PREDICTIVE DEFINITION OF THE SEVERITY OF CLOSED CHEST AND ABDOMINAL TRAUMA CAUSED BY SHOTS FROM 12-GAUGE "FORT-500" RIFLES WITH SHOCK-TRAUMATIC BULLETS OF "TEREN-12P" CARTRIDGES

Objective – the predictive definition of the severity of closed chest and abdominal traumaaccording to the reduced AIS injury scale when firing at various distances from "Fort-500" rifles with shock-traumatic bullets of "Teren-12P" cartridges, depending on theirballistic and energetic characteristics in contact with the human body.Material and methods. To establish the speed of bullets of cartridges "Teren-12P" atvarious distances of the shot in the conditions of KhNSC «Hon. Prof. M. S. BokariusForensic Science Institute» experimental shots from the "Fort-500A" and "Fort-500M1"pump-action guns were conducted. In total, two series of 25 shots were fired from eachgun. The values of the velocities of the bullets at the moment of the firing were measuredusing optoelectronic complexes. The determination of the parameters of the trajectory ofthe flight of bullets was carried out by a combined method by means of calculations basedon the results of experimental shots. The obtained data were processed using licensedMicrosoft Excel spreadsheets.Results. According to the research results, it has been found that the ballistic coefficient of the bullet of the "Teren-12P" cartridge is 47.3 kg/m2. This made it possible to determinethe ranges of minimum and maximum speeds of bullets at different shooting distances.Analysis of the data showed that in some cases the speed of bullets at a distance of 3.5m significantly exceeded the speed range declared by the manufacturer of the cartridges.According to the calculated values, according to the literature data, the graphs of thedistribution of the BC blunt injury criterion and the reduced AIS damage scale wereplotted depending on the distance of the shot for the minimum and maximum bullet speedsof the "Teren-12P" cartridges. According to the graphs, when the "Teren-12P" bulletsare fired at their maximum speeds, there is a 50% risk of a closed chest and abdominalinjury according to AIS -2 – AIS-3 at all distances up to 50 m. Even at minimum bulletspeeds cartridges "Teren-12P" there is a 50% risk of formation of a closed abdominaltrauma according to AIS-2 – AIS-3 with shots from a distance of up to 40 m, and chestinjuries – up to 30 m. Closed trauma to these areas of the body according to AIS-4 can bepredictably caused by shots from a distance of up to 10 m.Conclusions. A significant range of variability in the initial speeds of elastic bullets canlead to an incorrect expert estimate of the firing distance due to the fact that similargunshot wounds can be caused by both a bullet with a high initial speed from a longrange of a shot and a bullet with a low initial speed from a close firing distance. Whenthe "Teren-12P" bullets are fired from "Fort-500" rifles, there is a 50 % risk of a closedchest and abdominal injury according to AIS -2 – AIS-3 at all shooting distances up to50 m. Chest and abdominal injuries according to AIS -4 can be predictably caused whenfired from distances up to 10 m. The results obtained can be used in carrying out complexforensic examinations in cases of the use of "Teren-12P" cartridges.

Side wind and tank speed influence on lateral displacement of the projectile

This article indicates the scope of the formula for determining the magnitude of the lateral displacement of the projectile under the action of crosswind, which is used in the compilation of firing tables. This formula is valid under the following conditions: the force of frontal air resistance to the motion of the projectile is proportional to the its velocity squared; wind speed components are much smaller than the horizontal component of projectile velocity; the projectile velocity projections on the Oy and Oz axes are much smaller than the projections on the Ox axis; the dimensionless coefficient of resistance and the magnitude of the crosswind are constant values. However, in reality, the force of frontal air resistance to the motion of the projectile is only sometimes proportional to the its velocity squared; the projectile velocity projections on the Oz axis may be are much smaller than the projections on the Ox axis and may even be greater than it; the coefficient of resistance is depends on the value of the Makh number, so it can be considered constant only when shooting at short distances. The authors propose a mathematical model for determining the magnitude of the lateral displacement of the projectile under the action of crosswinds. It is believed that the force of the crosswind on the projectile depends on the following factors: air density; the maximum area of the longitudinal section of the projectile; the difference between the value of the lateral component of the wind speed and the speed of the lateral displacement of the projectile, which is raised to a certain power. The magnitude of the values of the lateral displacement of the projectile under the action of the crosswind when shooting at short distances, determined based on the proposed mathematical model, slightly differ from the values of the lateral displacement specified in the firing tables. However, with increasing firing distance, the difference between these values is constantly increasing and the value of the lateral displacement of the projectile determined theoretically is much larger than indicated in the firing tables. In addition, in this research the influence of the tank velocity on the value of the projectile lateral displacement taking into account the action of the crosswind is studied.

How Decomposition and Processing Affect Metallic Particles From a Bullet in Gunshot Defects

A significant portion of forensic anthropological cases involve decomposed or fragmented human skeletal remains. When testifying in a courtroom, often the focus is on trauma interpretation and distinguishing between blunt force trauma, sharp force trauma, or high-velocity projectile trauma. Therefore, forensic anthropologists need to understand how various factors and processes alter human remains during the decomposition process and how those changes affect the interpretation of skeletal trauma patterns. The primary research question addressed in this study is: how does the decomposition and processing of human remains impact the preservation of metallic fragments from gunshot trauma? Fifteen hog (Sus scrofa) crania were shot using hollow-point and full-metal jacketed 9mm ammunition with an 8-foot firing distance. Eight skinless slabs of hog ribs were shot using the same ammunition types as the crania. All hog samples decomposed in an outdoor environment under metal cages to prevent scavenging. Radiographs were taken of each hog sample before and after decomposition and after processing. The results show metallic fragments from the bullet embedding in the soft tissue more frequently than in the hard tissue. Scavengers, mummification, and processing are three critical factors that were found to influence the removal/preservation of metallic fragments during the decomposition process.

The effect of type of firearm and shooting distance on pattern distribution, particle dispersion and amount of gunshot residue

Background Evidence can be defined as the object’s availability and/or information that indicates whether a belief or proposition is true or valid. Gunshot residue (GSR) is an important evidence that can serve many roles in ballistic investigation such as shooting distance, type of firearm and ammunition used in shooting related to GSR. However, due to minimal amount of GSR that can be found in crime scene, suitable methods and technique are required in order to obtain the information from the evidence. This action is also known as evidence recovery. When a firearm is fired, soot or particles are discharged from any opening of the firearm and deposited at the vicinity of point of shooting. Results This study emphasized on the examination of the soot/particles produced and pattern distribution of GSR deposited on white cotton cloth target at varying shooting distances (from 3 to 50 cm) using a video spectral comparator. Pattern distribution and GSR particle density are the main factors in determining the shooting distances in clothing. Principle component analysis (PCA) and hierarchical clustering analysis (HCA) were used to classify firearms; the differences in the GSR pattern distribution are highly recognizable. This study showed that the relationship between the GSR particle dispersion and shooting distance was proportionally linear. The results obtained from the shooting test showed that the diameter of GSR distribution and the amount of residues being deposited from shots fired decreased at distances greater than 21 cm. Conclusion This study will help the investigators in determining the shooting distances and evaluating the firearms used. There is a promising method for examination of GSR pattern on the target material which is also important for firing distance estimation.