对犯罪现场玻璃上的射击痕迹进行分析，首先要判断射击器具的种类，但因射击器具和弹丸的种类繁多，得以验证的案例较少，故目前还主要依靠办案人员的经验。本文对现场中常见的几种发射器（弹弓、弓弩、气枪、钢珠枪、手枪）进行测速分析，在实验室中模拟对玻璃的射击，制作了191个3.5～5.0 mm厚度平板玻璃的射击样本。实验数据显示，若发射器具发射的弹丸速度范围和使用弹丸种类相对固定，对玻璃产生的破坏程度也相对稳定。本文将玻璃上的射击痕迹形态依破坏程度分成5类，通过对5类痕迹类型的出现概率、组合方式以及痕迹尺寸汇总分析，得出不同射击器具和弹丸的留痕特点。利用对痕迹的精细化分类统计，为现场准确迅速判定射击器具种类提供依据。%ABSTRACT:Damaged glass, out of shooting (or hitting), frequently occurs in crime scene. Although the priority is to ascertain the shooting device’s type when such scene is encountered, yet it is dififcult to accurately conifrm the weapon used because of the prevailing presence of many sorts of shooting devices and bullets (or pellets) to result in very rare veriifcation from actual cases. Therefore, the judgment is always relied on the experience of experts. In this paper, mark evidence on lfat glass was made and investigated from several types of weapon including slingshot, crossbow, air gun, ball gun and pistol. Simulated shooting test was targeted at lfat glass (thick of 3.5-5.0 mm) with the above weapons under different conditions, producing 191 pieces of cracked glass samples. The patterns on the cracked glass, generated by different weapons and projectiles, were carefully examined and compared. Experimental data show that the degree of glass damaging is stable when both the velocity of the projectile and the used pellet matching to some weapon are relatively ifxed. According to the extent of damage, the patterns of marks on glass are divided into ifve categories, with their majority showing combination of two and more categories. Based on the probability of occurrence, category combination and size of the marks, the characteristic of the marks is concluded. Projectiles of stone, steel-ball and gun bullet can be distinguished by the shape of the holes produced on the cracked glass. The caliber of pellet by slingshot, crossbow or ball gun can be judged by the size of the crack. The radial crack by air gun especially tends towards bending. The types of the applied weapons can be deduced by the pattern of the marks. The inlfuential factors on stability of the mark patterns, and the projectile’s track can be ignored but the lfat glass’ characters, such as the size and thickness, must be taken into analyzing the diameter of bullet (or pellet) hole. The discovery here may provide reference for more reifned inquisition about mark evidence on the damaged lfat glass so as to determine the shooting device quick and accurately.
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