The effect of human decomposition on bullet examination.

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.

Characterization of wound infections among patients injured during the Ruso-Ukrainian war in a Role 4 hospital.

INTRODUCTION: The management of infections in war wounds is a problem aggravated by the presence of multiresistant bacteria and requires a combined approach with surgery. Literature has identified the risks and patterns of antibiotic resistance in previous armed conflicts, but the Russian-Ukrainian conflict has required the study of specific bacterial resistance patterns. METHODS: We included war-injured patients from the Russian-Ukrainian conflict transferred for treatment to the General Defense Hospital of Zaragoza from May 2022 to October 2023. Epidemiological data, factors related to the injury, presence of infection and microbiological results were collected; These data were subsequently analyzed statistically. RESULTS: Fifty-three patients were included in the study, with a mean age of 35.6 years; 83% were injured by an explosive mechanism and all received antibiotic therapy prior to transfer. Seventeen patients had skin, soft tissue or joint infection. Correlation was demonstrated with the presence of bone lesion (p 0.03), skin coverage defect (p 0.000) and presence of foreign bodies (p 0.006). Nine patients had monomicrobial cultures, and the most frequently isolated microorganisms were Gram negative bacilli (GNB) and Staphylococcus aureus. Virtually all GNB presented some resistance mechanism. CONCLUSION: Our work shows the correlation of war wound infection with the presence of foreign bodies and affected tissues. Likewise, the presence of polymicrobial wounds is emphasized, with a predominance of GNB and multidrug-resistant S. aureus.

Rare case of multiple self-inflicted gunshot wounds to the chest in Poland.

Multiple gunshot suicides are relatively rare and present significant challenges for investigators and forensic pathologists. In such cases, assessing the possibility of more than one shot being fired can be crucial in distinguishing homicide from suicide. We present a rare case of multiple self-inflicted gunshot wounds to the chest with severe injury to the heart and left lung. Both the sudden, unexpected death of the man, the unknown source of the firearm, and the number and nature of the injuries sustained seemed quite unusual. The investigation revealed that the wounds were self-inflicted at close range, and the interval between successive shots (estimated by witnesses at up to 2 min) suggests that even multiple gunshot wounds perforating the heart and lungs may not necessarily cause immediate incapacitation. Forensic investigations in such cases should be multi-faceted and include full autopsy and ballistics expertise, as well as witness testimony and medical history.

The deceleration of full metal jacket bullets in compact target models - A new approach.

The wounding potential of a projectile depends on its kinetic energy. The aim of the study was to investigate the deceleration of non-deforming full metal jacket handgun bullets (FMJ) in gelatine blocks of increasing length. The temporary cavity (TC) was visualized using a SA-X2 Photron camera. 126 test shots in 9 mm nominal calibre were fired under strict temperature control conditions (4°C) at small gelatine blocks ranging from 2 to 12 cm in length. The deposited energy was calculated based on the loss of bullet velocity through high-speed video analysis. The length of the TC was measured, when the TC reached its maximum height. The volume of the TC was approximated by a cylinder. Regression analysis showed a linear correlation between the length of the bullet path and the energy transfer. The constant deceleration of the FMJ bullets in gelatine up to 12 cm bullet path was confirmed across various brands and velocity ranges (270-450 m/s). Higher impact velocities correlated with increased loss of energy in the target medium. The shape of the bullet tip influenced the characteristic of deceleration. The volume of the tubular temporary cavity, derived from high-speed video records, was found to be proportional to the energy transferred. The proposed approach might be a valuable tool in advancing wound ballistics research.

A comparison of gelatine surrogates for wound track assessment.

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.

Skin simulants for wound ballistic investigation - an experimental study.

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.

Suicide by a construction nail fired from a pistol.

Penetrating head injury to accomplish suicide by a non-ammunition-related projectile discharged from a nail-gun is a very rare entity. The authors describe even much rarer, and the first reported case of a suicide penetrating head injury by a construction nail discharged from a blank cartridge of a pistol. The absence of beveling and muzzle impression, the non-ejection of the discharged cartridge, and the exit of just the tip of the nail from the other side of wound were the atypical features in this firearm fatality sustained at a contact-range. The entry wound prototypes like abrasion and grease collar, and blackening were absent. An improvisation to insert a construction nail into the chamber of firearm, for utilization as a projectile was another unique highlight here. The deceased was a construction builder. Being debt-ridden, he probably could not manage to purchase even one live cartridge for his licensee pistol to bring suicidal ideation to culmination.

New alginate-gelatine method for casting of staining inside firearm barrels.

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.

Observing the fragmentation of two expanding bullet types and a full metal-jacketed bullet with computed tomography-a forensic ballistics case study.

Computed tomography (CT) may have a crucial role in the forensic documentation and analysis of firearm injuries. The aim of this forensic ballistics case study was to explore whether two types of expanding bullets and a full metal-jacketed bullet could be differentiated by inspecting bullet fragments and fragmentation pattern in CT. Three types of .30 caliber bullets (full metal-jacketed Norma Jaktmatch, expanding full-copper Norma Ecostrike, and expanding soft-point Norma Oryx) were test fired from a distance of 5 m to blocks of 10% ballistic gelatine. CT scans of the blocks were obtained with clinical equipment and metal artifact reduction. Radiopaque fragments were identified and fragmentation parameters were obtained from the scans (total number of fragments, maximum diameter of the largest fragment, distance between entrance and the closest fragment, length of the fragment cloud, and maximum diameters of the fragment cloud). The fragmentation patterns were additionally visualized by means of 3D reconstruction. In CT, the bullet types differed in several fragmentation parameters. While the expanding full-copper bullet Ecostrike left behind only a single fragment near the end of the bullet channel, the soft-point Oryx had hundreds of fragments deposited throughout the channel. For both expanding bullets Ecostrike and Oryx, the fragments were clearly smaller than those left behind by the full metal-jacketed Jaktmatch. This was surprising as the full metal-jacketed bullet was expected to remain intact. The fragment cloud of Jaktmatch had similar mediolateral and superoinferior diameters to that of Oryx; however, fragments were deposited in the second half of the gelatine block, and not throughout the block. This case study provides a basis and potential methodology for further experiments. The findings are expected to benefit forensic practitioners with limited background information on gunshot injury cases, for example, those that involve several potential firearms or atypical gunshot wounds. The findings may prove beneficial for both human and wildlife forensics.

Cutaneous skin defects overlying tangential gunshot wounds: A case series.

In examining deaths resulting from gunshot wounds, it is important to describe the wound pathway created by the projectile. Forensic pathologists must identify all entrance and exit wounds and account for all projectiles. Occasionally, confusion arises as to whether a skin defect represents an entrance wound or not, an exit wound, or some other type of wound. Herein, we propose the descriptor "bullet track skin defect" as a formal description for a superficial skin defect created along the pathway of a projectile within the body. Specifically, we define the "bullet track skin defect" as a partial- or full-thickness skin defect produced by a projectile traveling beneath the skin in a relatively tangential fashion as part of a wound pathway within the body. It is somewhat analogous to a traditional graze or superficial tangential wound, wherein the projectile traveling outside the body strikes the skin tangentially from above, without entering the body. However, the projectile is already traveling within the body with the bullet track skin defect, disrupting the skin tangentially from below rather than from above, without exiting the body. Although these defects are not a common presentation of gunshot wounds, they are certainly not rare. With this case series, we suggest that such defects may be referred to as "bullet track skin defects." Alternative language that can substitute for "bullet track skin defects" includes "bullet track skin wounds" or "bullet track cutaneous defects."

Traumatic injuries by conducted electrical weapons: Case report of self-injury to the hand during stun gun training.

The use of non-lethal weapons has spread worldwide, being introduced as an alternative to firearms in many countries such as the United States or the United Kingdom. Among non-lethal weapons, conducted electrical weapons have been adopted worldwide, to control unruly suspected criminals or to neutralise violent situations. The stun gun belongs to this category and is the most widely available, with more than 140,000 units in use by police officers in the field in the US, and an additional 100,000 electrical stun guns owned by civilians worldwide. In Italy, the use of conducted electrical weapons by law enforcement has only recently been introduced, with private use and commercialisation still prohibited, mainly due to controversies related to the potential dangers of such devices.Before the official adoption, several experiments had to be carried out, with mechanisms that reproduced the ballistics of the stun gun. Here we present the case of a man who suffered a self-injury trauma to his hand during a ballistics exercise with a crossbow loaded with stun gun probes.

Heridas por proyectil de arma de fuego. Atipicidad en orificios de entrada y el fenómeno de ''cola de cometa": Reporte de caso / Gunshot wounds. Atypicality in entry holes and the "comet tail" phenomenon: Case report

El análisis de los orificios de entrada por proyectil de arma de fuego en una autopsia médico legal representa un importante papel en la determinación de la forma y causa de muerte en casos relacionados con armas de fuego. Su valoración puede proporcionar información valiosa sobre las características del arma utilizada, la distancia entre el arma de fuego y la víctima, entre otros factores que contribuyen a la investigación. El fenómeno de ''cola de cometa" observado en ciertos orificios de entrada es poco frecuente y conocido. Por lo anterior, el objetivo de este artículo es investigar las características y mecanismos de producción de los orificios de entrada con este fenómeno, proporcionando información sobre su formación, las posibles implicaciones y consideraciones médico legales a tomar en cuenta para su diagnóstico de esta causa de muerte. Se presenta un reporte de caso que destaca la descripción del fenómeno de ''cola de cometa" en una investigación forense de la vida real, proporcionando información valiosa sobre su utilidad y potencial para mejorar la precisión del análisis de heridas de bala. Se realizó revisión de artículos científicos, sobre orificios de entrada en heridas por proyectil de arma de fuego con el fenómeno de ''cola de cometa".

The analysis of firearm projectile entry holes in a medicolegal autopsy plays an important role in determining the manner and cause of death in cases involving firearms. The assessment can provide valuable information about the characteristics of the weapon used, the distance between the firearm and the victim, among other factors that contribute to the investigation. The ''comet tail" phenomenon observed in certain entry holes is rare and well known. Therefore, the objective of this article is to investigate the characteristics and mechanisms of production of the entrance orifices with this phenomenon, providing information about their formation, the possible implications, and medical-legal considerations to be taken into account for the diagnosis of this cause of death. A case report is presented highlighting the description of the ''comet tail" phenomenon in a real-life forensic investigation, providing valuable insight into its utility and potential to improve the accuracy of gunshot wound analysis. A review of scientific articles was carried out on entry holes in gunshot wounds with the "comet tail" phenomenon.

[War wounds and ballistics]. / Plaies de guerre et balistique.

Ballistic wounds, which historically concerned military populations, now also affect civilian practice. Terrorist attacks, urban violence and certain accidents have brought them into the daily routine of some French hospitals. Their frequency fully justifies the need for every health-care professional to be aware of the major issues involved in their management. In this section, we will describe the various penetrating ballistic wounds and their specific features. We will also rectify certain preconceived ideas that should not be peddled by healthcare professionals, in order to maintain a high standard of care.

[Ballistic wound in the pre-hospital and emergency room: Damage Control Resuscitation]. / Plaies balistiques en préhospitalier et aux urgences : Damage Control Resuscitation.

Damage Control Resuscitation (DCR) is a strategy designed to prioritize hemostasis procedures, from the point of injury to surgical management, whether faced with an influx of bleeding casualties or a single casualty with severe hemodynamic instability. Widely disseminated, it provides clear objectives for prioritizing physiological restoration to the anatomy required for short-term survival. Initially applied to surgery, DCR has now been extended to the entire upstream care chain, including first aid and emergency medicine.

[Orthopedic ballistic injury, a five-beat waltz]. / Blessé balistique orthopédique, une valse à cinq temps.

Two-thirds of ballistic injuries result in severe limb damage. Damage Control Orthopaedic is a surgical strategy that makes it possible to save life, limb and function using simple mnemonic markers: 5minutes, 6hours, 7 days, 8 weeks and 9 months. The many players involved in this coherent care pathway, with its multiple surgical challenges, help to meet the challenge of comprehensive rehabilitation for orthopaedic ballistic injuries.

Two case reports of fatal injuries sustained from tear gas guns loaded with pebbles as missiles.

These two case reports are of fatal injuries from less-lethal weapons (tear gas guns) using pebbles as an unconventional ammunition. Reported here are the fatal outcomes of two 19-year-old males, one with head trauma and the other with abdominal trauma. They were admitted to the ED and subjected to immediate exploratory operations, but they passed away. On autopsy, the first case demonstrated a right frontal bone fracture with subdural hemorrhage and a 3 × 2.5 cm pebble retained in the skull. The second case showed severe liver laceration in close vicinity to a cubical pebble (3.2 × 3 cm). The mechanical forces involved in skull fracture and autopsy are discussed. In the current cases, the relatively larger weight and size together with the surface configuration of the pebble projectile were the main influential factors that contributed to the severity of damage and fatality.These case reports are a working example of the effect of the mass of projectiles in increasing the power of penetration. The direct shooting to the head and the abdomen together with the misuse of these weapons are capable of inflicting fatal injuries.

Modeling of Ammunition Dynamic Pressure Measurement Chain in Ballistic Tests.

The use of piezoelectric transducers for internal dynamic pressure measurements in ammunition testing provides a significant advantage in the development and performance analysis of weapons and ammunition. Knowledge of the electrical characteristics of the dynamic pressure measurement chain, which includes the piezoelectric transducer and the charge amplifier, is a relevant condition for the design of interior ballistics pressure measurement systems. Thus, this study aims to characterize and model a piezoelectric transducer and its associated charge amplifier. First, the piezoelectric transducer was characterized using impedance analysis and modeled using a least squares curve-fitting tool, according to the Butterworth-Van Dyke model. Next, the charge amplifier was characterized through response analysis based on known inputs and modeled using LTSpice simulation techniques and the least squares curve-fit tool. Consequently, a measurement chain model is presented and simulated for two cases with different impulse signals. The first impulse signal was obtained from an interior ballistics computer simulation, and in the second case, it was considered the negative step signal characteristic of the calibration of piezoelectric transducers by means of dead weight. From the simulations, it was possible to verify the effectiveness of the model, which provided results with a low error in relation to the original pressure curve, and its applicability is demonstrated by the result of the simulation of the pressure variation in the calibration, where the attenuation of the signal can be visualized as the characteristic of the input curve changes.

Bursting of the upper jaw prosthesis and fractures of the lower jaw as indirect injury pattern caused by a headshot: a case report.

Gunshots to the human body can cause direct and indirect injuries. Direct injuries are a consequence of the projectile guiding its way through the body, creating a permanent wound channel and thereby damaging the penetrated as well as the adjacent tissue. In addition, the temporary wound cavity is responsible for indirect injuries occurring distant to the actual wound tract. This can potentially affect different types of tissue, like blood vessels, organs, or bones, that are not directly passed through by the projectile. For this case report, we describe a suicidal headshot to the temporal area where the extension of the temporary wound cavity and its subsequent collapse led to massive energy transfer to the surrounding tissue leading to breakage of the upper dental prosthesis and fractures of the lower jaw. Thereby outlining the ballistic mechanisms causing indirect injury pattern that have to be considered when examining gunshot wounds.

Pronking and bounding allow a fast escape across a grassland populated by scattered obstacles.

Some quadrupeds have evolved the ability of pronking, which consists in leaping by extending the four limbs simultaneously. Pronking is typically observed in some ungulate species inhabiting grassland populated by obstacles such as shrubs, rocks and fallen branches scattered across the environment. Several possible explanations have been proposed for this peculiar behaviour, including the honest signalling of the fitness of the individual to predators or the transmission of a warning alert to conspecifics, but so far none of them has been advocated as conclusive. In this work, we investigate the kinematics of pronking on a two-dimensional landscape populated by randomly scattered obstacles. We show that when the density of obstacles is larger than a critical threshold, pronking becomes the gait that maximizes the probability of trespassing in the shortest possible time all the obstacles distributed across the distance fled, and thus represents an effective escape strategy based on a simple open-loop control. The transition between pronking and more conventional gaits such as trotting and galloping occurs at a threshold obstacle density and is continuous for a non-increasing monotone distribution of the height of obstacles, and discrete when the distribution is peaked at a non-zero height. We discuss the implications of our results for the autonomous robotic exploration on unstructured terrain.

Multi-Layer Fabric Composites Combined with Non-Newtonian Shear Thickening in Ballistic Protection-Hybrid Numerical Methods and Ballistic Tests.

Multi-layer fabrics are commonly used in ballistics shields with a lower bulletproof class to protect against pistol and revolver bullets. In order to additionally limit the dynamic deflection of the samples, layers reinforced with additional materials, including non-Newtonian fluids compacted by shear, are additionally used. Performing a wide range of tests in each case can be very problematic; therefore, there are many calculation methods that allow, with better or worse results, mapping of the behavior of the material in the case of impact loads. The search for simplified methods is very important in order to simplify the complexity of numerical fabric models while maintaining the accuracy of the results obtained. In this article, multi-layer composites were tested. Two samples were included in the elements subjected to shelling. In the first sample, the outer layers consisted of aramid fabrics in a laminate with a thermoplastic polymer matrix. The middle layer contained a non-Newtonian shear-thickening fluid enclosed in hexagonal (honeycomb) cells. The fluid was produced using polypropylene glycol and colloidal silica powder with a diameter of 14 µm in the proportions of 60/40. The backing plate was made using a 12-layer composite made of Twaron® para-aramid fabrics with a DCPD matrix-not yet used in a wide range of ballistics. Then, numerical simulations were carried out in the Abaqus/Explicit dynamic analysis. The Johnson-Cook constitutive strength model was used to describe the behavior of elastic-plastic materials constituting the elements of the projectiles. For the non-Newtonian fluid, a Up-Us EOS was used. The inner layers of the fabric were treated as an orthotropic material. Complete homogenization of the sample layers was carried out, thanks to which each layer was treated as a homogeneous continuum. As a parameter of fracture mechanics for shield components, the strain criterion was used with the smooth particles hydrodynamics method (SPH). Then, the results of simulations were compared with the results of the ballistic test for both samples placed next to each other, which resulted in the formation of a multi-layer composite in one ballistic test subjected to impact loads during firing with a 9 × 19 mm Parabellum FMJ projectile with an initial velocity of 370 ± 10 m/s. The results of numerical tests are very similar to the ballistic tests, which indicates the correct mapping of the process and the correct conduct of layer homogenization. The applied proportions of the components in the non-Newtonian fluid allowed a reduction in the deflection compared to previous studies. Additionally, the proposal to use a DCPD matrix allowed to obtain a much lower deflection value compared to other materials, which is a novelty in the field of production of ballistic shields.