用射人客体深度测算枪支杀伤力

目的　研究涉案枪支的杀伤力鉴定标准。方法　采用直尺测量方法 ,分别测量制式枪弹、送检枪弹射入同一客体的深度及送检枪弹径。将制式枪弹各数据及送检枪弹径代入新公式 (d1/d2 ) 0 75(h1/h3) 0 7=v1m1/ 5 .2 4d2 ,得出送检枪具有最低杀伤力时射入客体深度h3,该深度标准与送检枪弹射入客体深度h2 比较后可判断杀伤力。结果　该方法计算出的h3值为一区间范围 ,若被检枪弹射入客体深度在区间右侧 ,有杀伤力 ,在区间左侧 ,无杀伤力。结论　用射入客体深度进行枪支杀伤力鉴定 ,方法简单、实用 ,有助于探讨建立枪支杀伤力标准。     

Renal artery bullet embolism.

Bullet embolism is a well-recognized phenomenon. While bullet embolism is not common, renal artery bullet embolism appears to be very rare. We report three cases of bullet embolism to a renal artery. Autopsy findings and bullet types are presented. Such cases are of particular interest to both the medical examiner and the clinician. Failure to consider this phenomenon clinically could lead to infarction of a kidney. A consideration of this phenomenon at autopsy could shorten the dissection time required to retrieve the bullet.     

Compositional variation in bullet lead manufacture

The concentrations of antimony, copper, tin, arsenic, silver, bismuth, and cadmium in lead alloys produced by two smelters and one ammunition manufacturer were determined using inductively coupled plasma-atomic emission spectrometry. These element concentrations were used to measure the variations in composition of lead products that result from various processes involved in the manufacture of lead projectiles. In general, when a pot containing molten lead is used to cast a number of objects, these objects are similar, although not necessarily analytically indistinguishable in their elemental compositions. In each subsequent step in the processing of lead at the smelter and at the ammunition manufacturer, the size of an individual homogeneous melt of lead decreases as more distinct compositions are formed as a result of remelting and mixing of sources, including lead scrap. The ammunition manufacturer in this study produced at least 10 compositionally distinguishable groups of bullet wire in a 19.7-h period. The largest group could potentially be used to produce a maximum of 1.3 million compositionally indistinguishable 40 grain bullets.     

Reproduction of atypical bullet exit wounds

Contradictory findings from experiments designed for the reconstruction of the circumstances in crimes committed with firearms induced us to systematically investigate the conditions leading to the occurrence of non-typical bullet exit wounds. For this purpose, skin samples and pig heads were fired at with different types of small arms and, on the exit side, the skin was brought into contact with various materials. The bullet exits were investigated morphologically and by means of emission spectrum analysis. The results from these investigations are classified and discussed.     

Forensic significance of bullet lead compositions

The concentrations of seven elements in projectile lead specimens received as evidence were used to assess the frequency of the occurrence of two unrelated samples having indistinguishable compositions. A set of data from 1837 samples was selected for this study from a sampling of 23,054 lead bullets and shot pellets received as evidence in the FBI Laboratory over the period 1989 through 2002. The method used for selection of samples from case submissions ensured that no two samples of the same general type from the same case were included and that no bias was introduced concerning representation of manufacturers or production sources. A total of 1,686,366 pairwise lead sample comparisons were made using the concentrations of the elements Sb, Cu, As, Ag, Bi, Sn, and Cd using a match criterion of two times the sum of the standard deviations of the paired samples. Of the 1837 samples, 1397 samples, or 76%, are distinguishable from every other sample in this study. The total number of indistinguishable sample pairs is 674, for a frequency of 1 out of every 2502 comparisons. The frequency of occurrence of matching samples decreases as the number of measured elements is increased and as the precision of the measurements improves. For bullets in which all seven elements were determined, the match frequency is 1 in 7284. Compositional comparison of bullet lead provides a reliable, highly significant point of evidentiary comparison of potential sources of crime-related bullets.     

Intravascular bullet embolism to the right atrium

Bullet embolism is a relatively unusual complication of gunshot wounds. Embolism to the right atrium comprises <5% of all reported intravascular bullet emboli. We report an additional case of bullet embolus to the right atrium of a 0.38-caliber bullet following a gunshot wound to the chest. The intracardiac bullet was recognized radiologically on presentation, but the patient was hemodynamically stable and managed conservatively, with the bullet left in place. The missile remained within the heart without clinical significance for several years and was recovered from the right atrium only at the time of autopsy. To the best of our knowledge, this is the first documented case of a 0.38-caliber bullet which embolized to the right atrium and remained inconsequential for an extended period of time.     

跳弹创形态学的实验研究

目的 探讨跳弹创形成的条件,研究跳弹在体内弹道学特点及致伤能力,建立跳弹创的诊断依据。方法选用国产54式手枪及56式半自动步枪,配用51式手枪弹及56式步枪弹以水磨石板为反跳靶体,射击约克夏种猪4头,复制出跳弹创模型12例。观察射入口、创道及着弹点特征。结果 跳弹的形成受靶体性状、弹头形态和速度、入射角与反跳角等条件因素的影响;在相同条件下高初速尖型弹头的反跳角<低初速圆型弹头;创道无明显瞬时空腔效应;根据实验结果建立了6项诊断依据。结论 正确诊断跳弹创对射击方向和距离、重建弹道、分析枪击目的、评估损伤程度有实用价值。     

Gunshot injury caused by a training bullet]

In the course of a scuffle a 50-year old man has been shot by a revolver. The culprit and witnesses state, there has been only one shot, whereas the victim declared having been shot twice. The medico-legal investigation revealed a gunshot wound that passed through the left thigh, a grazing shot of the right hand and a superficial lesion of the skin at the forehead with sprinkled gunshot residue in the epidermis. The investigation confirmed the statement of the victim: the first shot to the forehead was caused by a plastic training cartridge, the second to the right hand and thigh by a cartridge loaded with an ordinary bullet.     

The effect of tempered glass on bullet trajectory

It was determined that tempered glass automobile windows may severely influence the trajectory of .38 Special projectiles. In replicating an actual case situation, deflections as great as 26.4 degrees were observed with jacketed hollow-point ammunition, and as high as 10.8 degrees for lead ammunition.     

Estimation of bullet striation similarity using neural networks

A new method that searches for similar striation patterns using neural networks is described. Neural networks have been developed based on the human brain, which is good at pattern recognition. Therefore, neural networks would be expected to be effective in identifying striated toolmarks on bullets. The neural networks used in this study deal with binary signals derived from striation images. This signal plays a significant role in identification, because this signal is the key to the individually of the striations. The neural network searches a database for similar striations by means of these binary signals. The neural network used here is a multilayer network consisting of 96 neurons in the input layer, 15 neurons in the middle, and one neuron in the output layer. Two signals are inputted into the network and a score is estimated based on the similarity of these signals. For this purpose, the network is assigned to a previous learning. To initially test the validity of the procedure, the network identifies artificial patterns that are randomly produced on a personal computer. The results were acceptable and showed robustness for the deformation of patterns. Moreover, with ten unidentified bullets and ten database bullets, the network consistently was able to select the correct pair.     

Path of bullet and injuries determined by radiography

Radiography is commonly used to find bullet pathways in forensic pathology. In the case presented here, a man had sustained multiple gunshot wounds and one bullet could not be traced. A radiograph was used to find the bullet and showed an interesting bullet pathway. By observing the bullet pathway on a radiograph, sometimes we can surmise the victim's body posture at the time of an incident.     

Radiodense bullet wipe around osseous entrance gunshot wounds

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

The effect of the THV bullet in animal tissue

The Très Haute Vitesse (THV) bullet was introduced to meet the requirements of law enforcement officers, as an alternative to larger calibre fully jacketed bullets, since expanding or exploding bullets are not relevant in Europe. To examine the effect of the THV bullet in tissue, especially the size of the lesion and the degree of overpenetration, 11 recently killed pigs were shot with the weapons used by the Danish Police Force and a 9-mm pistol for reference. The ammunition was THV in the calibres 7.65 mm, 0.38, and 9 mm, using conventional fully jacketed bullets for comparison. The lesions were considerably larger when the THV bullet was used, the entry wound in particular, being roughly twice the diameter in the case of the THV bullet as compared to the fully jacketed bullet of similar calibre. Only one 7.65-mm THV bullet overpenetrated the target when fired against the thorax or abdomen of the pigs and then with only minimal residual energy. All fully jacketed 7.65-mm bullets, all 0.38 bullets, with the exception of one THV bullet, and all 9-mm bullets overpenetrated the target. The 7.65-mm THV bullet produced a lesion which in its extent resembled that of the fully jacketed 9-mm bullet, and should be a suitable alternative for the Danish Police Force.     

Pseudo-gunpowder stippling caused by fragmentation of a plated bullet

In this report we present a case of pseudo-gunpowder stippling caused by fragmentation of a plated bullet. Investigation of the incident revealed absence of an interposed target, no evidence of ricochet, and a normally functioning, undamaged weapon. Electroplated ("plated" or "coated") bullets are relatively uncommon. They look similar to jacketed bullets in that the lead core is covered by a copper-colored jacketlike material. However, the copper-colored plating material is thinner than the typical jacket material. In certain instances, the plating may strip away from the lead core during transit through the barrel of the weapon and can produce injuries that mimic gunpowder stippling. Forensic pathologists are advised to be aware of this phenomenon. Misinterpretation of such wounds could result in improper classification of range of fire or improper conclusions about the presence or absence of an interposed target or ricochet.     

Distribution of textile fibers in the path of a bullet

Twenty-one blocks consisting of 20% gelatin were fired at using firearms of the long rifle caliber .22 and .357 Magnum. The frontal area of these blocks was prepared with textile coverings marked with technetium 99m. Two gunshot series of each type were fired at summer, interseasonal, and winter clothing, using different ammunition. The radioactivity of the bombarded blocks was measured by single photon emission computed tomography (SPECT). The results of these gun shot series were presented graphically and compared. Initially (at 2 cm depth), high radioactivity is always detected, which among other things is caused by the defilement of the bullet's surface when shot through the textile covering marked by technetium. The higher radioactivity in the middle and deeper block areas is the result of fiber infiltration. Accordingly, there are greater fiber accumulations in the middle and deeper areas of the path of the bullet. This is the case mainly in thinner clothing (summer). Heavier clothing (autumn, winter) presents a greater obstacle for bullets with greater impact as well. Here, only projectiles having a lesser tendency to deform, as well as a high impact, transport a considerable proportion of textile fibers into the deeper parts of the blocks.     

Automated comparisons of bullet striations based on 3D topography

A system capable of comparing the signatures on bullets in the field of firearms identification is presented. It is based on the recording of the topography of a bullet using laser profilometry. A procedure to derive a one-dimensional array of characteristics out of the recorded data is presented. These so-called feature vectors are compared with similar quantities from other bullets using a correlation technique. Good results were obtained for weapons leaving well-defined characteristics.     

子弹弹头及弹壳成分比较研究

目的对子弹物证进行成分分析可为涉枪案件的侦查提供科学依据。本实验旨在通过研究子弹弹头及弹壳的元素组成快速区分不同子弹,为推断子弹来源提供关键信息。方法收集不同厂家在1958-2019年不同批次生产的多种型号的子弹样品53份,应用扫描电镜能谱法(SEM/EDX)对样品的弹头内芯、弹头披甲和弹壳金属成分进行研究。结果结果显示多数子弹弹头内芯由纯铅构成,部分批次较晚的弹头为铅锑合金,另有两枚批次较早子弹为铁弹头;除六枚5.6mm运动步枪弹的弹头披甲以及四枚791厂样品的弹壳无明显特征外,其余子弹的弹头披甲和弹壳均为三类铜锌合金中的一种:含铜量83.7%~84.7%、87.6%~90.6%以及67.0%~69.8%的铜锌合金。同型号同厂家子弹所使用弹头披甲及弹壳材料的特征相似,同型号不同厂家、同厂家不同型号的子弹弹头披甲和弹壳材料则具有一定差异。近六十年来121厂样品子弹弹头披甲均为含铜量87.6%~90.6%的铜锌合金,弹壳材料为含铜量67.0%~69.8%的铜锌合金,其为该厂固定使用的铜锌合金原材料的可能性较高。791厂样品中有四种型号的子弹弹壳均为含锰量0.7%~0.9%的铁锰合金,这种合金在其他厂家并未出现,其为791厂弹壳特征原材料的可能性较高。结论掌握子弹弹头及弹壳的元素组成特征可以对不同子弹进行有效识别。