials, regarding their macromorphological bullet impact characteristics, and compared these data with those from real bullet injuries gathered from medicolegal practice. Over thirty varieties of potential skin simulants were shot perpendicularly, and at 45°, at a distance of 10 m and 0.3 m, using full metal jacket (FMJ) projectiles (9 × 19 mm Luger). Simulants included ballistic gelatine at various concentrations, dental silicones with several degrees of hardness, alginates, latex, chamois leather, suture trainers for medical training purposes and various material compound models. In addition to complying to the general requirements for a synthetic simulant, results obtained from dental silicones shore hardness 70 (backed with 20 % by mass gelatine), were especially highly comparable to gunshot entry wounds in skin from real cases. Based on these results, particularly focusing on the macroscopically detectable criteria, we can strongly recommend dental silicone shore hardness 70 as a skin simulant for wound ballistics examinations., (© 2024. The Author(s).)