Bullet Wipe Research Articles

Histopathological detection of entry and exit holes in human skin wounds caused by firearms

The judiciary needs forensic medicine to determine the difference between an entry hole and an exit hole in human skin caused by firearms for civilian use. This important information would be most useful if a practical and accurate method could be done with low-cost and minimal technological resources. Both macroscopic and microscopic analyses were performed on skin lesions caused by firearm projectiles, to establish histological features of 14 entry holes and 14 exit holes. Microscopically, in the abrasion area macroscopically observed, there were signs of burns (sub-epidermal cracks and keratinocyte necrosis) in the entrance holes in all cases. These signs were not found in three exit holes which showed an abrasion collar, nor in other exit holes. Some other microscopic features not found in every case were limited either to entry holes, such as cotton fibres, grease deposits, or tattooing in the dermis, or to exit holes, such as adipose tissue, bone or muscle tissue in the dermis. Coagulative necrosis of keratinocytes and sub-epidermal cracks are characteristic of entry holes. Despite the small sample size, it can be safely inferred that this is an important microscopic finding, among others less consistently found, to define an entry hole in questionable cases.

Identifying the source of bullet wipe: a randomised blind trial

To assess the usefulness of scanning electron microscopy and energy dispersive x-ray spectroscopy in matching bullet wipe to the bullet. Bullet wipe can be used to match a bullet type to a crime scene.

The Analysis of Gun‐Cleaning Oil as Long‐Distance Gunshot Residue and Its Implications for Chemical Tags on Bullets

Using a BB gun, it was shown that a gun-cleaning oil (GCO) can be wiped from the barrel by a projectile and carried much longer distances than those usually associated with solid gunshot residue (GSR). Analysis of GCO subsequently deposited on a target was performed using pentane extraction and gas chromatography. (Hoppe's GCO was used here as a model.) When a 0.45 caliber handgun was used, analysis reveals that most of the GCO wiped from the barrel does not survive, owing to the elevated temperatures encountered. However, two components of the GCO, a long-chain fatty acid and its ethyl ester, do survive and can be detected in the bullet wipe. This suggests that GCO may be considered as GSR, uniquely detectable at long distances, and that other chemical compounds could either be added to a GCO or directly to bullets, to serve as identifying chemical tags.

The Utility of Routine Histological Examination of Gunshot Wounds

Determining the range of fire is a crucial part of a forensic examination of gunshot wound victims. Traditionally, this has been accomplished by noting the gross appearance of soot or powder around the wound. This study was undertaken to determine the utility of routine histological examination of gunshot wounds as related to range-of-fire determination. A prospective study was performed, and a total of 69 gunshot wounds were examined both macroscopically and microscopically. Of the 45 entrance wounds examined, there was 100% concordance between macroscopic and microscopic analysis for the close-range wounds and 67% concordance for the distant wounds, with 33% of these wounds showing no evidence of soot or powder grossly but where residue was seen microscopically. In addition, 21% of the exit wounds examined showed microscopic evidence of soot/powder residues when none were visible macroscopically. As described in previous studies, it can be assumed that the bullet itself can deposit small residues along the wound track (bullet wipe) that can be seen microscopically and is unrelated to the range of fire. Therefore, the authors conclude there is no utility in the routine histological examination of gunshot wounds for the determination of range of fire.

Short report of an unusual ballistic trauma

INTRODUCTIONPortable firearms have a relevant medico-legal interest, being a major cause of injury. Bullet entry wounds generally have a particular appearance, including contusion, skin introflection, and simple or excoriated ecchymosis. The skin wound is typically a hole with frayed margins, whose diameter is smaller than that of the bullet. PRESENTATION OF CASEWe report the case of a 19-year-old man with ballistic trauma. Examination of the patient's lesions indicated that the bullet had entered from the left mandibular parasymphysis, creating a small hole without the typical bullet wipe and blackening. Subsequently, the bullet seemed to have fractured the left chin region immediately below the lower alveolar process, and it finally stopped in the submandibular area in the suprahyoid region of the neck. DISCUSSIONThis case is peculiar because the distinctive features of a firearm injury were absent; the lack of bleeding and edema made the case difficult to interpret without additional diagnostic investigations. CONCLUSIONBallistic trauma can manifest in different ways; therefore, internal trauma should be suspected even in the absence of clear external signs. This case report shows how an unusual bullet entry hole can mask quite serious injuries.

Comparison of gunshot injuries caused from Tokarev, Makarov and Glock 19 pistols at firing distances of 1, 3 and 5 cm

Test shots at cloth and at human skin from autopsy material were performed with 7.62 mm Tokarev (TT), 9 mm Makarov (PM) and 9 × 19 mm Glock 19 pistols, using common ammunition. The largest central material defects, with fibre deformation in cotton, the largest burn holes in polyester, and also many fibre defects caused by the perforation of powder, were produced in shots from the TT at all distances. Tears in the cloth were longest in the case of the TT at 1 cm and were present at 3 cm, whereas the shots from the PM and the Glock 19 did not leave tears. There were small tears of the edges of the skin defect from shots fired from the TT at 1 and 3 cm. On cloth-soot deposits at 3 and 5 cm, the radial structures of soot resembled a cobweb (the TT), and radial branching structures (the PM) of soot were seen. Some shots from the PM left four shafts of rays of soot and formed the bullet wipe with four narrow and four wide sections, indicating the form of rifling. In the soot deposit from the Glock 19 with hexagonal rifling, hexagonal or polygonal or petal-like areas were visible. On skin, the soot zones were less distinct. The Glock 19 (at 3 and 5 cm) left a lot of gunpowder particles densely around the cloth and skin defect. The least powder left on the cloth and skin was by the PM. On histological tissue sections, in shots from the TT, a lot of soot and gunpowder residue particles in the epidermis and in both layers of the dermis, and intraepithelial tears and recesses containing soot, were seen. The PM left fine soot and only a few gunpowder particles in the epidermis and in the papillary layer of the dermis. The Glock 19 produced the least soot and a lot of gunpowder particles. The soot and most of the gunpowder particles were present on the tissue sections, which originated from the central area around the skin defect and were detected in the epidermis and in both layers of the dermis. Some tears and recesses in the epidermis were also seen. The further the distance from the centre of skin defect to the periphery, the depth of the penetration of the powder into the skin decreased.

Detection of Gunshot Primer Residue on Bone in an Experimental Setting—An Unexpected Finding*

Pork ribs with intact muscle tissue were used in an experimental attempt to identify bullet wipe on bone at distances from 1 to 6 feet with 0.45 caliber, full metal jacket ammunition. This resulted in the unexpected finding of primer-derived gunshot residue (GSR) deep within the wound tract. Of significance is the fact that the GSR was deposited on the bone, under the periosteum, after the bullet passed through a Ziploc bag and c. 1 inch of muscle tissue. It is also important to note that the GSR persisted on the bone after the periosteum was forcibly removed. The presence of primer-derived GSR on bone provides the potential to differentiate gunshot trauma from blunt trauma when the bone presents an atypical gunshot wound. In this study, the presence of gunshot primer residue at a distance of 6 feet demonstrates the potential for establishing maximum gun-to-target distance for remote shootings.

Pseudo-gunshot wound injury from perforating rib fracture: a cautionary case report

We report a case of a young woman who was found unresponsive in a garbage dumpster beneath the balcony of her 9th floor apartment residence. Initial investigations by the police and coroner raised concerns regarding the circumstances of the death. Initial examination of the body, revealed a single penetrating injury on the chest with a wide abrasion collar--the injury pattern was similar to a gunshot entry wound or a shored exit wound. Autopsy revealed the abraded skin perforation along with major chest injuries with bruising of the chest wall, extensive comminuted rib fractures, and pleural and lung lacerations. These injuries were consistent with the effects of a fatal descent from height. The penetrating injury with the abrasion collar was due to a fractured end of a rib protruding through the skin mimicking a gunshot wound. The involvement of a firearm was further excluded by postmortem radiography (no projectile in situ), detailed external examination of the clothing, and scene investigation revealing that the decedent had descended from a balcony into the dumpster. This case underscores the concept that all round penetrating wounds with abrasion collars are not gunshot injuries.

Comparison of injuries caused by the pistols Tokarev, Makarov and Glock 19 at firing distances of 10, 15 and 25 cm

Firings at cloth targets and at human skin from autopsy material were performed from the pistols 7.62 mm Tokarev (TT), 9 mm Makarov (PM) and 9 × 19 mm Glock 19 with common ammunition. The differences were in the soot deposit pattern, the degree of scorching of the synthetic fibres on the edges of the entrance hole and in the findings of the soot and the gunpowder particles. The results were similar on the cloth and on the skin targets. In the case of the TT and the PM, the soot deposit patterns reminded of a blossom or shafts of rays or fans, or the bullet wipe had four narrow and four wide sections regarding the number of lands and grooves. The TT left a large amount of soot and many gunpowder particles and caused the melting of the synthetic fibres on the edges of the entrance hole, producing a defect of the material 0.1–0.3 cm in diameter and defects of textile fibres around the entrance hole. In the skin the TT caused many intraepithelial tears, folds of the epidermis and recesses of the epidermis containing soot. Firings from the PM and the Glock 19 caused the melting only of the ends of individual synthetic fibres on the edges of the entrance hole. The PM left a large amount of soot and only a few gunpowder particles. The Glock 19 gave the least soot and the greatest number of gunpowder particles and also caused tears and recesses in the epidermis. Only in the case of the Glock 19, hexagonal or polygonal zones were seen in the soot deposit pattern. The differences in the soot pattern were more distinct at the firing distance of 10 cm. By increasing the distance from 10 to 15 cm, the intensity of soot diminished and began to disappear at 25 cm, but remained more visible in the case of the TT. The gunpowder particles could be found in the epidermis and deeper in both layers of the dermis at all distances fired from the TT and the Glock 19. In the case of firings from the PM, at the distance 10 cm some of the gunpowder particles had penetrated into the dermis and most of them were in the upper layer of the dermis. At the firing distance of 15 and 25 cm, the gunpowder particles were only on and in the stratum corneum.

Gunshot injuries as a topic of medicolegal research in the German-speaking countries from the beginning of the 20th century up to the present time

The 100th anniversary of the foundation of the German Society of Legal Medicine is a good opportunity to review its contributions to forensic wound ballistics. The present article gives an overview of the scientific development in this field with special emphasis on work pioneering new developments and findings valid up to the present day, for example the presence of carboxyhemoglobin in the vicinity of the entrance wound as a sign of a contact or close-range shot [A. Paltauf, Wien. Klin. Wochenschr. 3 (1890) 984–991, 1015–1017]; the correct interpretation of the muzzle imprint [A. Werkgartner, Beitr. Gerichtl. Med. 6 (1924) 148–161] and the retrograde ballooning of the bullet entrance region in contact shots [F. Hausbrandt, Dtsch. Z. ges. Gerichtl. Med. 38 (1944) 45–76; H. Elbel, Med. Welt 20 (1958) 343–345]; wound patterns from captive-bolt livestock stunners [H. Czursiedel, Dtsch. Z. ges. Gerichtl. Med. 28 (1937) 132–133]; singeing of synthetic fiber textiles in close-range shots with nitro powder ammunition [S. Berg, Arch. Kriminol. 124 (1959) 5–8,17–22]; the wound ballistic processes on penetration of the bullet and the origin of the abrasion collar [K. Sellier, Beitr. Gerichtl. Med. 25 (1969) 265–270]. More recently medicolegal research in the German-speaking countries covered the following subjects: studies of the dynamic bullet-target interactions in experimental gunshots to simulants and composite body models; use of modern imaging techniques (CT, MRI) in the pre-autopsy diagnosis of lethal gunshot injuries; injuries from blank guns; mechanisms of incapacitation by gunshot injuries; development of improved methods for the evidence of gunshot residues on the firing hand; backspatter from close-range shots; medicolegal contributions in the discrimination of accidental, homicidal and suicidal gunshot injuries.

Ranking the Performance of Aggregates using CEN Test Results

ABSTRACT BS specifications are in common usage in the Irish aggregate industry. After CEN harmonisation, the aggregate abrasion value (AAV) and the polished stone value (PSV) tests will remain unchanged and continue to be used. There will be modifications to the flakiness index, particle density, sand equivalent and methylene blue test procedures. The Micro-Deval (MDE), Los Angeles (LA) abrasion, Sonnenbrand, and Delta ring and ball tests will be new. The aggregate crushing value (ACV), aggregate impact value (AIV) and ten per cent fines value (TFV) will be discontinued. For quarry production, it is likely that the 28 mm stockpile will be replaced by a 31.5 mm stockpile. To rank the performances of aggregates using the CEN tests, four to six test results were used to make comparisons on a statistical basis. Both the parametric Tukey HSD test and the nonparametric Mann-Whitney U test were used in the analyses. Correlations were established between BS and CEN tests for flakiness index. The CEN index is lower. A large correlation (r = 0.90) was established between the LA and the ACV test results. A correlation (r = 0.81) was also established between the MDE and the AAV results. For igneous rocks, water absorption may be an indicator of performance in the MDE test. Stepwise regression procedures were employed to choose a suitable set of predictors for the LA results. Limestone with a higher silica content had a greater resistance to fragmentation. The hematite mineral seemed to have a dominant effect on the outcome of the methylene blue test.

Evaluation of X-ray microfluorescence spectrometry for the elemental analysis of firearm discharge residues

The conventional technique employed to sample Firearm Discharge Residues (FDRs) is by pressing an adhesive coated SEM stub repeatedly over the area of interest. The sample is then analysed by Scanning Electron Microscopy/Energy Dispersive X-ray Spectroscopy (SEM/EDX). While having excellent spatial resolution, the SEM/EDX process lacks elemental sensitivity compared to other techniques such as X-ray fluorescence (XRF), where 100× to 1000× better elemental sensitivity may be achieved. The aim of this preliminary study was to evaluate relatively new technology, X-ray microfluorescence (micro-XRF), as a method of analysing FDRs, to compare the ability of micro-XRF to screen for FDR particles on SEM stubs with that of conventional SEM/EDX analysis, and to evaluate the ability of the micro-XRF to conduct on-target FDR analysis. The micro-XRF utilises a non-destructive method that can rapidly locate and analyse individual FDR particles 10 μm in diameter and larger. This analysis has the advantage that it can produce elemental maps (by X-ray mapping) directly from the target substrates, indicating the distribution of elements across a sample. Different types of ammunition were employed to include various types of primer and bullet compositions. The projectiles and primers were fired onto various target substrates at close-range and the residues analysed by micro-XRF. SEM stubs known to contain FDR particles were also analysed by micro-XRF. The results indicate that micro-XRF can effectively detect and analyse FDR particles that are larger than 10 μm in diameter. With the present instrumental configuration (50 W tube and 100 μm collimator) the micro-XRF cannot replace the SEM/EDX for the analysis of individual FDR particles less than 10 μm in diameter. It was demonstrated that micro-XRF has significant advantages for the on-target analysis of residues resulting from close range discharges (less than 30 cm). Information obtained from the micro-XRF analysis of the bullet wipe area can also give an indication of projectile composition.

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.

An Improved Method of Gunshot Wound Examination

Examination fo gunshot wounds can frequently be obscured by dried blood and other extraneous artifacts. This note describes a method that involves irrigation of the wound with commercial hydrogen peroxide (3% by volume). Which enhances the wound without altering the abrasion ring or powder residues.

Morphology of bullet entrance wounds in palms and plantae (author's transl)

Tests shots with hand weapons of .22, .25, .32, .357, and .45 calibre were made to find out whether bullet entrance wounds in palms and plantae are very different from such wounds in other parts of the body. As far as shots without contact between muzzle and skin were concerned, the following characteristics were noticed: (1) Entrance holes from pistols and revolvers of the same calibre were smaller in palms and plantae than in other parts of the body. (2) There is no abrasion collar as typically found in other regions. (3) The corneum of epidermis around the entrance hole is lifted off and torn radially. These unusual findings are most probably the result of the particular texture of the palmar and plantar epithelium.

Morphology of injuries by "humane killer" (livestook stunner) (author's transl)

1 short synopsis deals with the general features peculiar to injuries by captive bolt "humane killer" (specifically the types with two opposite outlets for the explosion gases). When the bolt strikes the body at an acute angle, both the wound and the adjacent skin usually show some particular signs: normally the entrance hole is accompanied by two roundish or elliptic zones of blackening due to the diverging smoke conduits. Variations in shape and location of the foulings indicate an oblique holding of the instrument and often even reveal the degree of inclination. Another characteristic is caused by the conically grooved end of the steel bolt: the asymmetric sickle-shaped broadening of the "abrasion collar" reliably points out the direction of fire. Sometimes the entrance hole in the skull is accompanied by semicircular frame-like fracture lines which mostly are situated on the same side as the unilateral abrasion. The cauistic part includes one homicide and eight suicides. Among the latter group one case deserves special attention because the man in question was capable of shooting a second time into his forehead. Three persons tried to ensure the fatal outcome by combining the "humane killer" - injury with concommitant hanging.

Dry ice now used in .22 caliber guns : L. Y. Yont. ( Refrigerating Engineering, Vol. 44, No. 2

Test shots at cloth and at human skin from autopsy material were performed with 7.62 mm Tokarev (TT), 9 mm Makarov (PM) and 9 × 19 mm Glock 19 pistols, using common ammunition.The largest central material defects, with fibre deformation in cotton, the largest burn holes in polyester, and also many fibre defects caused by the perforation of powder, were produced in shots from the TT at all distances. Tears in the cloth were longest in the case of the TT at 1 cm and were present at 3 cm, whereas the shots from the PM and the Glock 19 did not leave tears. There were small tears of the edges of the skin defect from shots fired from the TT at 1 and 3 cm. On cloth-soot deposits at 3 and 5 cm, the radial structures of soot resembled a cobweb (the TT), and radial branching structures (the PM) of soot were seen. Some shots from the PM left four shafts of rays of soot and formed the bullet wipe with four narrow and four wide sections, indicating the form of rifling. In the soot deposit from the Glock 19 with hexagonal rifling, hexagonal or polygonal or petal-like areas were visible. On skin, the soot zones were less distinct. The Glock 19 (at 3 and 5 cm) left a lot of gunpowder particles densely around the cloth and skin defect. The least powder left on the cloth and skin was by the PM.On histological tissue sections, in shots from the TT, a lot of soot and gunpowder residue particles in the epidermis and in both layers of the dermis, and intraepithelial tears and recesses containing soot, were seen. The PM left fine soot and only a few gunpowder particles in the epidermis and in the papillary layer of the dermis. The Glock 19 produced the least soot and a lot of gunpowder particles. The soot and most of the gunpowder particles were present on the tissue sections, which originated from the central area around the skin defect and were detected in the epidermis and in both layers of the dermis. Some tears and recesses in the epidermis were also seen. The further the distance from the centre of skin defect to the periphery, the depth of the penetration of the powder into the skin decreased.