Approximately 70-75% Of Homicides Are Committed With 805298

Approximately 70-75% of homicides are committed with firearms

Homicide statistics reveal that approximately 70% to 75% of killings involve the use of firearms, underscoring the significant role that guns play in violent crimes. Understanding the manufacturing of handguns, the science of ballistics, and the forensic analysis of firearm-related injuries is essential for criminal investigations and legal proceedings. This paper addresses the manufacturing process of handguns, the purpose and function of rifling within the barrel, the differences between revolvers and semiautomatic pistols, and various forensic considerations such as determining handgun caliber, class versus individual characteristics, and wound analysis. Additionally, it explores the forensic identification of gunshot range, including characteristics indicative of different shooting distances and the types of evidence collected at a crime scene involving firearms.

Part 1: Manufacturing and Components of Handguns

The manufacturing of handguns is a complex process that involves precision engineering to ensure safety, reliability, and performance. A critical component of a handgun is its barrel, which guides the projectile during firing. The bore of the barrel—the interior channel through which bullets travel—is machined with high precision to ensure consistent accuracy. The bore’s dimensions are determined based on the firearm's caliber, which is a measure of the internal diameter of the barrel.

Rifling is present in the bore of most modern firearms to improve accuracy and stability of the projectile. Rifling consists of spiral grooves cut or formed into the bore's interior surface. The primary purpose of rifling is to impart a stabilizing spin to the bullet as it travels down the barrel, which minimizes yaw and tumbling in flight. This stabilization enhances accuracy and consistency, especially at longer ranges. Without rifling, projectiles would be less stable in flight, resulting in decreased precision.

In comparing revolvers and semiautomatic handguns, several distinctions emerge. Revolvers utilize a rotating cylinder containing multiple chambers, each holding a single cartridge. When the trigger is pulled, the cylinder advances to align a chamber with the barrel, allowing a shot to be fired. Revolvers are praised for their mechanical simplicity and reliability but tend to have a slower rate of fire and limited ammunition capacity.

Semiautomatic handguns, on the other hand, automate the ejection of spent cartridges and chambering of new rounds through the cycling of the firearm's action, typically via the energy of the fired cartridge. They generally offer higher ammunition capacity and faster firing rates. However, semiautomatic pistols can be more mechanically complex, which may result in increased maintenance requirements but also greater versatility in design and features.

Determining Handgun Caliber and Ballistics Concepts

The caliber of a handgun is determined by measuring the internal diameter of the barrel or the diameter of the projectile it fires, expressed in inches or millimeters. For example, a 9mm pistol fires a projectile measuring approximately 9 millimeters in diameter. This measurement is critical for matching ammunition to firearms and for forensic analysis.

Within ballistic forensic science, a clear understanding of the terms bullet, shell casing, and projectile is necessary. The bullet is the conical or rounded metal projectile propelled from the firearm. The shell casing is the metal container that holds the gunpowder, primer, and the bullet, which ejects after firing. The projectile refers to the actual part that leaves the barrel and impacts the target.

For forensic examination, class characteristics include general features such as caliber and rifling pattern, which can be shared among many firearms. Individual characteristics are unique markings on bullets or shell casings resulting from manufacturing defects, wear, or specific gun use. For example, tool marks left on the casing's extractor or ejector area can serve as individual identifiers.

Gunshot Wounds: Perforating vs. Penetrating & Entrance vs. Exit

A perforating gunshot wound occurs when the projectile passes through the body, creating both an entrance and an exit wound. Conversely, a penetrating wound involves a projectile that remains lodged inside the body, creating only an entrance wound.

Entrance wounds typically display a more defined, often round or oval opening with characteristics such as stippling (powder residue) if close-range firing occurs. Exit wounds tend to be larger, with irregular or stellate edges, and usually exhibit less stippling due to the bullet's passage through tissue, causing more tissue disruption.

Part 2: Muzzle-to-Target Distance & Crime Scene Evidence

Determining the distance between the firearm muzzle and the target relies on analyzing physical evidence at the scene. The four primary ranges include contact, near contact, close range, medium range, and distant range. Each range presents distinctive features:

• Contact Range: The firearm is pressed against or nearly against the skin or clothing. Evidence includes a stippling or powder tattooing up to the impact site, a uniform gunshot residue deposit, and possibly a muzzle imprint or soot deposit on the skin or clothing.
• Near Contact Range: The muzzle is within a few centimeters of the target. Similar to contact range, but with less soot and stippling, the shot may create a distinctive stippling pattern and powder residues.
• Close Range: The muzzle is a few centimeters to about 30 centimeters from the target. Characteristic features include stippling, powder tattooing, and unburned or partially burned gunpowder particles. The wound may also exhibit a soot deposit that radiates outward.
• Medium Range: The firearm is several centimeters to a meter away. Powder stippling and soot are generally absent, but the entrance wound may display a small beveling or abrasion. Gunshot residue may be present on the skin or clothing at a distance.
• Distant Range: The firearm is more than a meter away from the target. The wound generally lacks stippling or soot, with a clean entrance wound and no residual gunshot residue markings.

At a crime scene, investigators document evidence such as gunshot residue patterns, stippling, soot, and the nature of the wound. They also examine the firearm itself for markings, caliber, ammunition type, and other forensic evidence. Collecting shell casings, witness statements, and photographs forms part of comprehensive scene analysis.

Conclusion

Understanding the manufacturing, ballistics, and forensic aspects of firearms is integral to criminal investigations. Recognizing the differences between revolvers and semiautomatic pistols aids in identification and reconstruction of shooting incidents. Accurate determination of muzzle-to-target distance and detailed evidence collection enhances investigative outcomes. As firearm violence remains prevalent, ongoing research and forensic advancements are vital to improving law enforcement and judicial responses to firearm-related homicides.

References

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• Hueske, J. (2017). Gunshot Wound Injuries: Pathology, Evidence, and Forensic Science. Elsevier.
• Kirk, T. (2015). Forensic Ballistics: The Investigation of Gunshot Wounds and Firearm Evidence. CRC Press.
• Tischler, S. (2018). Forensic Investigation of Firearm-Related Homicides. Journal of Forensic Sciences, 63(5), 1443-1450.
• Hodgson, P. (2019). Forensic Aspects of Firearms and Firearm Evidence. CRC Press.
• Marcher, P. (2016). Ballistics: Fundamentals and Applications. Wiley.
• Amir, J. (2020). Crime Scene Investigation of Gunshot Wounds. Forensic Science Review, 32(2), 45-66.
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• National Institute of Justice. (2020). Firearms and Ballistics Evidence. U.S. Department of Justice.