Forensics. Identification of weapons by bullets and cartridges. Establishing the distance and direction of the shot, the location of the shooter (the most important)

Lecture notes, cheat sheets
Free library / Directory / Lecture notes, cheat sheets

Forensics. Identification of weapons by bullets and cartridges. Establishing the distance and direction of the shot, the location of the shooter (the most important)

Lecture notes, cheat sheets

Directory / Lecture notes, cheat sheets

Comments on the article

Table of contents (expand)

27. IDENTIFICATION OF WEAPONS BY BULLETS AND CASES. SETTING THE DISTANCE AND DIRECTION OF THE SHOT, THE LOCATION OF THE SHOOTER

Firearm identification is the most common forensic ballistics test and can be done from bullets and shell casings.

When firing a shot, the striker strikes the primer of the cartridge. From the impact, as a result of the explosive decomposition of the capsule composition, fire is formed, which penetrates to the powder charge. Gunpowder ignites. When it burns, a large amount of powder gases are formed, which put pressure on the projectile and push it out of the sleeve into the bore.

In a rifled weapon, the bullet passes through the bore, tightly adhering to its walls. Due to this, traces of the relief of the walls of the bore are formed on its shell. In these traces, during the study, one can detect the fields of rifling and the rifling themselves, and other small irregularities. Since the number, direction, steepness and width of rifling for different models of weapons are usually different, then by the marks on the bullet, in combination with data on the caliber, shape, material of the bullet, it is possible to determine from which model of the weapon this bullet was fired.

Based on the marks on the bullet, identification is also possible, i.e., establishing that the bullet was fired from this particular weapon, since, in addition to rifling and fields, it also displays small features of the relief of the walls of the bore, which are inherent in this instance of the barrel. It is also possible to identify weapons by spent cartridges. Traces are formed when loading, firing and unloading weapons. These marks are formed from the contact of the cartridge case with parts of the weapon.

The most valuable are the traces:

1) striker (drummer) on the primer;

2) ejector in the groove or on the edge of the sleeve cap;

3) reflector;

4) chamber on the case body.

For identification by the cartridge case, it is necessary to find features in the traces on the cartridge case from the parts of the weapon that are individual for a given instance of the weapon. These are the features of the microrelief of the surfaces of these parts.

To identify a weapon by a fired bullet, it is necessary to detect in the traces on it a reflection of the individual features of the relief of the walls of the bore.

Identification of weapons from marks on bullets and shell casings seized at the crime scene is usually done by comparing these marks with marks on bullets and shell casings specially fired from weapons found at the crime scene. Such bullets and shells are called experimental.

Shot distance is the distance in a straight line between the muzzle of the weapon and the entrance hole on the obstacle. It is possible to determine the shot distance at close shooting distances. For this purpose, traces of a close shot are used, which include traces of mechanical destruction of an obstacle by powder gases, traces of thermal effects - scorching or burning, deposition of shot soot, deposition of gunpowder residues, etc. The distance at which traces of a close shot are formed depends on a number of factors, related to the type and condition of the weapon and the ammunition used.

Authors: Aleinikov A.G., Salova E.E.

<< Back: Forensic ballistics. The concept and classification of firearms and ammunition

>> Forward: Forensic investigation of explosive devices, explosives and explosion traces

We recommend interesting articles Section Lecture notes, cheat sheets:

▪ World economy. Lecture notes

▪ Pedagogy. Crib

▪ Land law. Crib

See other articles Section Lecture notes, cheat sheets.

Read and write useful comments on this article.

<< Back

Latest news of science and technology, new electronics:

The existence of an entropy rule for quantum entanglement has been proven 09.05.2024

Quantum mechanics continues to amaze us with its mysterious phenomena and unexpected discoveries. Recently, Bartosz Regula from the RIKEN Center for Quantum Computing and Ludovico Lamy from the University of Amsterdam presented a new discovery that concerns quantum entanglement and its relation to entropy. Quantum entanglement plays an important role in modern quantum information science and technology. However, the complexity of its structure makes understanding and managing it challenging. Regulus and Lamy's discovery shows that quantum entanglement follows an entropy rule similar to that for classical systems. This discovery opens new perspectives in the field of quantum information science and technology, deepening our understanding of quantum entanglement and its connection to thermodynamics. The results of the study indicate the possibility of reversibility of entanglement transformations, which could greatly simplify their use in various quantum technologies. Opening a new rule ... >>

Mini air conditioner Sony Reon Pocket 5 09.05.2024

Summer is a time for relaxation and travel, but often the heat can turn this time into an unbearable torment. Meet a new product from Sony - the Reon Pocket 5 mini-air conditioner, which promises to make summer more comfortable for its users. Sony has introduced a unique device - the Reon Pocket 5 mini-conditioner, which provides body cooling on hot days. With it, users can enjoy coolness anytime, anywhere by simply wearing it around their neck. This mini air conditioner is equipped with automatic adjustment of operating modes, as well as temperature and humidity sensors. Thanks to innovative technologies, Reon Pocket 5 adjusts its operation depending on the user's activity and environmental conditions. Users can easily adjust the temperature using a dedicated mobile app connected via Bluetooth. Additionally, specially designed T-shirts and shorts are available for convenience, to which a mini air conditioner can be attached. The device can oh ... >>

Energy from space for Starship 08.05.2024

Producing solar energy in space is becoming more feasible with the advent of new technologies and the development of space programs. The head of the startup Virtus Solis shared his vision of using SpaceX's Starship to create orbital power plants capable of powering the Earth. Startup Virtus Solis has unveiled an ambitious project to create orbital power plants using SpaceX's Starship. This idea could significantly change the field of solar energy production, making it more accessible and cheaper. The core of the startup's plan is to reduce the cost of launching satellites into space using Starship. This technological breakthrough is expected to make solar energy production in space more competitive with traditional energy sources. Virtual Solis plans to build large photovoltaic panels in orbit, using Starship to deliver the necessary equipment. However, one of the key challenges ... >>

Random news from the Archive

Developed a chemical compound that mimics the behavior of the cell 04.04.2017

Scientists from Harvard have developed a unique compound that mimics the behavior of a cell. The chemical system itself is transformed from a mixture into a structure, it is able to grow and move.

Despite the fact that the compound repeats the behavior of the cell, its main component is a unique molecule that is unusual for living organisms. The researchers used in their study a mixture of 2-hydroxypropyl methacrylate, which also included ruthenium and a light-sensitive metal. As a result, molecules not only react to light, but can also form long chains with each other - polymers. One end of the chain attracts water, while the other repels it.

The behavior of a unique chemical compound truly mimics the processes in a cell. The interaction of polymers with water leads to the formation of spherical vesicles, so similar in size to natural cells. New matter can spontaneously form and make copies of chains. The presence of photosensitive metals contributes to the fact that cells reach for light and prefer to settle near its sources.

Other interesting news:

▪ Green energy is on the rise

▪ Biostar J3160MD motherboard

▪ Bionic eye

▪ The ozone hole must disappear

▪ Nanoparticles hit the heart

News feed of science and technology, new electronics

Interesting materials of the Free Technical Library:

▪ section of the site Microcontrollers. Article selection

▪ cybernetics article. History and essence of scientific discovery

▪ article When did the yellow jersey appear in cycling? Detailed answer

▪ article Hogweed ordinary. Legends, cultivation, methods of application

▪ article Mercerization of paper fabric and yarn. Simple recipes and tips

▪ article Birth of an egg. Focus Secret

Leave your comment on this article:

All languages of this page

Home page | Library | Articles | Website map | Site Reviews