Search

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. [ABSTRACT FROM AUTHOR]

In the frame of an experimental setting, the formation of round-shaped compounded glass fragments on the exit site after gunshots through a windshield was examined. For that purpose, a 9 × 19 mm pistol (HK P30) and two different cartridges containing (a) a full metal jacketed round-nosed projectile and (b) a deformation projectile were used. On the basis of 52 gunshots, the morphology, impact angles and terminal ballistics of occurring compounded glass fragments were examined. The results showed that the compounded glass fragments' morphology allowed for the differentiation of two used projectiles. Fragments were able to cause round-shaped defects in a single cotton layer (T-shirt) with subsequent penetration of up to 2.4 cm into ballistic gelatin (10%, 4 °C). As a function of the projectile type, the compounded glass fragments showed different reproducible impact angles that differed notably from the known conical pattern of expelled glass fragments after bullet penetration. These findings might help to explain the atypical morphology of gunshot wounds with laminated glass as an intermediate target and prevent possible misinterpretations when reconstructing the sequence of events. [ABSTRACT FROM AUTHOR]

The sodium rhodizonate test is a simple colorimetric technique used to identify traces of lead and barium. A positive test provides rapid and photographically documentable results for shots fired at distances not exceeding 50 cm. Usually, this method is not used for identification of the firing hand, which is detected by electron microscopy with energy dispersive analysis (SEM-EDX), requiring the removal of any particles on the surface to be analyzed by STUB. The use of Sodium Rhodizonate, which is undoubtedly less selective, has the disadvantage of target element solubilization (lead and barium) and thus the loss of the preliminary morphological investigation of the particles. The purpose of this paper is to demonstrate that the two indicated methods can be considered complementary in the following order: 1. buffer sampling for electron microscopy investigation (STUB); 2. and subsequent performance of the Sodium Rhodizonate Test. In some special cases, when it is necessary to obtain the result more quickly, with regards to respecting the chronology of the aforementioned tests, it may be useful to carry out the Sodium Rhodizonate Test first, especially when particular and perhaps antiquated weapons were used for suicidal purposes causing considerable gas dispersion and shot residues from the mechanisms. This research illustrates how significant results were obtained substantiating the suicide hypothesis, following the use of an old revolver (year of manufacture around 1915-1920). [ABSTRACT FROM AUTHOR]

Introduction: the present work is a review of forensic ballistics, forensic medicine, and papilloscopy. Its main focus is on the recovery of latent fingerprints in fired cartridge cases of firearms. Fundamentals of internal and intermediate ballistics are being exposed, as well as fundamentals of the anatomy of the integumentary system to explain the formation of the fingerprint. Finally, techniques of analysis of cartridge cases and the components of analysis are presented to point out the best ways to recover impressions of the shooter without, however, damaging or destroying important traces for the criminal investigation. It is important to highlight that this type of forensic methodology is practicable in the laboratory in a way that is not costly to the State and also allows quick and reliable results. Because it is a little explored topic, there was a need for this integrative review, given its importance for criminalistics and forensic sciences in general, especially forensic ballistics and forensic medicine. [ABSTRACT FROM AUTHOR]

Introduction: A comprehensive scene reconstruction requires forensic investigators to examine the impact marks left on various surfaces to identify whether a projectile produces a specific hole. Subsequently, it is further necessary to determine whether a particular ammunition has caused the impact. Throughout history, designs of ammunition have evolved with the intended effects, which could leave different impact marks on a target surface, especially by ammunition with a nonconventional design. Careful examination on impact marks and determination of their specific characteristics on sheet metal of vehicle would provide crucial forensic information. Aim: This study was aimed to physically characterize bullet impact holes made by 11 types of 9-mm caliber ammunitions. Materials and Methods: Two automotive doors were shot with different ammunitions from the same firearm, and the morphological features of bullet impact holes were observed and compared. Results: Bullet impact holes produced by the various ammunitions could be differentiated through careful observation of bullet hole circumferences, presence of petalling effect, metallic ring and triangular peak at the edge, and deposition of residue at the peripheral area of bullet impact holes. Ammunitions with nonconventional design such as Inceptor-Polycase and GECO Hexagon showed observable morphological differences and discriminated them from bullet impact holes made by conventional ammunitions. Conclusion: A thorough physical examination could aid in distinguishing bullet impact holes and predicting the possible types of ammunition that had made an impact hole on a surface. [ABSTRACT FROM AUTHOR]

• Bullet trajectories inside phantoms describe a straight line from entrance to exit wound. • The discrepancy between the intracorporeal and extracorporeal trajectories can be measured using angles. • Trajectories identified inside the phantom can be extended outside the phantom with a limited range of uncertainty for the two calibres used. • The findings above can be helpful in more accurate assessment of the position of a shooter in a shooting investigation. 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. [ABSTRACT FROM AUTHOR]

Introduction: firearm projectiles are the cause of head and neck injuries of large proportions. Therefore, investigating and describing the areas of the head and neck that are mostly affected by firearm projectiles is essential to determine a pattern of these injuries. This kind of investigation can be useful in forensic medicine to help elucidate and differentiate self-inflicted injuries compared to those accidental shots or homicides. Materials and Methods: systematic review based on the analysis of studies published in Portuguese, English, and Spanish, between 1989 and 2022, collected in the following databases: PubMed, Scopus, Embase, Web of Science, and Lilacs. Results: the search identified 47 articles, of which six studies met the inclusion criteria and were, therefore, used for data collection. In general, the literature indicates that the head and neck areas mostly affected by firearm projectiles are directly related to the cause of death. Conclusions: the present study provides evidence that proves the variation in the areas of the head and neck mostly affected by firearm projectiles according to the cause of death. [ABSTRACT FROM AUTHOR]

The incidence of civilian gunshot injuries is on the rise worldwide.Unfortunately, there is a lack of high-level evidence guiding management. The treatment of orthopaedic injuries from gunshots is complex and requires consideration of multiple aspects, including energy transfer to the tissue, severity of the wound, possible contamination, presence of fractures and associated injuries. With this narrative review we aim to discuss some of the relevant ballistics, current concepts, and controversies in the general management of civilian gunshot-related orthopaedic injuries based on the available evidence and personal experience. Important points which will be highlighted are the initial management in the emergency room, the assessment and management of soft tissue injuries, associated injuries, use of antibiotics, indication and techniques for fracture fixation, and gunshot injuries to joints. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Postmortem computed tomography (PMCT) is integrated into the evaluation of decedents in several American medical examiner offices and medicolegal death investigative centers in many other countries. We retrospectively investigated the value of PMCT in a series of firearm homicide cases from a statewide centralized medical examiner's office that occurred during 2016. Autopsies were performed or supervised by board‐certified forensic pathologists who reviewed the PMCT scans prior to autopsy. PMCT scans were re‐evaluated by a forensic radiologist blinded to the autopsy findings and scored by body region (head–neck, thoracoabdominal, and extremities). Injury discrepancies were scored using a modified Goldman classification and analyzed with McNemar's test. We included 60 males and 20 females (median age 31 years, range 3–73). Based on PMCT, 56 (79.1%) cases had injuries relevant to the cause of death in a single body region (24 head–neck region, 32 thoracoabdominal region). Out of these 56 cases, 9 had a missed major diagnosis by PMCT outside that region, including 6 extremity injuries visible during standard external examination. Yet all had evident lethal firearm injury. We showed that PMCT identifies major firearm injuries in homicide victims and excludes injuries related to the cause of death in other regions when a single body region is injured. Although PMCT has a known limited sensitivity for soft tissue and vascular pathology, it can be combined with external examination to potentially reduce or focus dissections in some of these cases depending on the circumstances and medicolegal needs. [ABSTRACT FROM AUTHOR]

When a bullet punctures a surface, it leaves behind a bullet impact, which can be analyzed in order to determine the origin and trajectory path from which a bullet was discharged using many different scientific methods to reconstruct a shooting scene. The purpose of the research was to test the accuracy and repeatability of reconstructing the impact angle of single bullet impacts using the ellipse method. The research was conducted by firing various calibers of ammunition into drywall panels positioned at varying angles of incidence from 88° until ricochet occurred. This was done in order to determine which caliber type and angle of incidence are most accurate and precise for reconstructing a shooting scene. The study examined four caliber types fired into drywall panels, with 5 repeated shots for each of the 11 angles of incidence (n = 220). Furthermore, 31 participants partook in the study to estimate a bullet impact angle of incidence utilizing the ellipse method. The results show that the best performance (accuracy and repeatability) is seen with the measurements of the 0.45 caliber ammunition. When angle of incidences is low (<64°), the performance (accuracy and repeatability) was seen to be better in all caliber ammunitions. Overall, the data provided for single bullet impacts deposited in drywall show that the ellipse method is useful in providing measurements for most crime scene reconstruction purposes and has also demonstrated that results vary depending on the type of ammunition, firearm, and angle of incidence being examined. [ABSTRACT FROM AUTHOR]

Increased stretch tolerance can contribute to improved range of motion (ROM). Since menthol-based topical analgesics (TopAnalg) suppress pain, they may increase stretch thresholds improving ROM. Other modalities such as transcutaneous electrical nerve stimulation and rolling have demonstrated decreased pain sensitivity in the contralateral limb. The purpose of this study was to investigate the effects of a TopAnalg on active and passive ROM of the treated and contralateral (untreated) leg. With a double blind, repeated measures design, 14 university students had a TopAnalg or a placebo gel applied to their hamstrings, rested for 20-min and then either performed static or dynamic stretching. Prior to gel application and after stretching, participants were tested for passive static, active and ballistic hip flexion ROM. Near significant greater ballistic hip flexion ROM for both legs (treated: p = 0.08; 3.6%; contralateral: p = 0.1; 1.6%) were observed with the TopAnalg. With dynamic stretching, ballistic hip flexion ROM of both limbs at post-test (p=0.01-0.007; 3.3-4.2%) and post-10 minutes (p = 0.06-0.01; 2.7-4.1%) decreased with the placebo, whereas there were no significant reductions with the TopAnalg. There was a near significant higher active hip flexion ROM (stretched leg: p = 0.05; 4.6%), and significantly higher ballistic hip flexion ROM (p = 0.04-0.05; 3.4-3.5%) with static versus dynamic stretching for both legs. In conclusion, TopAnalg can increase hip flexion ROM of the treated and contralateral limbs. Secondly, static stretching contributed to greater ballistic ROM in both the stretched and non-stretched contralateral limbs. Hence, TopAnalg may be used to enhance flexibility training with rehabilitation or highly trained athletes. [ABSTRACT FROM AUTHOR]

The authors describe a case in which a 21-year-old male committed suicide using a rifle equipped with a muzzle brake, placed in contact with his head. A muzzle brake for firearms is a device positioned at the mouth of a weapon, which dissipates the gases, that are generated subsequent to the gun being discharged. Generally, when a gun is pressed against an anatomical region, where the skin lies on the bone surface without interposition of other soft parts, the entrance wound consists of many lacerated branches, originating from a central lack of tissue. In this case report, the use of a rifle with a muzzle brake generated an unexpected wound, circular in shape, with a diameter of 0.8 cm. This lesion was surrounded by a bruised area, circular in shape, and an abrasion collar of the height of 0.5 cm. In addition, a muzzle imprint mark consisting of intradermal bruises, composed of a narrow red line concentrically encircling the entrance hole, was found. In order to analyze in detail if this particular entrance wound could be associated with a weapon equipped with the muzzle brake, ballistic tests – with weapons compatible with that used by the victim – were performed. [ABSTRACT FROM AUTHOR]

• X-ray analytic microscopy showed element distribution in a sample corresponding to a CT image. • CT-guided sample extraction allowed retrieval of likely true projectile fragments from tissues. • X-ray analytic microscopy and CT-guided sample extraction helped evaluate potential gunshot wounds. In forensic pathology, it is important to detect and recover as evidence residual metal particles and projectiles when evaluating potential gunshot wounds. This process can be challenging when the bullets are fragmented. This report presents our experience using multiple modalities to analyze the wound of an illegally killed Japanese serow (Capricornis crispus) found in a mountainous region without its head and hind limbs. We performed postmortem computed tomography (PMCT) and necropsy that showed a distant-range gunshot wound of the neck likely created by a centerfire rifle. A postmortem cut through the neck and absent head precluded a complete evaluation. To determine the composition of the metal-like fragments in the neck, sampling and metal analysis were performed in two ways. Samples extracted from the exposed wound surface without CT guidance were analyzed directly using inductively coupled plasma mass spectrometry (ICP-MS). Samples from the bone, muscles, and cervical cord extracted under CT guidance were analyzed using x-ray analytic microscopy (XGT-9000, HORIBA, Kyoto, Japan). In wound surface samples, silicon and iron were detected as the main components on ICP-MS, suggesting that the materials were gravel. The samples taken under CT guidance and analyzed with XGT-9000 revealed that the high-density CT areas were mainly composed of lead. Combining CT-guided sample extraction and XGT-9000 can be useful for retrieving true projectile fragments and avoiding the confusion created by erroneously sampling non-projectile surface materials. [ABSTRACT FROM AUTHOR]

Firearm discharge residue (FDR) contains organic and inorganic constituents that arise from the propellant; primer; and, to a lesser extent, the barrel, bullet, and casing. When a weapon is fired, residues are deposited on nearby surfaces with the hand being of primary forensic interest. Current methodology focuses on inorganic primer residues (IGSR) characterized using SEM/EDX. Advances in mass spectrometry have facilitated the detection of organic residues (OGSR) using variations of LC/MS and related ambient ionization methods. In the last few years, single sample collection has been used to characterize IGSR and OGSR via sample splitting and separate analysis by SEM and LC/MS. This paper presents an innovative approach in which IGSR and OGSR are collected on a single SEM stub sample, extracted in a two-step sequential process, and then characterized with a single instrument, LC coupled with triple quadrupole mass spectrometry. The key innovation is exploitation of host-guest and ligand chemistry to detect inorganic constituents. The precursor ion is the metal-ligand complex and the product ion is the metal cation. Identification is confirmed via isotopic ratios. A controlled shooting study using 1-3 shots from a 9mm and 0.38 revolver resulted in consistent detection of lead and EC down to a single shot discharge. Barium, calcium, and iron were also detected. The detection of antimony requires of use of tartaric acid, a multi-dentate ligand. [ABSTRACT FROM AUTHOR]

Forensic ballistics a core field of forensic science, and focuses on locating the point and time of firing as well as matching the bullet to a specific firearm. The paper proposes a model for legally authorized firearms and bullets that enables instant determination of location and time of firing. This facilitates the identification of the bullet to the questioned firearm, eliminating the conduction of conventional methods of examination. This is achieved by the implementation of an in-built positioning system in the firearm utilizing a Global Positioning System (GPS) together with a means of identification of the projectile to the suspected firearm, employing Radio-Frequency Identification (RFID). A protective aspect of reducing the crime rate and more accurate method of analysing and examining the fired bullets from suspected firearms, this technique if used can also strengthen the judgements taken by law enforcement agencies. [ABSTRACT FROM AUTHOR]

The insufficient recognition of injuries by the BB-gun (regarded as toys for children) has led to its increasing misuse without permission, which has caused many public safety issues. Aiming to enhance the understanding of the injuries by the BB-gun, the experimental and numerical study of BB-Gun pellet penetrating "cowhide + gelatine" composite target was comprehensively carried out. It was confirmed from the experiment that BB-Gun is capable of inflicting severe or fatal wounds to important organs, and perforating the skin or not could be employed to evaluate the safety of BB-guns. Moreover, three forms of ballistic limit (including: velocity, kinetic energy and specific kinetic energy) of typical BB were calculated and analyzed by reasonably validated numerical simulation method. Additionally, a formulation was acquired by dimensional analysis based on the simulation results and was verified to accurately predict the ballistic limit velocity of BB with different mechanical properties. The method may help to improve the understanding on the minimal velocity needed to perforate skin and may be advised as the determination of the safety of BB-gun. [ABSTRACT FROM AUTHOR]

The present paper aims to assess the risk of rib fractures caused by any rigid less-lethal kinetic energy projectiles. To that end, a coupled experimental and numerical approach is proposed to relate ballistic experiments with the risk of blunt trauma. A polymer gel block is employed as ballistic testing medium to interpret ballistic impacts through the measurement of the dynamic gel wall displacement. Moreover, a biofidelic 50th percentile human torso finite element model created in the code Hypermesh (Altair HyperWorks ©) is used to replicate experiments and real world accidents. Then, the probability curve of rib fractures is a function of the viscous criterion and derives from a study on human cadaver mid-sternum available in the literature. Twelve impact conditions of rigid projectiles are applied to a SEBS gel block and are replicated on the human torso model mid-sternum. A statistical analysis is performed by virtue of a Spearman's correlation matrix in order to identify relations between experimental measurements and the viscous criterion evaluated numerically. The determination of both statistical significances and correlation coefficients results in several strong correlations between experimental measurements and the viscous criterion evaluated numerically. These relations imply the establishment of transfer functions between experimental metrics on the gel block (the maximum gel wall displacement and a gel wall displacement - rate of displacement based metric) and the probability of rib fractures. Finally, these correlations constitute a primary and an up-and-coming predicting tool for the risk of rib fractures. [ABSTRACT FROM AUTHOR]

Law enforcement agencies routinely sample for gunshot residue (GSR) by bulk techniques and often submit swabs taken from other surfaces besides the hands of the suspect shooter. This study aims to establish the prevalence of antimony, barium, and lead on normally handled automobile surfaces by graphite furnace atomic absorption analysis. No positives were determined on 50 sampled automobile surfaces above cutoff (positive) from background levels. Transfers of GSR particles from shooter hands to automobile surfaces were found to potentially allow for positive GSR determinations, but such transfers seem to be dependent on the shooting conditions and length of GSR exposure. We determined that our bulk analysis method yields an overall 87.94 ± 5.52% extraction efficiency from cotton swabs, while the LOQ determinations strengthening the fact that bulk analysis methods are valid and valuable tools for GSR investigations. [ABSTRACT FROM AUTHOR]

The Glock company's newest generation of pistols (G42/43, Gen5) is equipped with so-called "Glock Marksman Barrels" (GMB). These barrels feature an enhanced polygonal profile with right-hand twist and a small rifled profile on either side of the main polygonal field impression (Hernandez et al., 2016). Up until now, using the usual methods of comparison (automatic ballistic identification systems, ABIS and comparison microscope) it was difficult to assign bullets fired from a polygonal barrel to their origin with a high evidentiary value (Murdock et al., 1990) [5] (Northcutt, 2010). In this study, test shots from 18 Glock Gen5 pistols (9 Glock 17 pistols and 9 Glock 19 pistols) were compared to examine their differentiability. In addition, a Gen5 Glock 17 pistol was used to shoot 500 cartridges to determine to what degree the first projectile could be matched with the 500th (Zhang and Luo, 2018) [10]. This study was able to demonstrate that the new "Glock Marksman Barrel" (GMB) leaves marks of sufficient quality on projectiles to make high evidentiary value assignments of those projectiles to an individual firearm, both by using the comparison microscope as well as with an ABIS (Evofinder®). Further, it was possible to assign the cartridge casings to an individual pristine firearm. [ABSTRACT FROM AUTHOR]

From time to time, severe or fatal injuries caused by small caliber air rifle projectiles are seen. In forensic sciences, the theoretical wounding potential of these weapons and projectiles is widely known. Usually, shots against the skull were reported and, in these cases, penetrating the eyes or thin bone layers of the temporal region. Amongst a huge number of different projectiles available for air guns, sub-caliber 4.4-mm (.173) caliber steel ball projectiles were used in an unusual suicide case. This case led to fundamental questions concerning wound ballistics. An 82-year-old man shot once against his right temporal region and twice into his mouth with a 4.5-mm (.177) caliber air rifle. Because of the exceptionally deep penetration of the base of the skull and the use of spherical-shaped sub-caliber air rifle projectiles, terminal ballistic features were analyzed and compared to results published in forensic literature. Test shots using the same weapon and similar projectiles were fired into ballistic gelatin to measure and calculate basic wound ballistic variables of cal. 4.4-mm (.173) steel balls. In comparison, further test shots with cal. 4.5-mm (.177) steel balls BB (ball bearing), flat-headed and pointed air rifle pellets ("diabolos") were carried out. The theoretical penetration depth in solid bone was calculated with 36.4 mm, and test shots in gelatin from hard contact produced an on-average wound track of 120 mm underlining the potential wounding effect. Furthermore, spherical projectiles could roll back and forth within the barrel, and an air cushion between projectile and breechblock can reduce muzzle velocity by more than half, explaining the retained missile in the temporal region. [ABSTRACT FROM AUTHOR]

Synthetic models, also called "surrogates", are commonly used in wound ballistics in order to simulate human tissues. Despite several surrogates are worldwide accepted and used; some of them have not been yet fully validated and their limits for forensic reconstructions have not been deeply investigated yet. In this work we present a homicide/suicide case involving three gunshots to the head with bullets retained in the skull or beneath the scalp. Reconstruction of these cases was performed preparing three individual synthetic head models based on post-mortem computed tomography (PMCT) measurements. Ballistic soap, polyurethane plates and 10% ballistic gelatine at 4°C were used as simulants in individually adapted thickness. Ballistic tests were performed using the questioned firearm and ammunition type. The damages on the synthetic models have been compared to the findings in PMCT and autopsy of the victims. Although the results highlighted general similarities in terms of injury characteristics, some of the experimental shots overpenetrated. Furthermore, the bullets recovered in the synthetic models did not show the same quality of deformations as the questioned bullets. This lack of bullet deformation in the synthetic models might be mainly attributed to the physical difference between real bones and polyurethane surrogate. [ABSTRACT FROM AUTHOR]

A bystander claimed to have been shot by a police officer, and CT scans were used to match qualitative and quantitative aspects of the unremoved bullet with police issued 9 mm Luger ammunition. CT scan methodology proved a valid approach for the measurement of bullets based on calculated measurement capability and correlation with "gold standard" physical measurement by vernier caliper. Measurements regarding length and base diameter, as well as length/diameter ratio, were insufficient to unambiguously identify a specific caliber, or a bullet of specific mass within a caliber class. It was, however, possible to exclude a bullet of specific design and mass with well‐characterized precision and accuracy values under selected CT scan conditions. A 9 mm Luger bullet (115 gr FMJ RN) was excluded from involvement in a shooting based on qualitative bullet shape combined with length, base, and ratio measurements of the bullet in‐situ for the victim. [ABSTRACT FROM AUTHOR]

Solid-phase microextraction (SPME) has been established as a very powerful alternative to traditional extraction methods since its introduction in the early 1990s. The heart of the SPME device is an expensive thin and very delicate fused-silica fiber, coated with a thin polymer film. When extracted, the fiber may bend and break. Due to the fragility of the SPME fiber, a fiber protector device is proposed. The protector is easily assembled on the SPME device and can easily be removed by unscrewing for sampling to the injector. The SPME with the fiber protector was tested by headspace-SPME (HS-SPME) gasoline and diesel fuel vapor analyses. The results of the extractions with the SPME protector were compared with the results of the extractions by SPME without the protector. An enhancement to the lighter hydrocarbons was observed in the results with the protector but the method sensitivity was not altered. The SPME protector was easily cleaned from contaminant residues by ethyl acetate washings. The protector can be used for years and the fibers remain intact for hundreds of samplings. [ABSTRACT FROM AUTHOR]

Trajectory deflections of 5.56 NATO and 7.62×39mm rifle bullets, fired through 7.5, 15 and 22.5cm of gelatine, were studied. The magnitude of the deflections from the bullets' original trajectories after perforation are related to the length and the profile of the (wound) channels through gelatine. After 7.5cm of penetration depth, deflection was less than 1°. With the longer channel lengths, bullet instability set in and subsequently, deflection was much larger. Deflection was highest with fragmented 5.56 NATO bullets after perforating 22.5cm of gelatine. The data from this study can be used to assess the degree of bullet deflection in trajectory reconstructions after incidents where human bodies were perforated with rifle bullets of the respective calibres and cartridge types. [ABSTRACT FROM AUTHOR]

Comparing the marks left on questioned bullets to those left on reference bullets is the main aim of a firearm identification expertise. Thus, producing reference bullets with a questioned firearm is an essential step. Different kinds of system have been developed to safely recover bullets fired from questioned firearms. However, the performance of each system and its impact on traces left on the bullets have not been addressed. Three bullet recovery systems - a horizontal water tank, a cotton tube and a recently designed fleece - were used to fire seven types of ammunition of various type, shape and casing. The bullets were then described and images of their surface were acquired with an automatic system to study the impact of each system on the bullets. The water tank is the more efficient system in terms of quality of the marks. However, it cannot be used to fire every type of ammunition. Some of them, such those used by law enforcement, tend to be damaged with this system. A way to mitigate the problem is to use the cotton or the fleece-based systems, the latter being more universal. It requires a cleaning step to remove all the fibres from the surface of the bullet, but the marks left by the weapon are still of interest. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Fingermark development techniques for brass cartridge cases/plates were evaluated. • The sequence CA + GB + fluorescent dye (BY40 or Ardrox) presented the best results. • The application of the entire sequence of developers is strongly recommended. • The gaseous blowback is the main firing effect on the deterioration of fingermarks. • Handling cartridges when loading a gun has a significant influence on the fingermarks. Abstract A study was undertaken wherein different fingermark developers were evaluated for the recovery of fingermarks from brass cartridge cases, besides the evaluation of factors such as firing effects and surface characterization of the cases. The latent fingermarks on α-brass plates, fired and unfired cartridge cases were deposited and aged for 1–14 days before development with different developers. In order to mimic the fired cartridge case conditions, the brass plates were heated and examined at room temperature (RT), at 63 and at 200 °C. The sequential treatment with cyanoacrylate, gun blue and fluorescent dye has been found to be the best among other developers for the recovery of latent fingermarks on brass surfaces including fired and unfired cartridge cases. Cartridge cases and other brass surfaces were also analyzed by surface characterization methods, including X-ray diffraction, scanning electronic microscopy, energy dispersive X-ray spectroscopy and metallographic examination. The tested surfaces correspond to α-phase brass Cu 0.7 Zn 0.3 composition and have shown different surface morphologies (such as grain structure) and different levels of oxidation, even for cartridge cases obtained from the same batch. Due to this, the effectiveness of a given reagent for a specific brass surface is uncertain. Therefore, the application of the entire tested sequence of developers is strongly recommended. Further, the effects of firing on fingermarks on cartridge cases were examined, and the results indicated that the blowback of hot gases through the looseness between cartridge case and chamber wall of the firearm is the main cause responsible for deterioration of fingermarks during firing. Despite the recognized damage caused to fingermarks by the firing effects, good quality fingermarks were recovered from fired cartridge cases in which full fingermarks were intentionally deposited prior to firing. This indicates that the handling of the cartridges before and during the loading of the gun may have a strong influence on the quantity and quality of fingermarks, and that the firing itself is not the main responsible factor for the absence or low quality of fingermarks, as frequently reported in fired cartridge cases studies. [ABSTRACT FROM AUTHOR]

Advanced image processing algorithms can support the forensic analyst to make tasks like detection, pattern comparison or identification more objective. In the case of the gunshot residue (GSR) analysis, the automatic detection of potential GSR samples can support the task of evidence collection or analysis of residue needed e.g. for a muzzle-to-target firing distance estimation. In this paper we investigate the application of a hyperspectral camera and two well-known Machine Learning algorithms to automatically indicate the potential presence of GSR samples in a scene containing cloth fabrics. For this study we have created and annotated a hyperspectral image dataset consisting of GSR samples present on multiple fabric types. The GSR samples were obtained using two types of ammunition, discharged from two shooting distances. We have investigated two detection scenarios: an unsupervised anomaly detection (with the RX detector) and a supervised pixel classification (with the SVM classifier). Our results show that an accurate detection is possible in both cases. We also note that in this setting the anomaly detection approach usually requires an image normalisation, while the classifier does not require a fabric-specific information. As an addition, we show that the hyperspectral imaging generally outperforms the RGB imaging in terms of GSR detection accuracy. While the actual verification on presence of GSR on the scene requires an analyst and secondary identification methods, the hyperspectral camera with image processing algorithms can be a valuable tool supporting the evidence collection and analysis. [ABSTRACT FROM AUTHOR]

When a firearm is discharged, a gaseous cloud containing characteristic particles of gunshot residue (GSR) are released forward and behind at high speed, depositing on clothing, hands, face and hair, as well as being inhaled and therefore retained in the nostrils of the person who fired the weapon. GSRs have characteristic sizes and morphologies and consist of a combination of lead, antimony and barium, as well as other elements. Scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDS) is a widely accepted technique for the analysis of these residues; however, little has been reported on samples taken from the nostrils of the suspect that discharged the shot. The analysis of residues found on hands has been more frequent. This article presents a device (Nasal Stub) developed by us for the non-invasive collection of GSR particles from the nostrils and a platform also developed by us to contain these devices that is compatible with SEM-EDS. To evaluate the effectiveness of our Nasal Stub to collect GSR particles from nose hairs, four types of firearms of different calibers were utilized. Nasal samples were collected at 0, 2, 4, 6, 8, and 20h after firing. The results show that the nasal device was able to recover GSR particles from nose hairs for all the weapons used, even, in some cases, over 20h after firing. It was concluded that Nasal Stub and its methodology proposed for the analysis of nasal GSR from nose hairs by SEM-EDS was effective and that it can complement other traditional analyses of GSR particles, increasing the amount of evidentiary support for the forensic analysis presented in a tribunal or court. [ABSTRACT FROM AUTHOR]

The Association of Firearm and Toolmark Examiners recommends a minimum of two test fires be performed when an unknown firearm is submitted to a laboratory prior to doing a comparison with a cartridge case collected from a crime scene. Limited research has been performed to determine how many test fires are necessary to be representative of the match distribution of a firearm. Various makes and models of firearms comprising five calibers were tested using a hybrid equivalence test to determine how many cartridge cases were required to represent the match distribution of an unknown firearm based on both breech face and firing pin correlation scores from an IBIS® HeritageTM System. The same general trend was observed for each caliber of firearm where the equivalence percentage increased from 10 to 30 cartridge cases. Overall, 15 cartridge cases are sufficient for above an 80% probability of representing the full match distribution for an unknown firearm. To approach full equivalence, 25 cartridge cases are enough because 30 cartridge cases were not found to be significantly higher in equivalence percentage for any caliber of firearm tested. [ABSTRACT FROM AUTHOR]

Trajectory deflections of pistol bullets from four different firearms, fired through soft tissue simulants under two different incidence and exit angles were studied. The data from this study can be used in reconstructions of shooting incidents where human soft tissues (not bones) were perforated with pistol bullets and assumptions must be made about bullet deflection in order to correctly reconstruct trajectories. The results demonstrate that deflection was influenced by the length of the "wound channel" through the simulants. In short, deflection was small to virtually absent with 5 and 10cm channel lengths. With channel lengths of 15, 20 and 25cm, there was a clear increase in deflection and/or a more erratic deflection behaviour with most shots. The data also suggest an influence of the angle of incidence and/or exit on both the direction and the magnitude of the deflection. [ABSTRACT FROM AUTHOR]

This novel investigation focused on studying the transfer of explosive residues (TNT, HMTD, PETN, ANFO, dynamite, black powder, NH 4 NO 3 , KNO 3 , NaClO 3 ) in ten consecutive fingerprints to two different surfaces – cotton fabric and polycarbonate plastic – by using multispectral imaging (MSI). Imaging was performed employing a reflex camera in a purpose-built photo studio. Images were processed in MATLAB to select the most discriminating frame – the one that provided the sharpest contrast between the explosive and the material in the red-green-blue (RGB) visible region. The amount of explosive residues transferred in each fingerprint was determined as the number of pixels containing explosive particles. First, the pattern of PETN transfer by ten different persons in successive fingerprints was studied. No significant differences in the pattern of transfer of PETN between subjects were observed, which was also confirmed by multivariate analysis of variance (MANOVA). Then, the transfer of traces of the nine above explosives in ten consecutive fingerprints to cotton fabric and polycarbonate plastic was investigated. The obtained results demonstrated that the amount of explosive residues deposited on successive fingerprints tended to undergo a power or exponential decrease, with the exception of inorganic salts (NH 4 NO 3 , KNO 3 , NaClO 3 ) and ANFO (consists of 90% NH 4 NO 3 ). [ABSTRACT FROM AUTHOR]

Post-mortem imaging has become more frequently used in forensic procedures, notably in a ballistic context. Despite many advances in this field, the interpretation of computed tomography (CT) can be a very complex matter. Our case illustrates the difficulties of interpretation after quasi-tangential cranial ballistic impact and keyhole wounds. These wounds are difficult to visualize on CT and are among the factors complicating the precise determination of ballistics. These sources of error remind us that CT findings must be interpreted in close comparison with autopsy findings. [ABSTRACT FROM AUTHOR]

A novel feature-based method, which is scale invariant feature transform (SIFT) and RANdom SAmple Consensus (RANSAC) integration algorithm, is introduced to promote the automated identification of the breech face impression, the most common mark left on the cartridge used for firearm evidence. SIFT algorithm is employed to extract the local extrema from examined impression as keypoints representing its invariant features, and to build the feature descriptor for each keypoint based on its local gradients in neighborhood. RANSAC is used to improve the matching performance among these keypoints and feature descriptors. With hypothesize-and-verify methods, RANSAC is able to construct the best model fitting initial matching pairs of keypoints and to guarantee the robust comparison result. Validation tests using 40 cartridge cases fired from pistols with 10 consecutively manufactured slides yielded a clear separation result, which strongly supports the effectiveness of the ensemble algorithm of SIFT and RANSAC. This application indicates the practical feasibility of feature-based algorithm and image processing technique in forensic science. [ABSTRACT FROM AUTHOR]

On 18 July 1944, a convoy of German trucks was ambushed by the French Resistance near the village of Thorame-Haute in SE France. According to reports by French witnesses, the first German truck exploded. After a brief firefight, the Resistance pulled out without casualties, claiming that 58 Germans had been killed in the attack, including a high-ranking officer. The current project used witness interviews, archives materials, and metal detecting to validate the descriptions of the ambush. The project confirmed that at least nine German soldiers had been killed in the attack. The metal detecting survey recovered numerous small artefacts whose condition and dispersal indicated that a violent explosion had indeed occurred and had probably been preceded or followed by a fire. A grouping of fired cartridge casings was found in the former Resistance positions. The project was able to confirm the French accounts apart from the casualty figures. [ABSTRACT FROM AUTHOR]

This paper describes a new witness material for quantifying the back face deformation (BFD) resulting from high rate impact of ballistic protective equipment. Accurate BFD quantification is critical for the assessment and certification of personal protective equipment, such as body armor and helmets, and ballistic evaluation. A common witness material is ballistic clay, specifically, Roma Plastilina No. 1 (RP1). RP1 must be heated to nearly 38°C to pass calibration, and used within a limited time frame to remain in calibration. RP1 also exhibits lot-to-lot variability and is sensitive to time, temperature, and handling procedures, which limits the BFD accuracy and reproducibility. A new silicone composite backing material (SCBM) was developed and tested side-by-side with heated RP1 using quasi-static indentation and compression, low velocity impact, spherical projectile penetration, and both soft and hard armor ballistic BFD measurements to compare their response over a broad range of strain rates and temperatures. The results demonstrate that SCBM mimics the heated RP1 response at room temperature and exhibits minimal temperature sensitivity. With additional optimization of the composition and processing, SCBM could be a drop-in replacement for RP1 that is used at room temperature during BFD quantification with minimal changes to the current RP1 handling protocols and infrastructure. It is anticipated that removing the heating requirement, and temperature-dependence, associated with RP1 will reduce test variability, simplify testing logistics, and enhance test range productivity. [ABSTRACT FROM AUTHOR]

Military combat helmets protect the wearer from a variety of battlefield threats, including projectiles. Helmet back-face deformation (BFD) is the result of the helmet defeating a projectile and deforming inward. Back-face deformation can result in localized blunt impacts to the head. A method was developed to investigate skull injury due to BFD behind-armor blunt trauma. A representative impactor was designed from the BFD profiles of modern combat helmets subjected to ballistic impacts. Three post-mortem human subject head specimens were each impacted using the representative impactor at three anatomical regions (frontal bone, right/left temporo-parietal regions) using a pneumatic projectile launcher. Thirty-six impacts were conducted at energy levels between 5 J and 25 J. Fractures were detected in two specimens. Two of the specimens experienced temporo-parietal fractures while the third specimen experienced no fractures. Biomechanical metrics, including impactor acceleration, were obtained for all tests. The work presented herein describes initial research utilizing a test method enabling the collection of dynamic exposure and biomechanical response data for the skull at the BFD-head interface. [ABSTRACT FROM AUTHOR]

Gun violence is a global phenomenon with regional variation in frequency and severity. Handguns are often used in violent deaths such as suicides and homicides. Hence, ballistic trauma is a critical subject of forensic investigations. Trauma patterns are fundamental evidence for the reconstruction of the incident and for the determination of the manner of death. This study investigated the differences in trauma patterns with a series of experiments using six different calibers (.22 LR, .38 Special, .380 ACP, 9×19mm, .40 S&W, and .45 ACP) and four different bullet types. Synbone® spheres (polyurethane bone proxies) were used for close range 30cm simulated executions. The polyurethane spheres constitute an excellent proxy for human crania at the macroscopic level as suggested by other studies. The results showed that the radius of the entrance wound is positively correlated (Pearson's correlation coefficient R=0.846, p<0.05) with the caliber dimension. As muzzle velocity increased, endocranial beveling increased. Bullet weight, conversely, does not seem to have an effect on the size of the endocranial beveling present in Synbone® spheres. The ballistic experiments exhibited similarities in entrance wound morphology; radial and concentric fracture patterns, hydraulic burst effect, circumferential delamination, and endocranial beveling with that of documented forensic cases with corresponding caliber shot. Synbone spheres seem appropriate for ballistic simulations of cranial injuries; yet, more research is needed to verify these observations. [ABSTRACT FROM AUTHOR]

The aim of this work was to simulate an overmatch ballistic event against a head wearing a helmet. The experiments were designed to understand how layers of bone (or synthetic bone), synthetic skin and currently used helmet materials influence the behaviour of full metal jacket mild steel core (FMJ MSC) 7.62 × 39 mm bullets, impacting on targets with a mean velocity of 650 m/s. Bullet behaviour within 10% (by mass) gelatine blocks was assessed by measurements made of the temporary cavity within the blocks using high-speed video and of the permanent cavity by dissecting blocks post firing. While ANOVA did not find significant difference at the 0.05 level in the mean values of most of the measurements, there was a significant difference in neck length within the gelatine blocks. The addition of material layers did produce greater variability in the temporary cavity measurements under some of the conditions. One of the synthetic bone polymers with a synthetic skin layer produced similar results within the gelatine blocks to the horse scapulae (with residual tissue) and may be suitable for future ballistic experiments. [ABSTRACT FROM AUTHOR]

Introduction. For homemade firearm, as well as for blank pistol, tear gas gun or cap pistol, that are adapted to use as firearm, there is a commonly used term - zip gun. Presented zip gun is one of the simplest crude homemade firearms that was found among reviewed articles. Case report. We present a case where a young man committed suicide by using a very simple, crude zip gun. The iron tube was used as a barrel. At one end of the iron tube a hunting cartridge was inserted. That end of the tube was closed by iron cylinder with a screw breaching through the center. The decedent was holding the metal tube i.e. the barrel in left hand. He was holding a hammer with his right hand and trying to hit the head of the screw which was, in this case, used as a firing pin. Conclusion. Authors would like to emphasize the importance of thorough investigation and detailed documentation of the crime scene. Particular attention is needed in cases were unusual metal or other parts can be found at the scene from witch a crude homemade gun can be made. We also emphasize that, because of the low power of these kind of firearms and possibility of surviving the shot, if the vital structures are not damaged, an urgent and adequate medical intervention could save the injured persons life. [ABSTRACT FROM AUTHOR]

We explore the impact of information from ballistics imaging hit reports on the investigation into violent crimes. Ballistics imaging hits link two crimes involving the same firearm by forensically matching tool marks on the fired bullets or cartridge cases. Interview data collected from detectives who received a hit report were used to explore the relationship between the presence of a hit report and outcomes in 65 gun-related violent crime investigations in nine U.S. police agencies. Findings indicate hit reports rarely contribute to identification, arrest, charging, or sentencing of suspects, because of delays in producing hit reports. On average, hit reports were completed 181.4 days after the focal crime. This delay forces investigations to proceed without the benefit of information from ballistics analysis. Additionally, hit reports rarely contained detailed information that was immediately useful to investigators. Instead, hit reports required additional research by the investigator to unlock useful information. [ABSTRACT FROM AUTHOR]

TASER weapons, classified as Conducted Energy Weapons (CEWs) are used by law enforcement as electrical, non-lethal weapons. A CEW's long distance method of deployment launches two barbed probes that embed into the target, before electricity is cycled from one probe to the other. The resulting muscle contractions help incapacitate the intended target. Currently, there is no research on the accuracy of variability of CEW probe spread in determining the distance of the shooter. Thus, in this study, a method of distance determination for TASER models X26P, X2, and TASER 7 was established to help estimate the relative locations of individuals during crime scene reconstruction. Each of four probe cartridge types were launched for six repetitions towards vertical cardboard targets from three different distances (n = 72). The probe spread on the targets was measured for each cartridge and plotted against CEW-To-Target (CTT) distance. Linear regression trendlines and standard deviations were generated for each cartridge type. Results demonstrated probe spread distances to be proportional to probe launch angles, and greater CTT distances resulted in greater standard deviation. Standard error of the estimate was calculated for all four linear regression equations and their ability to predict CTT distance when given probe spread measurements. The mean standard error values appeared acceptable for the X2 (0.460 m), TASER 7 CQ (0.273 m), and X26P (0.322 m) CEW models, while the mean error calculated for the TASER 7 Standoff model (0.846 m) was considerably greater. We expect our findings will help establish a reliable method of distance determination for CEWs, and perhaps with a larger sample size, more thoroughly examine the accuracy of the linear regression equations. CEW distance determination has the potential to provide support in contextualizing crime scene reconstruction with further research. By providing distance estimations alongside a standardized guide of error allowance, it would be possible to induce how far apart individuals were at the time a CEW was fired, within the calculated window of deviation, and in a statistical degree of confidence. [ABSTRACT FROM AUTHOR]

Purpose: Today, synthetic models have all but replaced animal and corpse models in examining damage to soft-tissues and skeletal structures by ballistic trauma. As, however, non-solid organs such as the lungs, have not been able to be replaced by a fully synthetic model we attempted to create such a model.Material and Methods: 20% ordnance gelatine was frothed with a household mixer and cooled to stable foam. Several of these foam blocks were then stuck together with liquid gelatine and placed between 10% gelatine blocks. As controls, we embedded pig lungs in gelatine and compared the wound channels seen in computed tomography created upon shooting with 9mm Luger.Results: The fully synthetic models displayed radiological and physical densities comparable to real lungs. The wound profile characteristics of the fully synthetic lung models were very similar to the semisynthetic swine-gelatine models regarding the permanent wound cavity. Furthermore, in both semi- and fully synthetic models we detected a ring surrounding the permanent wound channel, most likely representing the remnants of the temporary wound cavity.Conclusion: Our results indicate that this fully synthetic lung model is a viable substitute for ballistic experiments on lungs. We believe that further research on the temporary wound channel in lungs is possible with this model in order to provide more insight into the effect of ballistic trauma to the lungs not seen otherwise. [ABSTRACT FROM AUTHOR]

The presence of "chipping" or "flaking" around the edges of gunshot entry wounds has been described among the characteristics of gunshot wounds in bone. In this study, the real frequency of such a peculiar feature was investigated. The presence of "chipping" was assessed on 22 gunshot wounds fired at a near-contact range on bovine ribs with 9-mm bullets. As controls, five samples were shot with a 3 cm range, and five from 40 cm. In 77% of cases shot at near-contact range, a detachment of small fragments of the upper layers of bone was detected, mainly with a circumferential disposition, whereas this feature was lacking in control samples. The study demonstrated the frequency of "chipping" and that it may probably be due to a combined ballistic effect of impact of the bullet itself and expansion of gases. It may be thus considered indicative of close-range shots. [ABSTRACT FROM AUTHOR]

The defendant, the driver of the questioned car, allegedly extended his right arm over the passenger seat and fired a single shot from a 380 pistol out the passenger window with the pistol's breech within the car. A simulation of this shooting scenario using the same model car, but different year, was conducted to quantitate gunshot residue (GSR) contamination of interior surfaces within the car. The test car's dash and headliner/window frame above the pistol had the heaviest GSR contamination. The dash GSR from airborne deposition documents a firearm discharge within the vehicle. Transfer from GSR-contaminated hands or clothing to the dash is unlikely. The heavy GSR contamination of the headliner/window frame above the pistol likely documents the window from which the pistol was fired, but additional experiments are needed to verify. [ABSTRACT FROM AUTHOR]

The current study aims to investigate the effectiveness of two different designs of helmet interior cushion, (Helmet 1: strap-netting; Helmet 2: Oregon Aero foam-padding), and the effect of the impact directions on the helmeted head during ballistic impact. Series of ballistic impact simulations (frontal, lateral, rear, and top) of a full-metal-jacketed bullet were performed on a validated finite element head model equipped with the two helmets, to assess the severity of head injuries sustained in ballistic impacts using both head kinematics and biomechanical metrics. Benchmarking with experimental ventricular and intracranial pressures showed that there is good agreement between the simulations and experiments. In terms of extracranial injuries, top impact had the highest skull stress, still without fracturing the skull. In regard to intracranial injuries, both the lateral and rear impacts generally gave the highest principal strains as well as highest shear strains, which exceed the injury thresholds. Off-cushion impacts were found to be at higher risk of intracranial injuries. The study also showed that the Oregon Aero foam pads helped to reduce impact forces. It also suggested that more padding inserts of smaller size may offer better protection. This provides some insights on future's helmet design against ballistic threats. [ABSTRACT FROM AUTHOR]

This study investigated the use of laser-induced breakdown spectroscopy (LIBS) and scanning electron microscopy energy dispersive X-ray spectroscopy (SEM-EDX) as means of characterizing gunshot residue (GSR) originating from commercially available lead-free rounds. Data from two experiments are presented in this work. One experiment focused on identifying prominent analytical markers present in lead-free GSR by LIBS while the other applied SEM-EDX to determine the degree of evidence preservation after LIBS analysis. Samples of GSR were collected via tape-lift method from the hands of volunteer shooters and instrumental analyses were conducted in triplicate. As a result, the lead-free ammunition analyzed in this work generated GSRs comprising primarily Ba, Al, Si, and/or K. Trace amounts of Ti, Fe, and S were also apparent in some compositions. Through SEM-EDX analysis, a spheroidal geometry consistent with traditional lead-containing GSR was observed. Additionally, it was determined that evidence is preserved after LIBS analysis which supports the implementation of LIBS as a rapid preliminary screening method followed by confirmatory testing via SEM-EDX on the preserved evidence. [ABSTRACT FROM AUTHOR]

Complications arise in the analysis of gunshot wounds to the maxillofacial region, when neither the projectile nor the gun is found at the crime scene. We simulated 5- and 15-cm firing distances at a human mandible to investigate the external morphology of entrance wounds based on fire range. The ammunition models, .40-caliber S&W, .380-caliber, and 9 × 19-mm Luger, were constructed with free-form NURBS surfaces. In a dynamic simulation, projectiles were fired against mandibular body 3D model at 5 and 15 cm. All entrance wounds presented oval aspect. Maximum diameter and von Mises stress values were 16.5 mm and 50.8 MPa, both for .40-caliber S&W fired at 5 cm. The maximum energy loss was 138.4 J for .40 S&W fired at 15 cm. In conclusion, the mandible was most affected by .40-caliber S&W and morphological differences were observable in holes caused by different incoming projectile calibers fired at different distances. [ABSTRACT FROM AUTHOR]

Simultaneous determination of nitrate and nitrite in gunshot residue has been conducted by capillary electrophoresis using an acidic run buffer ( pH 3.5). In previously developed capillary electrophoretic methods, alkaline pH separation buffers were used where nitrite and nitrate possess similar electrophoretic mobility. In this study, the electroosmotic flow has been reversed by using low pH running buffer without any additives. As a result of reversing the electroosmotic flow, very fast analysis has been actualized, well-defined and separated ion peaks emerge in less than 4 min. Besides, the limit of detection was improved by employing large volume sample stacking. Limit of detection values were 6.7 and 4.3 μM for nitrate and nitrite, respectively. In traditional procedure, mechanical agitation is employed for extraction, while in this work the extraction efficiency of ultrasound mixing for 30 min was found sufficient. The proposed method was successfully applied to authentic gunshot residue samples. [ABSTRACT FROM AUTHOR]

The influence of the distance to the top and bottom of a gelatine block and to bullet tracks from previously fired shots on a bullet's trajectory, when passing through ballistic gelatine, was studied. No significant difference in deflection was found when trajectories of 9mm Luger bullets, fired at a 3.5cm distance to the top and bottom of a gelatine block and to bullet tracks from previously fired shots, were compared to trajectories of bullets fired 7cm or more away from any of the aforementioned aspects. A surprisingly consistent 6.5° absolute deflection angle was found when these bullets passed through 22.5 to 23.5cm of ballistic gelatine. The projection angle, determined by the direction of the deflection, appeared to be random. The consistent absolute angle, in combination with the random projection angle, resulted in a cone-like deflection pattern. [ABSTRACT FROM AUTHOR]