Estimating the shooting distance of a 9-mm Parabellum bullet via ballistic experiment

We demonstrate here how the shooting distance of a 9-mm Parabellum FMJ bullet (115gr) has been estimated via shooting experiments. Such a bullet was found by investigators near a concrete wall, fairly distorted at its tip. The bullet carries no evidence of multiple impact and no evidence of ballistic impact on the wall has been reported. We estimated the impact velocity by comparing the questioned bullet with a set of comparison bullets hitting a wall (rigid target) with different velocities. The shooting distance was recovered from the impact velocity by studying the typical behavior of a manufactured 9 mm bullet weighting 115 g (7.45 g), shot in pistol or a sub-machine gun. The results demonstrated that the questioned bullet was a lost bullet. The shooting distance also helped the investigators, narrowing the range of the estimated positions of the shooter.     

手枪实用射击训练对射击教学的启示

根据现代警察手枪实用射击训练新内容、新方法,提出在新形势下的公安院校射击教学改革的新思路,改革手枪射击教学训练的内容和方法,有针对性的采取灵活多变的教学方法和教学手段,力求公安院校射击教学有所突破。     

浅谈警察的应用射击

公安民警射击训练的实际出发,利用"威氏"射击法,提高命中效果控制紧张情绪,解除心理压力,掌握据抢要领,打牢射 击基础,克服外界影响,提高射击精度。     

影响射击安全的四种心理因素解读

对射击教学训练,管理者通常只注意排除场所、设备等客观可见的危险点,而忽视了人的心理状态对安全具有决定性影响。因此,必须了解参与射击教学活动各类人员的心理状态及其对安全工作的影响,确保射击教学训练安全。     

Police shooting and criminal homicide: The temporal relationship

This study examines the temporal relationship between the incidence of police shooting and the incidence of criminal homicide for New York City between 1971 and 1975. The research finds that there is no temporal relation between the incidence of police shooting and the incidence of criminal homicide and concludes that the very strong and widely supported cross-sectional correlation between police shooting and criminal homicide is spurious, not causal.     

Police shootings. The Metropolitan Dade County experience from 1956 to 1982

Police shootings, or, when law enforcement officers shoot and kill criminal suspects, have been studied in metropolitan Dade County from 1956 to 1982. A total of 194 cases have been studied and analyzed according to age, race, sex, Spanish surname, alcohol and/or drugs detected at autopsy, and prior criminal arrest record of the victim. The reason(s) for the shooting and any agencies involved have also been noted. Finally, an appendix is included that provides guidelines for the forensic pathologist on how to approach a case.     

Distribution of GSR particles in the surroundings of shooting pistol

Several series of experiments were performed to study the distribution of GSR particles in seven directions in the surroundings of shooting firearm (pistol CZ 85 caliber 9 mm Luger). External and internal conditions and two different primer types were used for the shooting experiments. The results showed that maximum number of GSR particles could be found in the right front quadrant at a distance of 2–4 m with respect to the shooting firearm position and shooting direction. GSR particles were even found in distance 10 m from shooting firearm. A significant influence of climatic conditions on GSR distribution was confirmed.     

Predictions put into practice: a quasi-experimental evaluation of Chicago’s predictive policing pilot

Objectives

In 2013, the Chicago Police Department conducted a pilot of a predictive policing program designed to reduce gun violence. The program included development of a Strategic Subjects List (SSL) of people estimated to be at highest risk of gun violence who were then referred to local police commanders for a preventive intervention. The purpose of this study is to identify the impact of the pilot on individual- and city-level gun violence, and to test possible drivers of results.

Methods

The SSL consisted of 426 people estimated to be at highest risk of gun violence. We used ARIMA models to estimate impacts on city-level homicide trends, and propensity score matching to estimate the effects of being placed on the list on five measures related to gun violence. A mediation analysis and interviews with police leadership and COMPSTAT meeting observations help understand what is driving results.

Results

Individuals on the SSL are not more or less likely to become a victim of a homicide or shooting than the comparison group, and this is further supported by city-level analysis. The treated group is more likely to be arrested for a shooting.

Conclusions

It is not clear how the predictions should be used in the field. One potential reason why being placed on the list resulted in an increased chance of being arrested for a shooting is that some officers may have used the list as leads to closing shooting cases. The results provide for a discussion about the future of individual-based predictive policing programs.

     

Averted targeted school killings from 1900-2016

Mass shootings, particularly those that occur on school grounds, often generate intense political debate. Following the 2018 shooting at Marjory Stoneman Douglass High School, questions arose on how to prevent these tragedies. Typically, the response generated from these questions revolves around mental illness, bullying prevention, and gun control. Unfortunately, the views on these topics, especially gun control, are often rooted in a strong belief system which is unwavering. Resultantly, the debate on how to avert these incidents often stops at the debate phase. This study sought to better understand how these events can be prevented by examining targeted school killings from 1900–2016 in which the suspect was stopped before the attack. The analysis revealed that the majority of attacks were prevented by other students reporting the threat of an impending attack to school and law enforcement authorities.     

Characteristics of Backspatter on the Firearm and Shooting Hand—An Experimental Analysis of Close‐range Gunshots

Contact and close‐range gunshot injuries can produce bloodstains on the shooting hand and weapon. In this study, backspatter was analyzed in experimental horizontal pistol shots into blood‐filled sponges. The shooting distances were set between 0 and 45 cm. With increasing shooting distance, there was a significant decrease in the degree of backspatter. Microspatter could be detected on the weapon and shooting hand up to a shooting distance of 40 cm. They were predominantly located on thumb and index finger as well as the radial dorsal aspects of the hand. Fine spray of microspatter combined with elongated droplets in the shape of exclamation marks was found at contact and 2‐cm distance shots. An angular calculation based on the shape of the bloodstains was possible up to a shooting distance of 2 cm. No bloodstains were detected beyond 45 cm.     

Variation of the chemical contents and morphology of gunshot residue in the surroundings of the shooting pistol as a potential contribution to a shooting incidence reconstruction

A study of the chemical contents and sizes of gunshot residue originating from 9×18mm PM ammunition, depositing in the vicinity of the shooting person was performed by means of scanning electron microscopy and energy dispersive X-ray spectrometry. Samples of the residue were collected from targets placed at various distances in the range 0-100cm as well as from hands and clothing of the shooting person. Targets were covered by fragments of white cotton fabric or black bovine leather. In the case of cotton targets microtraces were collected from circles of 5 and 10cm in radius. Results of the examinations in the form of numbers of particles, proportions of their chemical classes and dimensions revealed a dependence on the distance from the gun muzzle, both in the direction of shooting and in the opposite one, i.e., on the shooting person. The parameters describing gunshot residue differed also depending on the kind of the target substrate. The kind of obtained information gives rise to understanding the general rules of the dispersion of gunshot residue in the surroundings of the shooting gun. Thus, it may be utilised in the reconstruction of shooting incidences, especially in establishing the mutual positions of the shooter and other participants of the incident.     

Individual and situational determinants of the use of deadly force: A simulation

The study of police use of deadly force is a complicated issue because of the scarcity of observed high-risk encounters in the field. The present research explores police shooting behavior in both life-threatening and non-life-threatening situations in a simulated environment. The results suggest that officers’ characteristics, such as race and gender, are not associated with officer shooting behavior. The one exception is that officers with less police experience show more restraint than veteran officers in responding to non-life threatening situations. Suspect demographics, such as race, gender, and age, show inconsistent relationships with officer shooting behavior. One consistent finding is that officers who show poor judgment, slow response, or poor marksmanship suffer a high casualty rate in reacting to life-threatening situations involving multiple suspects.     

Assessing the influence of the Columbine shooting on federal sentencing outcomes

School shootings are not a new phenomenon in the United States or internationally. In comparison to other acts of violence experienced by youth, such tragedies are uncommon but garner extensive media attention. The Columbine High School shooting received more attention across a broader range of issues than any other school shooting, with only the Sandy Hook tragedy rivaling it for media attention. In the aftermath of the Columbine shooting, public sentiment regarding violence in schools became a central point of contention that bred fear and panic. Given the embeddedness of judges within the larger community context and the effects of community characteristics on sentencing outcomes, we wondered if the Columbine shooting – via moral panic and community upheaval – might have had an impact on judges imposing criminal sentences. To assess the effect of the Columbine shooting on judicial decision-making outcomes, the current study uses United States Sentencing Commission data from 1998 through 2001. In doing so, it contributes to the extant literature concerning the embeddedness of judges within communities and answers recent call for more research on the temporal context of sentencing disparities.     

A study of dispersion of gunshot residue from a frequently used Serbian ammunition cal. 7.65 mm to support selected aspects of casework in North Macedonia

The subject of this research was the inorganic gunshot residue component collected from shooting patterns obtained on woven cotton cloth using a Pietro Beretta model 70 pistol, cal. 7.65 mm and Serbian ammunition for the following muzzle-to-target distances: 25, 50, 75, 100 and 125 cm. For each distance, three rounds of shooting were performed. Particles were lifted within a 10 cm radius of the projectile entrance and automatically analyzed using a scanning electron microscope coupled with an energy dispersion X-ray spectrometry. The obtained data on the populations of particles were analyzed taking into account their numbers, chemical classes and sizes. The results showed an apparent maximum incidence within all particles containing barium at about 50 cm distance. Also, lead particles revealed a distinct behaviour, being dominant at a 25 cm distance, falling below the other chemical classes, and finally becoming dominant again at 125 cm. The analysis of the frequency of occurrence of particles sorted according to their sizes confirmed that the small particle population is the largest, and their distribution in function of the equivalent circle diameter is exponential-like. The obtained results provided knowledge on the distribution of particles in the vicinity of the tested firearm and ammunition cal. 7.65 mm which generally corroborates with similarly studied GSR distributions obtained for the use of pistols cal. 9 mm. This information, together with the examinations of gunshot damages and other types of residues such as soot or unburned propellant grains may support qualitative inferences on shooting distance estimation, especially in cases, when the firearm and cartridges are not available to perform test shooting. In such cases even roughly estimated shooting distance can be helpful, e.g. for confirming or excluding the possibility of self-inflicted injuries or suicide and infer on the mutual position of the shooting stage actors. An example of casework that illustrates intermediate shooting distance estimation is presented.     

根据霰弹丸分布图形推断射击距离的实验研究

目的 建立推断制式霰弹猎枪射击距离的数学计算公式和方法。方法 选用国产制式12号及16号猎枪,配用1号及3号猎枪弹,以1至12m距离射击实验靶纸,获得霰弹分布图形360例,将图形测量数据与实验距离进行数学理论分析。结果 建立6种不同枪弹种类推断射击距离d的计算公式,分别为12-1型(缩口)ss=-0.2+0.44d;12-1型(无缩口)ss=-0.94+0.63d;12-3型(缩口)ss=-0.59+0.52d;12-3型(无缩口)ss=-0.36+0.34d;16-1型s=-0.37+0.30d;16-3型s=-0.16+0.23d,并用Visual Basic5.0软件编制通用程序汇总软件。结论 本研究建立的方法简单实用,误差较小,可以用于推断制式猎枪的射击距离。     

Fatal impact? The effects of emotional arousal and weapon presence on police officers' memories for a simulated crime

Purpose . (1) To investigate the effects of emotional arousal and weapon presence on the completeness and accuracy of police officers' memories; and (2) to better simulate the experience of witnessing a shooting and providing testimony. Methods . A firearms training simulator was used to present 70 experienced police officers with either a shooting or a domestic dispute scenario containing no weapons. Arousal was measured using both self‐report and physiological indices. Recall for event details was tested after a 10‐minute delay using a structured interview. Identification accuracy was assessed with a photographic line‐up. Results . Self‐report measures confirmed that the shooting induced greater arousal than did the other scenario. Overall, officers' memories for the event were less complete, but more accurate, when they had witnessed the shooting. The recall and line‐up data did not support a weapon focus effect. Conclusions . Police officers' recall performance can be affected both qualitatively and quantitatively by witnessing an arousing event such as a shooting.     

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。     

六四式手枪弹壳发射顺序的研究

目的　研究六四式手枪射击弹壳的排序规律。方法　对已知顺序实弹射击取样 ,显微观察弹壳上发射过程中形成的痕迹 ,通过统计、归纳 ,从中发现与排序有关的痕迹特征 ,及其与发射顺序之间的关系。结果　研究发现 ,因子弹发射顺序不同 ,弹壳上出现的抛壳挺痕的高低 ,弹底边缘压擦痕的有无轻重 ,推弹突笋痕迹的形状位置与发射顺序有关。结论　根据抛壳挺等痕迹的具体形态 ,及变化特点 ,可判断出六四手枪弹壳的发射顺序。     

Administrative interventions on police shooting discretion: An empirical examination

In August, 1972, the New York City Police Department promulgated administrative shooting guidelines and shooting incident review procedures far more restrictive than former statutory “defense of life” and “fleeing felon” justifications for police shooting. Using a data base that includes all reported New York City police firearms discharges and serious assaults on police between 1971 and 1975, this article examines the effects of the new guidelines and procedures on shooting frequencies, patterns, and consequences.Great decreases in “fleeing felon” shootings, “warning shots,” and shooting-opponent injuries and deaths were found to be associated with the new rules. This change also appeared to have a favorable effect on line-of-duty officer deaths and serious injuries. The implications of these findings are discussed.