An evaluation of measurement uncertainty of trajectory angles using a 3D laser scanner

Measuring trajectory angles of bullet defects at a crime scene is an important part of crime scene investigation as these angles can be used for shooting incident reconstructions. The Washington State Patrol Crime Scene Response Team (WSP CSRT) had a desire to report and use measured trajectory angles. To report quantitative measurements, a statement of uncertainty for the measurement must also be reported due to an accreditation requirement through the ANSI National Accreditation Board (ANAB), through which the WSP CSRT is accredited. This evaluation examined the measurement uncertainty of the 3D laser scanning method that the WSP CSRT utilizes for measuring the vertical and azimuth angles from trajectory rods fitted to bullet defects. Three studies were performed which examined the variation of vertical and azimuth angle measurements from trajectory rods on flat surfaces, the variation of azimuth angle measurements from a trajectory rod on a curved surface, and a traceability study with known vertical and azimuth angle measurements. Seven common substrates were selected as target materials and were shot with 9 mm Luger and 0.45 Auto caliber bullets. A vehicle with one bullet defect was utilized for the curved surface study. The WSP's current fleet of Trimble X7 3D laser scanners, the WSP Criminal Investigation Division (CID) Detectives who operate these scanners, and the Forensic Scientists responsible for trajectory rod placement and angle measurements were utilized. An overall measurement uncertainty of +/− 2.6 degrees at an approximate 95% confidence interval was determined for all trajectory angles measured from trajectory rods.     

The media’s coverage of mass public shootings in America: fifty years of newsworthiness

This study uses a media distortion analysis to examine the New York Times coverage of mass public shooting incidents occurring in the United States from 1966 to 2016. A comparison between media coverage and actual incidents is used to identify the characteristics influencing the newsworthiness of mass public shootings. This work expands the breadth and depth of media and mass public shooting research, strengthening the validity of previous findings, and identifying new characteristics influencing newsworthiness. Findings indicate significant predictors of newsworthiness include higher casualties and injuries, as well as perpetrators that are young, Middle Eastern, and ideologically motivated. School shootings are more likely to receive any coverage, and all non-workplace shootings receive salient levels of coverage. An incident is also more likely to receive any coverage if a combination of weapons is used. These findings have important implications for public knowledge and perceptions of mass public shootings.     

浅谈在职干警的射击培训

对基层干警进行应用射击培训，是当前治安形势的要求。面向基层，面向实战是当前是公安教育改革的方向。如何提高在职干警的射击水平，更好地防范和打击犯罪，是本文重点探讨的问题。     

试析警察射击教学中的心理素质训练

射击是公安警务人员必须掌握的一门基本警务技能。心理素质的好坏 ,直接关系到警务人员射击技术水平及其综合素质的提高。因此 ,在院校射击教学中加大心理素质训练力度 ,具有现实必要性。心理素质训练的一般方法主要有 :放松训练、集中注意力训练、表象技能训练、模拟训练、情景刺激训练和情绪体验。     

试论利用多媒体场景互动射击训练

利用“多媒体场景互动射击训练系统”对受训者进行训练,不仅可以有效地提高受训者警务实战技能水平,而且能提高公安执法实践当中集法律、战术、技术和心理学应用等四位一体的综合执法战斗水平。     

A configurational analysis of 44 US mass shootings: 1975–2015

This study identifies the conditions under which civilian shooter events in the United States become mass episodes of killing. Hitherto, researchers have examined many individual-level variables associated with mass shootings including personal deprivation, family problems, mental illness, among others. Apart from a handful of quantitative studies, scholars have yet to provide a comparative scope to the multiplicity of factors that are influential in bringing about a mass murder. Adopting fuzzy-set qualitative comparative analysis, this study analyses (n = 44) civilian acts of violence that took place from 1975 to 2015 in which some shootings resulted in few deaths and others turned into mass bouts of killing. Empirical results reveal that no variables on their own are sufficient or necessary in accounting for the outcome of a mass shooting. Rather, configurations of causal conditions provide sufficient pathways and new insight into the particular circumstances under which a mass shooting is apt to take place in. The most salient of configurations tell us that mass shootings are prominently influenced by the combination of severe/multiple mental illnesses, a large number/high-powered guns and weak state gun law legislation. Another pathway reveals that mass shootings are also influenced by the interaction of radical ideology, severe/multiple mental illnesses, and high-state level gun ownership.     

七七式手枪弹头发射顺序的规律性研究

目的研究总结七七式手枪射击弹头的排序。方法对已知顺序的实弹射击取样,显微观察弹头上连续射击过程中形成的痕迹,通过统计、归纳,从中发现各痕迹与射击顺序之间的关系。结果根据弹头上的磕碰痕迹、顶压痕迹的出现规律判断出七七式手枪发射子弹的顺序。     

加强手枪射击教学实用性训练 提高学员的实战能力

目前,射击虽作为全国公安院校学员的必修课,大部分的射击教学都是以基础知识和基本技能训练为主,并不注重实战能力的训练,而我们培养的学员今后要使用手中的武器去与犯罪分子进行殊死搏斗。因此,提高学员的实战能力就成为我们手枪射击教师的当务之急。提高学员的实战能力,就要加强近距离快速射击训练;利用地形地物的射击训练;多目标选择性的射击训练;快速重新装弹训练;反应性射击训练。     

一例枪支走火案件的分析检验步骤和方法

在实践中,我们经常会碰到由于枪支走火、跳弹等致人死亡的意外事件,对此类案件的分析、检验往往有一定的难度,特别相隔较长一段时间后,许多信息随着时间的流逝而不能加以充分利用时。所以对此类案件该如何利用有限的资源信息以准确认性,这是非常关键的问题。本文结合一具体案例,提出对此类案件进行分析检验的步骤和方法。     

基于协同机理的77式手枪射击训练探索

为适应公安院校射击课程的教学改革,尽快使学生适应77式手枪的打法和要求,实现在规定的时间内完成首发命中,连续打完5发子弹的要求,提高学生训练水平和教学成绩。文章基于64式手枪与77式手枪在射击过程中的差异分析,对如何使用77式手枪进行射击基础训练、如何掌握射击的规范性动作,以及77式手枪训练中应注意的问题进行了研究。