Case Report of a Migrating Bullet: An Unusual Cause of Postmortem Confusion

Migrating bullets are rare sequelae of penetrating gunshot wounds. Such cases have been described in the neurosurgical literature because they can produce complications in the management of patients such as decline in neurologic status, delays in rehabilitation, and difficulties in bullet removal. In contrast, few postmortem reports have described this phenomenon. We report a case of a gunshot wound in which the projectile entered the left side of the head and traversed to the right frontal area as documented by CT scan on hospital admission. At autopsy, the bullet was noted to have migrated back to the left side of the head from where it was recovered. Medical examiners need to be aware of this unusual phenomenon of retained intracranial projectiles.     

Postmortem Computed Tomography and Magnetic Resonance Imaging of Gunshot Wounds to the Neck

Postmortem magnetic resonance imaging (MRI) is rarely used for the radiologic assessment of gunshot injuries, although it has clear advantages over postmortem computed tomography (CT) with regard to the imaging of soft tissue injuries. Another benefit in using MRI is that lodged projectiles composed of nonferromagnetic material such as lead present only marginal metal artifacts compared with severe artifacts on CT. This case report presents CT and MRI findings in a case with two gunshot wounds to the neck: a perforating wound and a nonperforating wound with a lead bullet lodged in the cervical spine. The decedent underwent CT and MRI before the scheduled autopsy. A ring of radiopaque material under the dermis in the fatty tissue was identified at both entrance wounds on CT, which was indicative of contact shots. The perforating gunshot was clearly indicated on CT by bullet fragments along the wound channel through the perforated 6th cervical vertebra and the fractured cricoid cartilage at the exit wound. The second trajectory, however, was only assumed based on the presence of gunshot residues at the entrance wound and the position of the lodged bullet. The radiologic assessment was severely impeded by the metal artifacts on CT. Barely noticeable metal artifacts on MRI allowed for clear visualization of the soft tissue injuries and the ruptured medulla oblongata. Only MRI clarified the soft tissue injuries of the brainstem noninvasively, which could provide specific and graphic information on the rapidity of death and the incapacitation of the victim.     

Immunocytochemical examinations of biological traces on expanding bullets (QD-PEP)

When a crime victim has been injured with several different objects, it is of central importance for the forensic investigation to be able to show which object caused which injury, especially if one of the injuries was lethal. In cases of bullet penetration wounds it is often not possible to find such evidence. However, immunocytochemical investigations can accurately match a victim's injury to a particular bullet path through the body. In cases where expanding bullets have been used and the heart or liver has been struck by a projectile, it can be shown that the cells remaining on the bullet stem from those particular organs. In this case the specific cytological evidence was established by means of marking heart- and liver-specific tissue proteins with appropriate antibodies (cardiac troponin I and HepPar 1) followed by disclosure with an appropriate chromogen. Thus, in principle, cells can be used as evidence after being extracted from the projectiles by either damp cotton-wool swabs or adhesive trace evidence tape. Because of the specificity of the used immunocytochemical antibodies, finding evidence of an antigen on a particular projectile proves that it was the object that injured the organs.     

Gunshot entrance wound abrasion ring width as a function of projectile diameter and velocity

The relationships between gunshot entrance wound abrasion ring widths versus projectile diameter and velocity, using foam-backed deer hides as targets, were investigated. At a fixed velocity, abrasion ring width increased with increasing projectile diameter but decreased in proportion to the central defect diameter. For fixed-diameter projectiles, very slow and high velocities produced minimal abrasion width. Maximal abrasion width occurred at intermediate velocities. The authors postulate that abrasion width is a function of the ratio of projectile velocity and the maximum deformation velocity of the target skin. The largest abrasion width occurs when the ratio is one. Using a projectile velocity known to produce maximum abrasion width at an initial warm temperature, then decreasing the target deformation velocity by cooling, produced the expected results of decreasing abrasion width.     

A first time for everything: homicide involving the Brenneke SuperSabot shotgun slug

Sabot shotgun slugs are not a new projectile, but the Brenneke SuperSabot shotgun slug has never been reported in a homicide. We present the case of a 28-year-old man killed with multiple gunshot wounds during an alleged "drive-by" shooting. At autopsy, a 496.2 grain slightly deformed projectile with a base diameter of 5/8' (1.7 cm) was found within the decedent's clothing. Six distinct bullet tracks were identified. An entrance of the anterior right thigh was 3/4 x 5/8' and ovoid, having only passed through the decedent's jeans. This bullet track passed through the soft tissue of the right thigh, exiting out the medial aspect and partially transecting the right greater saphenous vein, re-entering the medial left thigh and re-exiting out the posterior left upper thigh. With the exception of an irregular entrance on the sole of the left foot, which passed through the decedent's shoe, all other entrances were less than 1/2' in greatest dimension. Investigating officers recovered an additional projectile of the same type, which had undergone more extensive deformation after striking and penetrating the tailgate of a truck. Further investigation identified the projectiles as the Brenneke SuperSabot shotgun slugs.     

Forensic imaging of projectiles using cone-beam computed tomography

In patients with gunshot injuries, it is easy to detect a projectile within the body due to the high-density of the object, but artefacts make it difficult to obtain information about the deformation and the exact location of the projectile in surrounding tissues. Cone-beam computed tomography (CBCT) is a new radiological imaging modality that allows radio-opaque objects to be localised and assessed in three dimensions. The full potential of the use of CBCT in forensic medicine has not yet been explored.In this study, three different modern projectiles were fired into the heads of pig cadavers (n = 6) under standardised conditions. Tissue destruction and the location of the projectiles were analysed separately using CBCT and multi-slice computed tomography (MDCT).The projectiles had the same kinetic energy but showed considerable differences in deformation behaviour. Within the study groups, tissue destruction was reproducible. CBCT is less severely affected by metallic artefacts than MDCT. Therefore CBCT is superior in visualising bone destruction in the immediate vicinity of the projectile and projectile deformation, whereas MDCT allows soft tissue to be evaluated in more detail.CBCT is an improved diagnostic tool for the evaluation of gunshot injuries. In particular, it is superior to MDCT in detecting structural hard-tissue damage in the immediate vicinity of high-density metal projectiles and in identifying the precise location of a projectile in the body.     

Scanning Electron Microscope Analysis of Gunshot Defects to Bone: An Underutilized Source of Information on Ballistic Trauma

Recent years have seen increasing involvement by forensic anthropologists in the interpretation of skeletal trauma. With regard to ballistic injuries, there is now a large literature detailing gross features of such trauma; however, less attention has been given to microscopic characteristics. This article presents analysis of experimentally induced gunshot trauma in animal bone (Bos taurus scapulae) using full metal jacket (FMJ), soft point (SP), and captive bolt projectiles. The results were examined using scanning electron microscopy (SEM). Additional analysis was conducted on a purported parietal gunshot lesion in a human cranial specimen. A range of features was observed in these samples suggesting that fibrolamellar bone response to projectile impact is analogous to that observed in synthetic composite laminates. The results indicate that direction of bullet travel can be discerned microscopically even when it is ambiguous on gross examination. It was also possible to distinguish SP from FMJ lesions. SEM analysis is therefore recommended as a previously underexploited tool in the analysis of ballistic trauma.     

Mechano- and morphogenesis of gunshot fractures in the flat bones

Gunshot fractures in flat bones, bullet defects in the continuum were studied in experiment. The laws of gunshot fracture formation were formulated. In far distance, bullet has a direct and radial blow action. The direct blow induces comminution and disintegration of the bone tissue with dislocation of bone fragments; radial blow potentiates bone destruction. Morphological characteristics of gunshot fractures of flat bones depend on the force of the direct and radial impact action and can be used for estimation of the far shot distance, kinetic energy and shape of the head of the shell.     

Ballistic impact of hollow-point ammunition on porcine bone

Identifying failure mechanisms in skeletal tissue allows a deeper understanding of the effects of specific projectile impacts on bone. While ballistic trauma in flat bones is largely researched, knowledge of how long bones react to gunshot impacts is limited in the literature. The impacts of deforming ammunition appear to produce higher levels of fragmentation; however, these have not been studied in depth. This study compares the damage to femora bone by HP 0.357 and 9 mm projectiles constructed with both full and semi-metal jackets. Impact experiments were undertaken on a single-stage light gas gun involving the use of a high-speed video camera and full reconstruction of the bones to ascertain fracture patterns occurring in the femora. Higher degrees of fragmentation are likened to the presence of semi-jacketed HP projectiles than jacketed HP projectiles. The observations of external facing beveled edges are believed to be associated with the increased separation of the jacket and lead core of projectiles. Additionally, experimentation has shown that the amount of kinetic energy lost postimpact is likely related to the presence or the absence of a metal jacket on an HP projectile. The observed data, therefore, suggest that the composition, rather than the configuration, of a projectile affects the type and extent of the damage.     

Morphological features of gunshot injuries of the cranial bones

Morphological characteristics of gunshot injuries of the cranial dome bones depend on bullet speed and are determined by various mechanisms of the harmful action. A contusion action of the bullet is characterized by disruption of the bone tissue with formation of linear or incomplete fracture. A wedged impact is accompanied with disruption of bone structures with formation of depressed or comminuted fractures due to radial dislocation of the fragments. A perforative impact produces a hole defect the shape of which depends on bullet speed. A bursting impact of the bullet causes disruption of the bone tissue outside the bullet defect as a result of an additional radial effect of high pressure of the air wave reaching in the wounds inflicted by high-speed bullets the effect of the hydrodynamic shock in the spongy layer of the flat bone. Resultant morphological manifestations are aggravated by damage caused by hydrodynamic shock coming from the cranial cavity.     

Use of scanning electron microscopy and energy dispersive X-ray analysis (SEM-EDXA) in identification of foreign material on bullets

The authors report two cases in which examination of foreign material embedded in or adherent to bullets provided critical information in the reconstruction of a crime scene. Analysis of small particles by scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDXA) can be accomplished without destruction or injury of the particles. In one case, the detection and identification of mineral fragments embedded near the nose of a bullet provided conclusive evidence that the bullet had ricocheted from a fireplace before striking the victim. In the second case, analysis of particles from two bullets identified them as them as bone fragments, thus proving which shots fired from a police officer's gun had killed a suspected burglar. SEM-EDXA has not been widely used to identify such material on bullets, but should be considered a potentially powerful tool in forensic science.     

The effects of certain intermediary target materials and their proximity to ballistic gelatin on jacketed hollow point bullet expansion

Expanding bullets are preferred by law enforcement because of their wounding potential and ability to avoid over-penetration which could result in unintended targets being struck by bullets that perforate their intended targets. Expansion failure for jacketed hollow point (JHP) bullets is commonly attributed to several causes including damage to the bullet's cavity, velocity loss, bullet destabilization and materials from intermediate targets filling the bullet's cavity which can cause expansion failure when the bullet subsequently impacts a soft, fluid-based target such as human tissue or ballistic gelatin. In this study, JHP bullets were fired into ballistic gelatin after passing through selected intermediate targets representing items common to shooting incidents. Velocity loss and bullet destabilization were not factors that contributed to the JHP bullets that experienced expansion failure; however, materials obstructing the bullets' cavities and damage to the bullets' cavities were considered causes for some of the JHP bullet expansion failures. It was determined through this research that most of the target materials caused JHP bullet expansion failure when shored against the ballistic gelatin, but when placed at distances of 7 ft. from the ballistic gelatin, bullets fired through the same target materials did expand. This original and unique study produced findings that are of significant value to shooting incident reconstruction experts and other forensic professionals as shooting incidents can call into question a victim's proximity to a wall or door when a bullet(s) perforated such a target material.     

Transfer and Distribution of Gunshot Residue through Glass Windows

Research into the deposition patterns of primer gunshot residue (GSR) beyond a primary target was previously nonexistent. This study aimed to determine the deposition patterns of GSR once a bullet passed through an initial target and continued on its path into additional targets. Multiple repetitions were performed to assess the GSR deposition patterns after a bullet was shot through a closed window into either a dummy or a wall within an enclosed room. Samples were taken from both the primary and secondary target holes as well as from nontarget areas. Significant amounts of GSR were found on all samples. The results show that GSR continues to be deposited along the path of the bullet after passing through a primary glass target. These findings reiterate the lack of probative value in collecting GSR samples from gunshot victims even if they are in an enclosed area separate from the shooter.     

Radiodense bullet wipe around osseous entrance gunshot wounds

“Bullet wipe” is the material deposited by a bullet on any surface with which it comes into contact after it is fired and may contain debris from the gun barrel, including particles of primer and metal fragments from previously fired bullets. X‐ray analysis is a non‐destructive method by which traces of metallic elements can be visually detected. The analysis of osseous defects for radiodense bullet wipe (RBW) assists in determining the presence or absence of perforating gunshot wounds, especially in fragmented, skeletonized remains. The aim of our current study was to determine the frequency of RBW around entrance firearms injuries that perforated bone. We prospectively analyzed entrance gunshot wounds for RBW over a three‐year period using digital X‐ray analysis (n = 59). We retrospectively reviewed the corresponding autopsy reports to determine the frequency of RBW by biologic sex, reported ancestry, age‐at‐death, location of wound, manner of death, range of fire, bullet caliber, and presence of bullet jacket. Data were analyzed by Fisher's exact test or Chi‐square test with significance levels accepted at p < 0.05. RBW was present in 66% (n = 39) of examined cases. Decedent characteristics did not significantly alter RBW distribution, including biologic sex (p = 0.75), reported ancestry (p = 0.49), and age‐at‐death (p = 0.43). Additionally, the location of the osseous entrance gunshot wound, manner of death, range of fire, and cartridge caliber did not affect RBW detection. All cases involving non‐jacketed rounds (n = 5) showed RBW (p = 0.30). To our knowledge, this study is the first to report the frequency of RBW detection from osseous entrance gunshot wounds.     

Abrasion Collar Around Shrapnel Entry Wound

Abrasion collar is usually described as a feature of bullet entry wounds caused by friction and indentation. The present case is that of the peculiar entry wound caused by a piece of flying shrapnel which was ejected from a furnace in a steel plant. The scrap metal which exploded in the plant was sourced from the West Asia region. The entry wound on the chest was circular and had an abrasion collar around it. The projectile was a cylindrical object of obscure origin. The forensic science laboratory put forth the possibility that the projectile was a component of an artillery fuze. A decades old study which employed high‐speed photography has rejected the possibility that abrasion collars are produced by friction. High‐velocity projectiles other than bullets can also produce abrasion collars as the rubbing of the bullet against the skin or its rotation are not the causative mechanisms.     

撞击角度和速度已知条件下的球形弹丸飞行弹道轨迹算法

针对刑侦工作中弹打玻璃类案件的侦破难点,研究一种用于计算球形弹丸抛射击打玻璃案件中弹丸飞行轨迹的算法。本文以弹丸撞击角度和撞击速度为基础参数,在阐明前置基础数据的前提下,将弹打玻璃类案件中的玻璃窗分为垂直于地面及倾斜于地面两类,采用三角函数计算和参数替换的方法,通过对弹丸撞击瞬间的弹道参数设定、弹孔图像在玻璃平面内的二维图像参数设定、相关角度的描述、计算抛物线轨迹与弹道轨迹朝向等一系列步骤,最终,研究出上述两类玻璃窗的弹道轨迹计算方法。研究表明,弹丸弹道飞行轨迹算法可以还原弹丸飞行的轨迹抛物线,作为现场弹道轨迹重建系统的核心算法使用,为开发弹打玻璃类案件的现场弹道轨迹重建系统提供了关键技术。     

Radiography of perforating centerfire rifle wounds of the trunk

All deaths resulting from perforating centerfire rifle wounds of the chest and abdomen, investigated by the Office of the Chief Medical Examiner for the Province of Alberta from 1988 to 1995. were reviewed retrospectively to determine whether the radiographic distribution of bullet fragments in such cases is a useful predictor of bullet trajectory. Study cases were limited to single gunshot wounds without surgical intervention or intermediate targets, and for which adequate radiography was available. Three pathologists individually viewed the radiographs on two separate occasions; wound locations were provided for the second viewing (Group 2). Differences in opinion regarding direction of fire were resolved by consensus review. A trauma radiologist independently made two sets of interpretations in the same way. Comparisons of these groups of interpretations were made with the actual bullet direction determined at autopsy. Of 21 cases included in the study, only three (14.3%) did not require consensus resolution in either group. Accuracy of pathologists' interpretation improved from 38.1% (8/21) to 76.2% (16/21) with provision of wound locations (p = 0.012). The radiologist achieved similar improvement, from 28.6% (6/21) to 47.6% (10/21). The rate of agreement between radiologist and pathologists increased from 42.9% (9/21) to 61.9% (13/21) between Groups 1 and 2. Both the pathologists and radiologist interpreted several cases the same way in both groups; of those cases interpreted differently, the second interpretation was occasionally incorrect after correct interpretation in Group 1. We conclude that bullet direction for perforating centerfire rifle wounds cannot be accurately determined from postmortem radiographs. When wound location is known, the ability to predict bullet direction improves but is still subject to error, including a lack of consistency between observers.     

The tubular "cookie cutter" bullet: a unique projectile

Recently marketed PMC (Pan Metal Corporation) Ultramag tubular hollow point ammunition is uniquely constructed with a two-part projectile composed of a tubular copper bullet and a Teflon wad. A fatal gunshot wound with this ammunition is described. A unique radiographic pattern and the results of test firing are also presented.     

Retrograde transthoracic venous bullet embolism. Report of a case following a single gunshot with multiple wounds in the left arm and chest

Bullet embolism of the arterial, venous and paradoxical types are well known but rare complications of penetrating missile injuries. Retrograde transthoracic venous bullet embolization is extremely rare with only four cases previously reported in the literature. Single gunshot can cause multiple wounds, mainly because the bullet passes through an intermediate target before striking the victim. We present the autopsy findings of a retrograde transthoracic bullet embolism to the right external iliac vein after a single gunshot with multiple wounds in the left arm and thorax. Problems related to medico-legal investigations of gunshots are reviewed.