根据创口射击残留物推断“5.4”式手枪射击距离的研究

目的利用环境控制扫描电镜/能谱仪（SEM/EDX）研究枪弹创射入口周围射击残留物与射击距离的关系,探讨其能否用于射击距离的判断。方法采用＂＂5.4＂＂式手枪分别在5、10、15、20、30、40、50、60、70、80、90、120cm处射击乳猪皮肤,利用SEM/EDX观察创口周围GSR的分布和成分,并建立回归方程。结果射击距离和GSR颗粒数量之间总体表现为直线关系,并建立了相应的回归方程。当射击距离为10~90cm时,用该方程推断射击距离效果较好。结论检测创口周围GSR可望用于判断“5.4”式手枪的射击距离。     

头发对射击残留物附着的影响

利用射击残留物的存在和分布形态判断枪口与射入口的距离是现场分析的关键之一。然而我们在工作中发现,在对头部射击的案件中,弹孔周围的头发有可能对射击残留物起到屏蔽作用,尤其在贴近距离[1](2cm~5cm左右)射击的时候,绝大部分射击残留物会附着在头发而不是头皮上,本文将以实验和真实案例为基础详细说明近距离射击时头发对射击残留物附着的影响。     

利用颅骨枪弹创骨折类型推断射击方向和顺序的实验

建立利用颅骨枪弹创骨折类型推断射击方向和顺序的方法。使用国产五四式7．62mm口径手枪及五六式7．62mm口径半自动步枪,以3m的距离2次射击16具尸体的头颞部及枕部,造成颅脑贯通创,制成颅骨枪弹射入、出口各32例,并根据定位标记进行观察。结果显示：颅骨枪弹创骨折形态可分为带有斜面的孔状骨折,锁孔状骨折,放射状骨折和环状隆起骨折4种类型,其出现多见于低速枪射击,并与射击方向和顺序有直接关系。根据颅骨枪弹创骨折类型可推断射击方向和顺序。     

利用霰弹弹杯损伤推断射击距离

使用国产12号、16号商品猎枪及相应霰弹,以不同距离射击实验靶纸,研究弹杯损伤变化与射击距离之间的关系。结果表明,射击距离在30cm以内弹杯损伤不明显(P>0.05),30cm～70cm其损伤直径随射击距离增大而明显增加(P<0.001),呈显著正相关性,70cm～3m弹杯翻转与射入口重合,3m以外弹杯逐渐偏离中心弹道而无实际意义。     

92式手枪射击距离与射击残留物分布密度相关性的研究

目的研究92式手枪射击距离与射击残留物分布密度的相关性,为射击距离的推断提供依据。方法选择92式手枪,在带皮的猪肉上覆盖白色棉布,设计了0m,0．1m,0．2m,0．5m,1．0m,1．5m,3．0m,5．0m,10m,15．0m,20．0m,25．0m共12个距离进行射击,提取白棉布上的弹孔圆周和距弹孔2cm的圆周上的射击残留物,利用扫描电镜／能谱仪对不同射击距离遗留在白棉布上的射击残留物进行检验。结果白棉布上射击残留物分布密度与射击距离呈负相关的关系。结论根据棉布上射击残留物的分布密度,能够推断射击距离,对涉枪案件中射击距离的判断有一定的参考价值。     

9mm警用转轮手枪橡胶弹射入口的形态特征

目的观察橡胶弹射人口的形态特征,并探讨其法医学意义。方法使用9mm警用转轮手枪发射橡胶弹,在实验动物胸腹部侧面垂直射击,射击距离分别为紧密接触射击（0cm）,相对接触射击（1～6cm）,近距离射击（6-60cm）和远距离射击（60cm～有效射程25m）。92式手枪采取相同方式射击实验动物作为对照。观察射入口的形态特征,制作组织病理学切片,HE染色显微镜下观察。结果橡胶弹接触射击和近距离射击,射入口边缘整齐,有明显的擦拭轮、挫伤轮和火药斑纹;远距离射击,可见射人口边缘撕裂,挫伤轮明显增宽,皮下出血显著;与手枪弹射入口形态特征明显不同。结论9mm警用转轮手枪橡胶弹射入口典型的形态特征,可作为此类损伤的诊断指标。     

飞弹致人死亡1例

1 案情1976年2月13日下午5时许,聊城市某乡村民张某(男,23岁)在李某家中饮酒后返家,出院门不久,李某发现张某忘记拿围巾便去追赶,发现走在前面的张某突然“哎哟”一声,转过身来往回走了几步便倒地死亡.次日进行尸体检验.死者棉衣左胸部有一0.75cm× 0.65cm的破口,衣内棉花上未检见烟灰颗粒,左胸壁锁骨中线第三肋间有一类椭圆形裂伤,长轴0.8cm,短轴0.65cm,创缘较整齐,皮肤内卷,中心组织缺损,有挫伤轮,且左上方挫伤区稍宽于右下方.裂伤周围未检见烟晕颗粒等射击残留物.左肺、心脏及肝脏贯通伤.于右肺底组织内发现口径7.62mm的圆尖形弹头一枚,未穿出肺脏.张某系枪弹损伤导致失血性休克而死亡.李某反映当时未听到明显枪声.围绕张某及有关的人开展调查,无明显他杀因素.后经查实系5公里外一少年用“五六”式7.62mm半自动步枪以大约30度的角度朝天鸣放误射所为,枪弹是利用废旧子弹填塞大量黑火药自制而成.     

64式手枪弹弹头损伤程度与射击距离关系的研究

弹头在与射击客体剧烈撞击过程中所产生的损伤特征是推断射击距离的重要依据。本文对64式手枪弹于不同距离射击墙体后弹头的损伤程度进行研究,探索64式手枪弹弹头损伤程度与射击距离的关系。在射击实验中,用64式手枪和发射药装药量分别为总发射药装药量3/6、4/6、5/6、6/6的64式子弹射击墙体,利用测速仪测量子弹的发射速度并换算得到射击距离,通过体视显微镜观察弹头损伤形态,利用游标卡尺测量子弹撞击面直径、弹头长度并计算得出变形系数。结果表明,射击距离为1~12.33m时,弹头变形严重,呈蘑菇状,而披甲呈爆裂状,铅芯暴露范围大,当其增加至45.57~154.17m,弹头仍呈蘑菇状,部分披甲破裂,暴露出铅芯,当其继续增加至131.59~352.14m,弹头变形程度减小,碰撞面呈扁平状,披甲完整,无铅芯暴露,当其达到425.44~915.81m,弹头变形程度小,碰撞面呈锥形,但弹头表面有明显碰撞和刮擦痕迹;弹头变形系数随射击距离变大而减小,且其下降速率随射击距离增大(尤其当射击距离超过300m时)显著减小。因此,在涉及64式手枪弹射击的案件调查中,可根据枪击现场提取的弹头的损伤程度并结合试射实验结果对射击距离进行推断,但该方法一般只适用于较大范围射击距离的推断。     

利用弹杯损伤推断霰弹创射击距离一例

制式霰弹是用塑料弹杯盛装错弹丸，弹林底部装火药（多为有机火药），用机械压制而成。其弹林前端似“花瓣”状，多为四个“瓣”，故在创道内或现场提取到塑料弹杯域在射入口创线检见弹杯损伤，可确定该创为制式雷弹枪射击所致。霰弹创鉴定射击距离是法医学检验的一个难题。射入口创缘弹杯损伤的形态特征与射击距离有关，利用弹杯损伤可较准确地推断射击距离c笔者曾遇一例，现报告如下。实例李某，男，3O岁。1996年10月20日被人用制式霰弹杀死，死后15h尸检、死者上衣衣领右侧翻领处见一2．4×1．6cm的缺损；右胸上部有一4．2×2．7cm的横…     

霰弹枪损伤判断失误1例

霰弹枪近距离射击时,所形成的损伤具备一般枪弹损伤的特征,但远距离射击时所形成射入口的形态不规则,因表现多种多样,易导致判断失误。笔者遇到1例,现报道如下。1案例资料简要案情张某,男。2004年12月17日20时许被人打伤,右面部有一伤口流血不止,处于昏迷状态,即送往医院,经紧急抢救无效,于当日24时许死亡。现场勘验现场位于某仓库门前。1辆黑色帕萨特轿车头东北、尾西南停靠在大门南面路东侧。车上有散在分布的小块人体组织碎块及血滴。车钥匙掉在车门前下方地面上。车西北侧1m处地面上有30cm×40cm血泊,周围路面上无刹车痕迹及可疑散落物…     

The Physical Effects of Contact and Close‐Distance Gunfire on Sweatshirt Fleece

Powder stippling caused by the impact of propellant particles during close‐distance gunfire has been previously described on skin and solid objects only. Additionally, radial tearing has been described as clear evidence of a contact‐distance shot, requiring no further testing. Patterns of discrete perforating holes (referred to here as “stippling perforations”) and other physical damage on sweatshirt fleece fabrics were prepared. Using the firearm and ammunition in this study, stippling perforations were observed to a maximum muzzle‐to‐target distance of 35 cm (10 inches). In addition, radial tearing and disintegration were present (and often more extensive) at greater than contact distance. The presence of stippling perforations could augment muzzle‐to‐target distance estimates generated using the Griess test, or allow distance estimates when the Griess test is not feasible. Unlike what has been previously reported, testing on the original evidence (or similar substitute) is warranted when physical damage is used to estimate shooting distance.     

A versatile technique for the investigation of gunshot residue patterns on fabrics and other surfaces: m-XRF

With heavy-metal-free ammunitions becoming more and more popular, it is necessary to find methods to visualize patterns of those elements in gunshot residues (GSRs) that are not accessible by chemographic coloring tests. The recently introduced millimeter-X-ray fluorescence analysis (m-XRF) spectrometer Spectro Midex M offers an easy way to record mappings of GSRs containing such elements in order to determine shooting distances as well as the general composition of these particles. A motorized stage enables samples of a maximum size of 20 x 20 cm to be investigated, like fabric, clothes, adhesive tapes (Filmolux films), and polyvinylalcohol gloves of shooter's hands. Human tissues can be measured using a Peltier-cooled specimen holder that is mounted onto the stage. As the spot size of the exiting X-rays lies in the millimeter range, which is adequate for the assessment of the residue patterns for shooting distance determination, a significant reduction in measurement time is achieved compared with mu-XRF methods. Test shots with heavy-metal-free ammunitions were performed on different target materials, like pork skin and fabric, and the elemental distributions of Ti, K, and Ga were determined. In order to show the capability of the spectrometer for conventional lead ammunitions as well, a shot series of 5-100 cm shooting distance and an adhesive tape of a shooter's hand were investigated analogously. A comparison of several methods applied in GSR investigation shows the advantages of the m-XRF method.     

Time periods of GSR particles deposition after discharge-final results

The elemental objects of the research study are: determination of time periods corresponding to gunshot residue particles (GSR) deposition after the shot from selected pistols and a revolver, and evaluation of the deposited particles number. For several shooting experiments were used a pistol CZ model 85, caliber 9 mm Luger with common ammunition 9 mm Luger FMJ Sellier & Bellot, a pistol CZ model 70, caliber 7.65 mm Browning (32 ACP) with common 7.65 mm Browning FMJ Sellier & Bellot ammunition and a revolver S&W Modell 60, barell length 2-1/8', cal. .38 Special with common Sellier&Bellot (FMJ) ammunition. The results of the study have indicated the behavior of GSR particles deposited after a single discharge. The overall time interval of GSR particles deposition and the number of deposited particles with the above mentioned arms and ammunition were established. The results can potentially be used for clarifying the situation at crime scenes and for subsequent interpretation of GSR evidential value in caseworks.     

Unusual sources of Sn in GSR. An experimental study by SEM and IBA

Gunshot Residue (GSR) produced by the discharge of a firearm often provides very useful information in criminal investigations in cases involving the use of firearms. Scanning Electron Microscopy equipped with an Energy Dispersive X-ray Spectrometer (SEM-EDS) is typically used worldwide to visualize micrometric particles constituting GSR and to analyse their elemental composition. The 2017 ASTM Standard guide for gunshot residue analysis by scanning electron microscopy/energy dispersive X-ray spectroscopy specifies that “Particles classified as characteristic of GSR will have one of the following elemental compositions: Lead, antimony, barium; Lead, barium, calcium, silicon, tin”. For the first time, the presence of an additional element, such as Sn, plays a key role in ASTM particle classification. It is known that some ammunitions, used for pistols, revolvers and rifles, contain tin foil discs for sealing the primer mixture into the cup, resulting in GSR particles containing Sn. The authors faced some cases in which Sn was unexpectedly found in GSR particles from a 0.22 Long Rifle derringer and from some 12 gauge shotguns. No tin foil discs are used in rimfire ammunitions and there is no published evidence of tin foil discs in shotshell ammunitions. Following a “case by case” approach, experimental research has been carried out to explain how Sn can be present in GSR particles when the last discharged cartridge also does not contain any Sn either in components and in the explosive charges.Moreover, the use of Particle Induced X-ray Emission (PIXE) showed the capability to overcome overlap ambiguity of Sb and Sn peaks in the X-ray spectra, being a possible key issue in real shooting cases if Sn quantities are below the lower limit of SEM detection, especially when Sb is also present.     

Image analysis of gunshot residue on entry wounds: II – A statistical estimation of firing range

A statistical investigation of the relationship between firing range and the amount and distribution of gunshot residue (GSR), used automated image analysis (IA) to quantify GSR deposit resulting from firings into pig skin, from distances ranging between contact and 45 cm. Overall, for a Ruger .22 semi-automatic rifle using CCI solid point, high velocity ammunition, the total area of GSR deposit on the skin sections decreased in a non-linear fashion with firing range. More specifically there were significant differences in the amount of GSR deposited from shots fired at contact compared with shots fired from distances between 2.5 and 45 cm; and between shots fired from a distance of 20 cm or less, with shots fired at a distance of 30 cm or more. In addition, GSR particles were heavily concentrated in the wound tract only for contact and close range shots at 2.5 cm, while the particle distribution was more uniform between the wound tract and the skin surfaces for shots fired from distances greater than 2.5 cm. Consequently, for future scientific investigations of gunshot fatalities, once standards have been established for the weapon and ammunition type in question, image analysis quantification of GSR deposited in and around the gunshot wound may be capable of providing a reliable, statistical basis for estimating firing range.     

Image analysis of gunshot residue on entry wounds. II--A statistical estimation of firing range.

A statistical investigation of the relationship between firing range and the amount and distribution of gunshot residue (GSR), used automated image analysis (IA) to quantify GSR deposit resulting from firings into pig skin, from distances ranging between contact and 45 cm. Overall, for a Ruger .22 semi-automatic rifle using CCI solid point, high velocity ammunition, the total area of GSR deposit on the skin sections decreased in a non-linear fashion with firing range. More specifically there were significant differences in the amount of GSR deposited from shots fired at contact compared with shots fired from distances between 2.5 and 45 cm; and between shots fired from a distance of 20 cm or less, with shots fired at a distance of 30 cm or more. In addition, GSR particles were heavily concentrated in the wound tract only for contact and close range shots at 2.5 cm, while the particle distribution was more uniform between the wound tract and the skin surfaces for shots fired from distances greater than 2.5 cm. Consequently, for future scientific investigations of gunshot fatalities, once standards have been established for the weapon and ammunition type in question, image analysis quantification of GSR deposited in and around the gunshot wound may be capable of providing a reliable, statistical basis for estimating firing range.     

Evaluation of shooting distance by AFM and FTIR/ATR analysis of GSR

The techniques of atomic force microscopy (AFM) and Fourier transform infrared attenuated total reflectance (FTIR/ATR) spectroscopy are applied to the analysis of gun-shot residue (GSR) to test their ability to determine shooting distance and discrimination of the powder manufacturers. AFM is a nondestructive technique that is capable of characterizing the shapes and size distributions of GSR particles with resolution down to less than a nanometer. This may be useful for estimation of the shooting distance. Our AFM images of GSR show that the size distribution of the particles is inversely proportional to the shooting distance. Discrimination of powder manufacturers is tested by FTIR/ATR investigation of GSR. Identifying the specific compounds in the GSR by FTIR/ATR was not possible because it is a mixture of the debris of several compounds that compose the residue. However, it is shown that the GSR from different cartridges has characteristic FTIR/ATR bands that may be useful in differentiating the powder manufacturers. It appears promising that the development of AFM and FTIR/ATR databases for various powder manufacturers may be useful in analysis and identification of GSR.     

Distribution of gunshot residues--the influence of weapon type

Gunshot residue (GSR) analysis is a frequently used forensic method for investigating shooting events. In this process, GSR-particles are detected on pertinent objects, often the hands of a suspect, with energy dispersive X-ray microanalysis in a scanning electron microscope. The question asked in court is usually the following: "… has or has not a given shot been fired by the suspect (at a certain place and time)?" Unfortunately, this question frequently cannot be answered by the analyst. Only the presence or absence of "characteristic" GSR-particles on the investigated sample can be stated with confidence. All other assumptions are inherently biased by many factors that are usually only known by the culprit or are generally unknown. In order to draw more profound conclusions from GSR analytical results, the dynamics of GSR particles have to be considered, i.e., how these particles reach a suspect. Consequently, the formation of the plume after firing was investigated for eleven different firearms with high speed-video analysis. The results show that a vast scope exists between revolvers - distributing many particles near the shooter - and e.g. shotguns that are quite sealed. These differences between the various weapon types should be considered for interpretation of the results of GSR-analysis.     

Discharge of a Pistol Out a Car Window with the Breech Within the Interior of the Car: Analysis of Gunshot Residue on a Car's Interior Surfaces

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.