RESUMEN
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.
Asunto(s)
Balística Forense , Heridas por Arma de Fuego , Humanos , Heridas por Arma de Fuego/patología , Heridas por Arma de Fuego/diagnóstico por imagen , Balística Forense/métodos , Porcinos , Animales , Muslo/lesiones , Armas de Fuego , Polonia , Fémur/lesiones , Fémur/diagnóstico por imagen , Fémur/patologíaRESUMEN
Introduction: The development of pneumatic shooting has led to the construction of technologically advanced devices with discharge energies similar to those of firearms. The pneumatic weapons ammunition market offers a variety of shot which varies in penetration properties and the extent of gunshot damage. In view of the ease of "tuning" of air rifles, a study was conducted of the inlet damage to the anterior femoral surface after pneumatic gunshots. The paper shows the differences in damage parameters depending on the type of shot. Material and methods: In the study, Air Arms Hi-Power Xtra FAC cal. 5.5 mm and FX Bobcat Mk II cal. 6.35 mm pneumatic carbines were used and lead shot by Haendler&Natterman's Spitzkugel type, Hollow Point and Baracuda cal. 5.5 mm and 6.35 mm, as well as lead-free shot Excite Apollo cal. 5.5 mm and Black Max Lead-Free cal. 6.35 mm. Measurements were taken of the extent of inlet damage to the anterior surface of the femoral shaft with X-ray and CT imaging. Results: HollowPoint shot caused the greatest range of gunshot penetration damage in both bone and periosteum, Apollo lead-free shot caused the least. At the same time, HollowPoint shot showed the greatest susceptibility to ricocheting. Conclusions: 1. The type of shot used influences diversified morphology of the holes and the nature of gunshot damage to the femoral shaft. The differences concern both the gunshot holes and the nature, course and extent of associated fractures. 2. The smallest inlet holes and damage to the periosteum with a regular shape are caused by gunshots with pointed and pointed tip pellets. The greatest extent of bone and periosteum inlet damage was observed in gunshots with Hollow Point type shot due to its predisposition to deformation and fragmentation. 3. Radio-imaging studies are a valuable complement to macroscopic visual assessment providing a useful value for identifying the type of shot used.
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Armas de Fuego , Balística Forense , Heridas por Arma de Fuego , Humanos , Heridas por Arma de Fuego/diagnóstico por imagen , Heridas por Arma de Fuego/patología , Balística Forense/métodos , Fémur/lesiones , Fémur/patología , Fémur/diagnóstico por imagen , Muslo/lesiones , Muslo/diagnóstico por imagen , Fracturas del Fémur/diagnóstico por imagen , Fracturas del Fémur/patologíaRESUMEN
During the investigation of firearm-related incidents, gunshot residues (GSR) can be collected on the scene and individuals (e.g., shooters or bystanders). Their analysis can give valuable information for the reconstruction of the events. Since GSR collection on persons of interest generally occurs a few minutes to hours after discharge, knowledge is needed to understand how organic (O), and inorganic (I) residues are transferred and persist. In this research, the quantities of OGSR and IGSR were assessed on the right and left hands, forearms, face, and nostrils of four shooters. Specimens were collected immediately before the discharge (shooter's blank specimens) and shortly after (30 min) using carbon adhesive stubs. Organic compounds were first extracted from the collection device and analysed using ultra-high-performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS). Subsequently, IGSR particles were detected on the same stub using scanning electron microscopy coupled with energy-dispersive X-ray spectrometry (SEM/EDS). Shooter's blank specimen analysis revealed background contamination of both O and IGSR in the shooter's environment, predominantly attributed to the presence of an indoor shooting range. However, the background quantities generally remained below the associated 30-minute specimen. Thirty minutes after a discharge, higher quantities were generally detected on the shooter's right and left hands than on other collection regions for both GSR types. Forearms and face emerged as interesting collection alternatives, especially in cases where a person of interest may have washed their hands in the interval between the discharge and collection. In contrast, very low amounts of GSR were detected in the nostrils. Furthermore, the results indicated that OGSR and IGSR have different transfer and persistence mechanisms.
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Armas de Fuego , Balística Forense , Mano , Humanos , Balística Forense/métodos , Cara/anatomía & histología , Microscopía Electrónica de Rastreo , Espectrometría por Rayos X , Nariz , Antimonio/análisis , Antebrazo , Espectrometría de Masas en Tándem , Bario/análisis , Heridas por Arma de Fuego , Cromatografía Líquida de Alta Presión , CiclohexanonasRESUMEN
BACKGROUND: Although gunshot wounds are less common in Germany than in other countries, a proportion of suicides and violent crimes are committed with firearms, which is why basic knowledge of diagnosis is important. OBJECTIVE: Fundamentals regarding forensic assessment of gunshot wounds are discussed alongside typical radiological findings. MATERIALS AND METHODS: In addition to analyzing our own cases and evaluating official statistics, this article is based on a discussion of basic research and expert recommendations. RESULTS: The article describes the characteristics of the bullet entry and exit as well as special features of the bullet trajectory, particularly in bony injuries, and discusses their significance for radiological findings. Pitfalls in interpretation, such as changes in body position and the deflection of projectile (fragments) in the body, are presented, as are the advantages of supplementary radiological diagnostics (projectile search before initiation of dissection, simple detection of an air embolism, clarity of bullet trajectory reconstruction). CONCLUSION: This article is intended to provide an overview of not only typical types of weapons and projectiles but also their effects on the body of the victim, which must be documented by the examiner.
Asunto(s)
Balística Forense , Heridas por Arma de Fuego , Heridas por Arma de Fuego/diagnóstico por imagen , Humanos , Balística Forense/métodos , Alemania , Radiografía/métodosRESUMEN
In conventional gunshot injuries to targets containing bone the resulting osseous fragments do not precede but follow the bullet on its further way through adjacent soft tissues. The term "secondary projectiles" for the particles does not appear to be appropriate since they are not believed to have enough energy necessary for creating their own wound channels away from the temporary cavity. Former studies have shown that in angled shots to glass panes the bulk of splinters does not follow the bullet's trajectory: The majority of the glass fragments, especially the larger ones, move at right angles to the pane shot through. The aim of the presented study was to examine whether osseous fragments behave like glass splinters in angled shots to flat synthetic bone. In this context, it should also be assessed, whether the bone fragments might act as secondary projectiles in rare cases. To answer these questions, test shots were fired to composite models consisting of flat synthetic bone and ballistic gelatin. Pistol cartridges 9 mm Luger were used to fire the shots which were video-documented with a high-speed camera. Afterwards, the composite models underwent CT examination and macroscopic inspection. Video-documentation revealed that the larger bone particles from the perforation site move at a roughly right angle from the osseous sheet into the gelatin, causing an eccentric bulge of the temporary cavity. The smaller bone fragments were also lodged along the bullet's path, predominantly in the cracks radiating from the permanent wound channel.
Asunto(s)
Placas Óseas , Balística Forense , Heridas por Arma de Fuego , Heridas por Arma de Fuego/patología , Balística Forense/métodos , Humanos , Gelatina , Huesos/lesiones , Huesos/patología , Tomografía Computarizada por Rayos X , Grabación en VideoRESUMEN
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.
Asunto(s)
Balística Forense , Gelatina , Imagenología Tridimensional , Tomografía Computarizada por Rayos X , Heridas por Arma de Fuego , Balística Forense/métodos , Heridas por Arma de Fuego/diagnóstico por imagen , HumanosRESUMEN
Background: The use of radiological approaches in forensic investigations is rapidly emerging as an alternative to traditional autopsies. Here, we present the experience of the Sicilian and Calabrian forensic medical departments over the past five years, highlighting the application of PMCT to support autopsies in cases involving gunshot wound victims. Materials and Methods: From January 2020 to March 2024, thirty cadavers who died from gunshot wounds underwent total body PMCT examinations followed by autopsies. The examinations included multi-planar and 3D reconstructions. Data collected for each subject included gender, age, mode of death, type of weapon, number of shots, body sites affected, and presence of retained bullets. A team of two radiologists and two forensic physicians evaluated the images and compared them with the autopsy findings. Conclusion: PMCT and 3D reconstruction enabled evaluation of entry wounds, fracture margins, injury sites, fragments, and anatomical trajectories. The results from PMCT were compared with autopsy findings in terms of entry wounds, wound channels, foreign bodies, organ and skeletal injuries, and causes of death. PMCT showed concordance with autopsy findings in determining the cause of death in all cases. The speed, non-invasiveness, and ability to manipulate and reconstruct data make PMCT an ideal technique for supporting forensic investigations and autopsies. PMCT is highly reliable for accurately identifying lethal wounds and determining the cause of death. It excels at tracking wound paths, distinguishing entrance and exit wounds, locating retained bullets, and detecting fragmentation and dispersion of ballistic components.
Asunto(s)
Autopsia , Heridas por Arma de Fuego , Humanos , Heridas por Arma de Fuego/diagnóstico por imagen , Masculino , Autopsia/métodos , Femenino , Persona de Mediana Edad , Adulto , Anciano , Imagenología Tridimensional , Adulto Joven , Adolescente , Tomografía Computarizada por Rayos X , Cadáver , Balística Forense/métodosRESUMEN
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.
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Balística Forense , Pulmón , Cambios Post Mortem , Heridas por Arma de Fuego , Humanos , Balística Forense/métodos , Heridas por Arma de Fuego/patología , Pulmón/patología , Músculo Esquelético/patología , Músculo Esquelético/lesiones , Temperatura , Abdomen , Australia , Microscopía , MasculinoRESUMEN
The analysis of traces of injuries can be difficult in cases of charred human remains since the alteration and fragmentation are high. The aim of this study is to explore the use of X-Ray Fluorescence (XRF) technique as a screening tool for detecting and analyzing gunshot residues (GSR) on cremated and highly fragmented materials, as it is a technique that allows for fast qualitative investigations without altering the sample or requiring sample preparation. The study was carried out on two steps: firstly, on completed skeletonized bones to verify if GSR survive to burning; secondly, we considered a more realistic situation, in which soft tissues were present before the shooting. To this aim, nine adult bovine ribs, four retaining soft tissue, five completely skeletonized, were subjected to a shooting test using two types of 9 mm projectiles (jacketed and unjacketed bullets). The ribs were then burnt until complete calcination in an electric furnace. The entry wound of each rib was analyzed using XRF, revealing traces of GSR. The XRF analysis showed that all samples, except for one, contain Pb and/or Sb near the lesion. Furthermore, the samples hit by unjacketed bullets had a more significant presence of Pb in macroscopic yellow areas, which persisted when moving away from the gunshot. These findings could pave the way for the use of XRF technology, mostly when a fast and immediate scan must be done on osteologic materials by a conservative method.
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Antimonio , Balística Forense , Plomo , Costillas , Espectrometría por Rayos X , Heridas por Arma de Fuego , Heridas por Arma de Fuego/patología , Animales , Espectrometría por Rayos X/métodos , Costillas/lesiones , Costillas/química , Bovinos , Balística Forense/métodos , Plomo/análisis , Antimonio/análisis , CremaciónRESUMEN
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.
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Balística Forense , Gelatina , Heridas por Arma de Fuego , Balística Forense/métodos , Humanos , Modelos BiológicosRESUMEN
A smoothbore musket firing a round ball was the primary weapon of the infantry from the 16th to mid 19th century. Musket ball injuries are thus relatively common when archaeological remains of battlefield victims from that period are studied. Several experimental studies have focused on terminal ballistics of a musket ball. In addition, there is a good supply of historical records directly from the battlefield and military hospitals. Studies and historical records have both concluded that head injuries are among the most lethal types of musket ball damage. In this study we utilized modern day research methods, including Synbone ballistic skull phantoms and computed tomography (CT) imaging, to examine more closely the head injuries and tissue damage caused by a musket ball. We were especially interested to observe how different musket ball velocities and shooting distances would influence bone and soft tissue defects. Our experiments clearly demonstrated that musket ball was a lethal projectile even from a longer distance. Already at low velocities, the musket ball perforated through the skull. Velocity also influenced the appearance of entrance and exit wounds. CT imaging provided us with a three-dimensional view of the wound channel, skull fragments and lead remnants inside the skull phantom. According to our findings, musket ball velocity influenced defect size and cavitation. In addition, velocity influenced the size and distribution of skull fragments and lead remnants in the wound channel. Combining all these aspects could aid us in studies of archaeological musket ball victims. In particular, they could help us to estimate the shooting distance and shed light on the potential course of events in the battlefield.
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Balística Forense , Tomografía Computarizada por Rayos X , Humanos , Balística Forense/métodos , Heridas por Arma de Fuego/diagnóstico por imagen , Cráneo/diagnóstico por imagen , Cráneo/lesiones , Traumatismos Penetrantes de la Cabeza/diagnóstico por imagen , Traumatismos Penetrantes de la Cabeza/historia , Traumatismos Penetrantes de la Cabeza/patología , Armas de Fuego , Fantasmas de ImagenRESUMEN
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.
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Balística Forense , Gelatina , Piel , Heridas por Arma de Fuego , Heridas por Arma de Fuego/patología , Balística Forense/métodos , Humanos , Piel/lesiones , Piel/patología , Látex , Siliconas , Modelos Biológicos , DurezaRESUMEN
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.
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Balística Forense , Modelos Animales , Heridas por Arma de Fuego , Animales , Porcinos , Balística Forense/métodos , Heridas por Arma de Fuego/patología , Costillas/lesiones , Costillas/patología , Armas de FuegoRESUMEN
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.
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Alginatos , Armas de Fuego , Balística Forense , Gelatina , Heridas por Arma de Fuego , Balística Forense/métodos , Humanos , Heridas por Arma de Fuego/patología , Coloración y Etiquetado , Ácido Glucurónico , Manchas de Sangre , Ácidos HexurónicosRESUMEN
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.
Asunto(s)
Balística Forense , Heridas por Arma de Fuego , Humanos , Balística Forense/métodos , Heridas por Arma de Fuego/patología , Masculino , Persona de Mediana Edad , Fracturas Conminutas/patología , Adulto , Anciano , Femenino , Fracturas del Fémur/patologíaRESUMEN
Human surrogates have long been employed to simulate human behaviour, beginning in the automotive industry and now widely used throughout the safety framework to estimate human injury during and after accidents and impacts. In the specific context of blunt ballistics, various methods have been developed to investigate wound injuries, including tissue simulants such as clays or gelatine ballistic, physical dummies and numerical models. However, all of these surrogate entities must be biofidelic, meaning they must accurately represent the biological properties of the human body. This paper provides an overview of physical and numerical surrogates developed specifically for blunt ballistic impacts, including their properties, use and applications. The focus is on their ability to accurately represent the human body in the context of blunt ballistic impact.
Asunto(s)
Balística Forense , Modelos Biológicos , Humanos , Balística Forense/métodosRESUMEN
Shots with two different calibres (0.32 Auto and 9 mm Luger) were fired through phantoms that simulated human torsos, mounted on undercarriages with witness panels. The perforated phantoms were scanned with computed tomography (Siemens) using 80 kV and 140 kV and a slice thickness of 1 mm. The intracorporeal trajectories in the phantoms were compared to the known extracorporeal trajectories, derived from the perforations in witness panels. The discrepancy between the intracorporeal and extracorporeal trajectories, denoted as the absolute angle, was calculated for the trajectories before (front) and after (rear) the phantoms. Mean absolute angles at the front were lower than at the rear (2.27° vs. 4.54°) and the difference was statistically significant (p < 0.001). The results of the study imply that the line between the entrance and the exit wound in a scanned victim can be extended to the extracorporeal bullet trajectory leading towards the entrance wound. The absolute angles presented in this study give an impression of the expected errors with the two calibres. This can be helpful in shooting investigations to assess the position of the shooter from entrance and exit wounds in a scanned victim.
Asunto(s)
Balística Forense , Fantasmas de Imagen , Tomografía Computarizada por Rayos X , Heridas por Arma de Fuego , Humanos , Heridas por Arma de Fuego/diagnóstico por imagen , Balística Forense/métodos , Armas de FuegoRESUMEN
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.