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.     

近距离枪弹创身入口残留物的能谱测定

对１４例近距离人体枪弹创射入口的创周皮肤和创道内组织分别作了能谱测定，结果发现，创周皮肤和创道内组织上的金属成份有着异，而与异物颗粒形态无关，创道内主要为弹头成份，创周为火药成份。     

Planned Complex Occupation‐related Suicide by Captive‐bolt Gunshot and Hanging*

Abstract: Planned complex suicides are committed by using two or more previously planned methods simultaneously to make sure that death will occur even if one method fails. Herein, we presented a case of occupation‐related planned complex suicide, committed by captive‐bolt gunshot and hanging. A 29‐year‐old man, who worked as a butcher, was found dead in the stable, hanging by the neck with a captive‐bolt gun embedded in the forehead region of his head. The hanging was complete. Along the bolt canal were bone fragments, and at the end of the path was the punched‐out fragment of the skin and soft tissue. There were no fractures of the hyoid bone and laryngeal cartilages, and a superficial hemorrhage was present in the right sternocleidomastoid muscle. Our case underlines the utility of forensic autopsy and death scene investigation in reconstructing the mechanism of death, as well as the dynamics of the event.     

Gunshot wounds of the head in soldiers wearing military helmets-- general aspects and experiments and observations on the biomechanics and wound morphology

With respect to wound ballistics, the situation is different if the person wearing a military helmet suffers head injuries from a bullet. The mechanisms of injury were investigated in four experimental series and supplemented by a case history. The study showed surprising results: in the majority of cases, the helmet does not protect the wearer, but instead intensifies the damage caused by the bullet. The reasons for this phenomena are changes in the stability of the projectile and deformation of or damage to the bullet. All of these mechanisms result in the bullet striking the tissue with higher energy. In this investigation, Kevlar helmets were also tested, which are not penetrated by 9 X 19 mm parabellum bullets. Even so, however, severe injuries of the skull and brain can occur because the projectile causes intensified impressions on the skull under the helmet and, in addition, an acceleration of the head.     

Gunshot residue particle velocity and deceleration

The velocity of over 800 gunshot residue particles from eight different sources was determined using high speed stroboscopic photography (spark gap light source). These particles were found to have an average velocity of 500 to 600 ft per second. Many particles acquired considerably higher velocities. Thus, the particles have sufficient energy to embed themselves within certain nearby targets like skin or fabric. The relatively high velocity that the particles acquire explain the formation of stippling on skin in close proximity to a muzzle discharge. These findings also indicate little influence of air currents on particle behavior near the muzzle. The deceleration of less than 100 particles during a 100-microsecond interval was also calculated. The particles experienced rapid rates of deceleration which would explain why few particles are found in test firings beyond 3 ft from the muzzle of a discharged firearm. Because of their relatively high velocity, normal wind velocity would not be expected to significantly influence their motion near the muzzle.     

Macroscopic,Microscopic, and Chemical Assessment of Gunshot Lesions on Decomposed Pig Skin

Abstract: Very little literature exists on gunshot wounds on decomposed material. In this study, seven pig heads underwent a shooting test. Entrance wounds from the first head underwent neutron activation analysis (NAA) and histological testing immediately after the firing test; the other six heads were exposed to two different environments (open air and soil) and analyzed by radiochemical and histological tests every 15 days. Gunshot wounds in air maintained their morphological characteristics, and those in soil showed severe alteration after 5 weeks. Microscopic testing verified positive results for lead in all gunshot wounds in open air, whereas in most of those in soil lead could not be detected. Radiochemical analysis performed by NAA yielded for all gunshot wounds but one antimony quantities in the range of 0.07–13.89 μg. In conclusion, it may be possible to detect residues of antimony even in degraded tissues.     

A preliminary study on the changes of expression of PDGF-beta,PDGFR-beta,TGF-beta 1, TGFR,bFGF and its relationship with the wound age in wound healing

OBJECTIVE: To explore the relationship between the expression change of cytokines and the wound age during the healing process of rats skin wound. METHODS: Immunohistochemical and image-analysis methods were performed on vital skin wounds(after incision 0.5-168 h am) and postmortem damage(after incision 0.5-6 h pm). RESULTS: The expression of the cytokines PDGF-beta, PDGFR-beta, TGF-beta 1, and bFGF in the epithelial cells was already enhanced since 0.5 h am after damage and their strongest expression reaction was seen at 24-96 h am. In addition, the expression of PDGF-beta, PDGFR-beta, TGF-beta 1 and bFGF was also found in the macrophages and the fibroblasts of the granulation tissue, and the expression changes in the postmortem damage group showed that the skin tissue within 0.5-3 h after incision showed immunohistochemical changes but weakly expression and 3 h thereafter no any change was found. CONCLUSION: The expression characteristics of the above mentioned cytokines in wound repair should be related to the wound age and it reminds therefore that they may be used as immunohistochemical criteria for accurate determining the wound age.     

Gunshot fatalities in children and adolescents in New York City

We reviewed the case records of all fatalities due to gunshot wounds in children and adolescents under 19 years of age in New York City from 1996 to 2000. The epidemiological profile, circumstances, toxicology results, location, and injuries were examined. There were 263 deaths: 242 homicides, 17 suicides, and 4 accidents. Among the homicides, 96% involved Black or Hispanic and 68% involved 17 and 18-year-old decedents. There were 11 times as many male as female homicides. The detection of ethanol and/or illicit drugs was 56% in the homicide and 53% in the suicide groups. Suicide notes were found in 18% of suicides, and an additional 35% verbally expressed a plan to commit suicide. Most suicides (77%) were in the home and half of the homicides occurred on the street.     

Effects of Decomposition on Gunshot Wound Characteristics: Under Moderate Temperatures with Insect Activity

Abstract:  Previous studies document characteristics of gunshot wounds shortly after they were inflicted. This study was conducted to determine if the early stages of decomposition obscure or alter the physical surface characteristics of gunshot wounds, thereby affecting the quantity and quality of information retrievable from such evidence. The study was conducted in August and September, 2005 in Nova Scotia, Canada in forested and exposed environments. Recently killed pigs were used as research models and were shot six times each at three different ranges (contact, 2.5 cm, and 1.5 m). Under these test conditions, the gunshot wounds maintained the characteristics unique to each gunshot range and changes that occurred during decomposition were not critical to the interpretation of the evidence. It was concluded that changes due to decomposition under the conditions tested would not affect the collection and interpretation of gunshot wound evidence until the skin was degraded in the late active or advanced decay stage of decomposition.     

Analysis of Gunshot Residue and Associated Materials—A Review

Abstract: A comprehensive review of the scientific literature on gunshot residue (GSR) is presented. Aspects of both inorganic and organic GSR are discussed, from formation and distribution, to sample collection, preparation, and analysis using a variety of techniques. The interpretation of GSR results is also considered including issues surrounding the contamination, distribution, and transfer of GSR. Potential problems with ulterior sources of GSR like particles have been reported in the literature. For example, particles from environmental and occupational sources have been highlighted as exhibiting similar chemical and morphological characteristics to GSR. These findings are put into context with regard to interpreting samples. A move toward a “case by case” approach is argued to be more preferable to a “formal” classification system where possible. The analysis of both inorganic and organic compositions of residue samples as well as morphological considerations is considered to be a more ideal approach to GSR analysis, whereever practicable.     

Effects of Decomposition on Gunshot Wound Characteristics: Under Cold Temperatures with No Insect Activity

Abstract:  Information on gunshot wound characteristics has been well documented; however, there is little documented information on the effects of decomposition or environmental conditions on gunshot wound characteristics. This study was conducted in order to determine if decomposition would obscure or alter the physical surface characteristics of gunshot wounds when exposed to a low temperature environment. The study was conducted from November 2005 to January 2006 in Nova Scotia, Canada in forested and exposed environments, with air temperatures between −10°C and +10°C. Pigs were used as human models and were shot six times each at three different ranges (contact, 2.5 cm, and 1.5 m). Gunshot wound characteristics persisted until the wounds were covered with ice and snow, after which changes were observed. The changes were recognized as being unique to the different ranges of gunshots and it was concluded that changes due to decomposition under the conditions tested would not affect the collection and interpretation of gunshot wound evidence.     

切创后细胞自噬及炎症因子的表达与损伤时间的关系

目的观察小鼠皮肤切创后不同时间细胞自噬与炎症细胞因子的变化,同时探讨这些变化与损伤时间之间的关系。方法采用RT-PCR及West-blot方法检测小鼠皮肤切创组织在不同时间Beclin-1、LC-3、IL-1α、IL-1β、MCP-1的基因表达及蛋白表达。结果皮肤切创后早期IL-1α、IL-1β基因的表达及蛋白表达水平有所升高,12小时达到最高值,而后呈下降的趋势;MCP-1的表达在损伤后6h开始升高,48h达到最高值,72h有所下降,而Beclin-1、LC3基因及蛋白表达在组织损伤后6h开始升高,24h到达到最高值而后下降。结论小鼠皮肤组织切创后细胞自噬的启动及自噬的最高值明显晚于炎性细胞因子的启动及炎症因子表达的最高值,实验发现当细胞自噬水平达到最高时,炎症因子的水平则开始表现为下降的趋势。这可能是随着切创组织中炎症因子释放的增多激活了细胞的自噬,而当自噬水平达到一定的程度又抑制过度的炎症反应。自噬与炎症因子的表达随着小鼠皮肤创面损伤后不同时间呈现出一定的变化规律,这为组织损伤后损伤的时间推断提供一定的参考。     

Gunshot residue in Chicago police vehicles and facilities: an empirical study

Suspects in shooting investigations in Chicago are routinely transported in department vehicles and detained in department facilities prior to gunshot residue (GSR) evidence collection. The GSR test results are used to associate the suspect with primary exposure to GSR. The potential for these vehicles and facilities being sources of secondary GSR contamination needed to be determined. A total of 201 samples were collected from randomly selected vehicles and detention facilities. The sampling collected trace materials from surfaces that suspects' hands may contact during the arrest process. These samples were examined for the presence of GSR particles using scanning electron microscopy. Upon completion of the automated analysis, those particles that met an initial GSR screening criterion were relocated and reanalyzed. The locations where GSR particles were recovered allowed us to make recommendations to the Chicago Police Department with regard to transporting and detaining these suspects. The low number of GSR particles recovered suggests that the potential for secondary contamination, although present, is relatively low.     

General and plastic surgery devices; classification of the nonresorbable gauze/sponge for external use, the hydrophilic wound dressing, the occlusive wound dressing, and the hydrogel wound dressing. Food and Drug Administration, HHS. Final rule

The Food and Drug Administration (FDA) is classifying the nonresorbable gauze/sponge for external use, the hydrophilic wound dressing, the occlusive wound dressing, and the hydrogel wound dressing into class I (general controls). FDA is also exempting these devices from premarket notification procedures. This action is being taken under the Federal Food, Drug, and Cosmetic Act (the act), as amended by the Medical Device Amendments of 1976 (the 1976 amendments), the Safe Medical Devices Act of 1990 (SMDA), and the Food and Drug Administration Modernization Act of 1997 (FDAMA).     

Gunshot residue patterns on skin in angled contact and near contact gunshot wounds

The goal of this study was the reproduction of shape and pattern of gunshot residues in near contact and contact gunshot wounds by a series of experimental gunshots on a skin and soft tissue model. The aim was to investigate the shape and direction of soot deposits with regard to the muzzle according to different muzzle-target angles, firing distances, type of ammunition and weapon and barrel length. Based on a review of the literature and on the results of the experiments the authors could make the following statements of gunshot residues in angled contact and close contact gunshot: (1) gunshot residues on the target surface can be differentiated in a "inner" and "outer powder soot zone"; (2) the outer powder soot zone is much less visible than the inner powder soot zone and may lack on human skin; (3) with increasing muzzle target distance both inner and outer powder soot halo increase in size and decrease in density; (4) in angled shots the inner powder soot halo shows an eccentric, elliptic shape which points towards the muzzle, regardless of ammunition, calibre and barrel length; (5) the outer powder soot points away from the muzzle in angled contact and close contact shots.     

Gunshot residue testing in suicides: Part I: Analysis by scanning electron microscopy with energy-dispersive X-ray

Several different methods can be employed to test for gunshot residue (GSR) on a deceased person's hands, including scanning electron microscopy with energy-dispersive x-ray spectroscopy (SEM-EDX) and inductively coupled plasma-atomic emission spectrometry (ICP-AES). Each of these techniques has been extensively studied, especially on living individuals. The current studies (Part I and Part II) were designed to compare the use and utility of the different GSR testing techniques in a medical examiner setting. In Part I, the hands of deceased persons who died from undisputed suicidal handgun wounds were tested for GSR by SEM-EDX over a 4-year period. A total of 116 cases were studied and analyzed for caliber of weapon, proximity of wound, and results of GSR testing, including spatial deposition upon the hands. It was found that in only 50% of cases with a known self-inflicted gunshot wound was SEM-EDX positive for at least 1 specific particle for GSR. In 18% of the cases there was a discernible pattern (spatial distribution) of the particles on the hand such that the manner in which the weapon was held could be determined. Since only 50% of cases where the person is known to have fired a weapon immediately prior to death were positive for GSR by SEM-EDX, this test should not be relied upon to determine whether a deceased individual has discharged a firearm. Furthermore, in only 18% of cases was a discernible pattern present indicating how the firearm was held. The low sensitivity, along with the low percentage of cases with a discernible pattern, limits the usefulness of GSR test results by SEM-EDX in differentiating self-inflicted from non-self-inflicted wounds.     

创道的超声检测及法医学意义

陈旧性创道长度的测定是法医学鉴定中的难点,长期以来没有得到应有的重视。随着高频二维超声和彩色多普勒成像技术的运用,目前已可以准确地定量创道的长度。通过两例损伤程度鉴定案例,并结合超声图像,说明超声检测在损伤程度鉴定中有重要的价值,可以为损伤程度的鉴定提供有价值的科学证据。     

Caspase与皮肤损伤

Caspase家族,目前已知至少由14个成员组成,该家族成员在细胞凋亡过程中发挥着重要作用。实验研究表明,在皮肤损伤及愈合过程中,伴随着Caspase的活化和表达,这可能与Caspase诱导细胞凋亡的发生有关。深入研究Caspase在皮肤损伤及愈合过程中的作用机制,有望为皮肤损伤的治疗和法医学损伤时间的推断提供新的方法。本文综述了Caspase家族的生物学特性以及Caspase在皮肤损伤及愈合过程中的研究进展,认为Caspase在皮肤损伤及愈合过程中发挥重要作用,具有深入研究的必要。     

A distant-range, suicidal shotgun wound of the back

The case being reported is one of a shotgun fatality with a thoracic back wound. A 23-year-old man was shot from a distance with trajectories going from back to front and on a nearly horizontal level. These findings observed in the autopsy could represent homicide, but scene investigation and police records were interpreted and it became clear that the case was suicide. Thus, this case shows that the determination of the manner of death requires a careful forensic investigation including autopsy findings, scene investigation, and reconstruction of the events.     

An unusual entrance wound associated with rimfire rifles.

In many cases of self-inflicted contact wounds of the head with rimfire rifles, we have noted that the entrance wound appears unusual: in 50% of cases studied, a pencil-like extension or zone of blackened and seared skin extends downward from the entrance. The most probable cause for the appearance of this wound is a momentary break in contact between the muzzle and skin as the victim reaches for the trigger with resultant escape of a jet of hot sooty gas. Whereas not unique for rimfire rifles, such a wound from a handgun is uncommon.