“飘弹”案件的现场勘查与尸体检验1例

“飘弹”案件的现场勘查与尸体检验１例候安山（新疆兵团农七师公安处；奎屯８３３２００）“飘弹”是指高速飞行的枪弹弹丸在触及水面或其它较松软的物体平面（如耕地、积雪、流沙等）而向上飘起的现象。因其形成机制类似于用石片在水面上“打水飘；，故称之为“飘弹”。...     

玻璃雨飞溅高度及分布的实验研究

目的研究平板玻璃打碎后玻璃雨的飞溅高度及空间分布,从而为玻璃物证提取和现场分析提供依据。方法应用自制的实验装置,模拟嫌疑人手持硬物击碎窗户玻璃,收集窗户下地面上和打击者处飞溅的玻璃微粒,对颗粒大小、散布区域进行统计分析,并与通过动力学计算得出的分布进行比较。结果在距离窗户0.5m处,玻璃颗粒的飞溅高度可高于玻璃上相应来源点的高度;较小颗粒有较大的飞溅范围。结论玻璃雨颗粒大小分布和空间分布规律对于嫌疑人身上、头部玻璃物证的提取以及案件的现场分析有十分重要的意义。     

行为分析在命案现场重建中的应用

侦查员或现场勘验人员在进行现场分析时,可充分利用勘验过程中发现的人的活动痕迹,同时结合人体损伤特征,对人的行为进行分析、还原,达到现场重建的目的。本文介绍了一起出租屋内的死亡案件,现场勘验人员利用现场勘验和尸体检验情况,成功地对现场中人的活动轨迹进行了分析,完成了现场重建,为判断案件性质提供了重要的技术支持。     

刑事技术在涉枪案侦破中的作用

就侦破涉枪案件而言,如何发挥刑事科学技术在侦破涉枪案件中的作用,是打击涉枪犯罪的一个十分重要的问题。在枪击案件中可利用的痕迹物证比较多。如根据枪击案件现场射击痕迹(弹孔、弹道、射击残留物等)及现场的其他物证(弹头、弹壳),经过分析、检验,可确定枪种,发射枪支,判断是几支枪发射,并据此枪种的特征参数和条件(如弹重、弹径、弹形、初速、落角及气象条件等)进行弹头诸元计算,以划定侦查范围或解决证实犯罪所需要的诸种问题。实践证明,公安机关只有高度重视利用刑事技术在涉枪案件侦破中的作用,切实加强领导,充实技术力量,不断培养技术队伍,提高技术水平,才能更有效地打击涉枪犯罪。     

DNA检验确定子弹弹着点

在室内枪击案现场，为了确定射击的位置、方向、角度,更加真实、准确地还原现场，需要明确子弹射击的弹道轨迹，这就要求首先要确定弹着点，通常的方法足根据凹痕的痕迹特征以及微世物证的检验结果来确定。     

根据损伤形态准确判断拽头磕碰致伤2例

<正>拽头磕碰伤是指行为人拽着被害人头发使头部往地面或墙壁撞击所造成的损伤。其力的作用方式属减速运动型，与坠落伤和摔跌伤相同。拽头磕碰伤常见于刑讯逼供、非法拘禁和虐待伤害等类案件。致伤现场常无目击证人，或目击者不作客观反映，当造成严重后果后，行为人多谎称伤(死)者系因摔跌所致。由于拽头磕碰伤与摔跌伤的暴力作用方式相同、损伤形态相似，因而，从法医学角度往往难对其作准确判定。现报道2例。     

犯罪心理痕迹在现场重建中的应用

犯罪手段智能化、现代化在各类案件中目益彰显，与之伴随的是案件现场中遗留痕迹物证越来越少，在物证缺少的情况下，人们越来越重视另类痕迹——犯罪心理痕迹在侦查破案中的运用。作者对犯罪心理痕迹与现场重建两个概念以及二者之间的联系进行了分析，提出了自己的看法并针对犯罪心理痕迹在现场重建过程中的理论基础、应用原则、应用的具体步骤和应用中应注意的问题等方面作了比较系统的阐释，形象化的说明了犯罪心理痕迹在现场重建中的应用。     

玻璃破碎的物证分析研究

玻璃碎片及形态是案发现场常见的物证形式,开展对玻璃的物证分析研究,能够确定玻璃的来源与种类,推断玻璃破碎原因等,为案件的取证、重建和侦破提供线索和证据。简要介绍了常见玻璃的种类,分析了玻璃破碎的根本原因,总结了低速冲击和高速冲击下玻璃破碎的形态特征,还从玻璃碎片收集和检验两个方面探讨了玻璃实体物证的分析。     

体内弹道射击角度的计算与分析

目的　推断被枪击者在中弹瞬间所处的位置和姿势以及枪支击发时的位置。方法　采用立体几何作图法和三角函数计算法进行体内弹道射击角度计算。结果　可以准确计算枪弹弹道与人体解剖学三维断面———矢状面、冠状面、水平面产生的角度。结论　可以确定被枪击者中弹瞬间的位置及体位或枪支击发时的位置 ,对分析案件性质有非常重要的法医学意义     

刑事弹道计算机分析系统的研究

本文介绍了刑事弹道计算机分析系统的原理和方法,利用该系统,给定发射角或入射角以及枪种,可自动计算出弹道上任意一点处的射程、射高、射角、速率以及动能等参数.     

Recovery and evaluation by cytologic techniques of trace material retained on bullets

Fragments of tissue, intermediate targets, and debris related to firing are embedded in the fine striations and deforming edges of bullets. Because most of these fragments are too small to visualize and process as histologic sections, this material is usually washed away when the projectiles are cleaned following removal at autopsy. By preserving the rinsing material that results from routine cleaning of projectiles, it may be possible to evaluate adherent material from the bullet by cytologic techniques, including filter preparations, cell blocks, and smears of macroscopic tissue fragments. Bullet-wash cytology produced cellular elements, tissue fragments, and inert material from intermediate targets. Different tissue elements could be documented with a given projectile; this information could be utilized to document the path of a bullet through the body or intermediate target. This initial study suggests that low- and high-velocity projectiles produce different types of tissue debris, with much more fragmentation and scarcity of cellular components in the high-velocity rounds. Inert material, resulting from intermediate targets, such as clothing, as well as gunshot residue on the bullet or debris from the barrel could be distinguished on preparations. There was a difference in tissue representation of adherent material on the bullet; connective tissue, mesothelial coverings, and fragments from organs with higher elastic and cohesive properties were seen with much greater frequency on the filters than were loosely cohesive and friable organs such as liver and spleen. The cytologic preparations from projectile washings reflect both the path taken by the bullet and the ballistic damage to the organs. Thus, the cytologic evaluation of bullet washings may be useful in the incorporation of gunshot wound evaluation to support documentation of the trajectory of the projectile.     

Injuries of the Head from Backface Deformation of Ballistic Protective Helmets Under Ballistic Impact

Modern ballistic helmets defeat penetrating bullets by energy transfer from the projectile to the helmet, producing helmet deformation. This deformation may cause severe injuries without completely perforating the helmet, termed “behind armor blunt trauma” (BABT). As helmets become lighter, the likelihood of larger helmet backface deformation under ballistic impact increases. To characterize the potential for BABT, seven postmortem human head/neck specimens wearing a ballistic protective helmet were exposed to nonperforating impact, using a 9 mm, full metal jacket, 124 grain bullet with velocities of 400–460 m/s. An increasing trend of injury severity was observed, ranging from simple linear fractures to combinations of linear and depressed fractures. Overall, the ability to identify skull fractures resulting from BABT can be used in forensic investigations. Our results demonstrate a high risk of skull fracture due to BABT and necessitate the prevention of BABT as a design factor in future generations of protective gear.     

Ballistic impact of hollow-point ammunition on porcine bone

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

Study of unusual phenomenon of contact firing on gelatine block using .38 Special revolver--forensic importance

Gunshot wounds in suicide cases are self-inflicted wounds. Self-inflicted wounds in suicide cases are usually caused by contact firing and are of great forensic significance. Evaluation of contact wound may be associated with difficulties if the bore gets obstruction prior to firing. This paper investigates the phenomenon and interprets the results of test firing conducted on 20% gelatine block at 10 degrees C, using .38 Special revolver with obstruction of a bullet in the bore. Test firings were conducted in three different muzzle-target contact conditions keeping the muzzle pressed against the gel block in each case. The physical evidence and the wound ballistic parameter namely bullet track, remaining velocity of the bullets and volume of permanent cavity have been studied. When compared with the results of contact firing conducted with the same firearm without having any bore obstruction under similar conditions, it has been found that the physical evidence and the wound ballistic parameters would be helpful for interpretation of such unusual incidents for forensic inference.     

Upon a failure to equal entry and exit wounds: a possible case of tandem bullets in view of the literature

Forensic medicine specialists take account of the projectiles remaining in the body when determining whether there are an equal number of entry and exit wounds. The absence of projectiles should suggest blank cartridges, a single exit wound despite several firings and bullet embolization, whereas the presence of more projectiles than expected may indicate tandem projectiles and multiple projectiles entering through the same hole. Radiological examination of the whole body, follow-up of the bullet trajectories, examination of the clothes, and examination of the gun and projectiles play a key role in solving difficult cases. We review such situations based on a case of tandem bullets. Two 7.65-mm bullets created lethal wounds entering through a 32-year-old victim's neck followed the same trajectory to a certain point and diverted. We discussed the possibilities in cases that show inequalities between entry and exit wounds, in light of relevant literature.     

Behavior of expelled glass fragments during projectile penetration and perforation of glass

Bullets striking common forms of flat glass with an orthogonal intercept angle result in a cloud of ejected glass fragments that are in concert with the exiting bullet's flight path. This is not the case with strikes at angles other than orthogonal. In these situations, the expelled glass fragments follow a very different course from that of the exiting projectile. This is both counterintuitive and a potential source of serious error in the evaluation and reconstruction of a shooting victim's position and orientation at the moment the victim was struck by a bullet that has passed through a nearby source of glass such as a vehicle side window or a window in a building. The flight path of the ejected glass fragments is, however, predictable and is dictated by the orientation of the plane of the glass opposite the projectile's impact site.In all cases, these expelled glass particles have considerable velocity and can produce pseudostippling of the skin in individuals located downrange of bullet-struck glass and near the projectile's exit site. The distribution and location of such pseudostippling and its relationship to the associated bullet hole in glass have important reconstructive value. A proper and reliable reconstruction of the victim's position in such cases will require the integration of scene information with the autopsy findings.     

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

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

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

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