When investigating crimes involving firearms, the correct legal definition of the term «firearm» is of paramount importance. The provisions of the Criminal Code of the Russian Federation (Articles 222-226) establish criminal liability for unlawful acts related to this type of weapon, including its illegal acquisition, storage, manufacture, sale—as well as theft and careless storage [1]. However, the law does not define what exactly constitutes a firearm.

Despite the diversity of scientific interpretations of the term «weapon,» the fundamental principle of its operation has remained consistent throughout the history of industrial production. The operation of any firearm is based on a single physical mechanism: the projectile is propelled by the energy of expanding powder gases resulting from the detonation of gunpowder or its modern equivalents. In this study, we will conduct a comparative analysis of existing definitions of firearms, formulate substantiated conclusions, and offer practical recommendations based on the data obtained. The legal definition of firearms is enshrined in the Federal Law «On Weapons» (Article 1, Part 1 of Article 2) [2].

A significant addition to the statutory definition is contained in Resolution No. 5 of the Plenum of the Supreme Court of the Russian Federation of March 12, 2002, «On judicial practice in cases of theft, extortion, and illegal trafficking of weapons, ammunition, explosives, and explosive devices.» The document explains the key criteria for classifying items as firearms in criminal cases, including [3]:

— the presence of a barrel or an element that performs its functions;

— the ability to generate sufficient gas pressure to propel a projectile;

— structural strength, ensuring the possibility of repeated use;

— sufficient destructive power of the projectile.

These clarifications play an important role in law enforcement practice, helping to avoid ambiguous interpretations when classifying crimes.

The law must contain a set of key elements, the presence and interrelationship of which form the basis for such classification. If a specific firearm lacks any of these features, but is designed to fire projectiles at a distance, this precludes its classification as a different type of weapon.

Effective and comprehensive investigation of firearms-related crimes requires not only a clear definition of the term «firearm» but also a comprehensive and detailed classification system.

In forensic classification, adhering to strict logical principles of systematization is essential. A key methodological postulate is that the basis for classification should be based not on the empirical characteristics of the objects themselves, but on the scope of their concepts—that is, on the set of attributes that determine the object’s place in the classification system.

Terms used to designate forensic categories must meet two fundamental requirements:

Hierarchical relationship—each element (subordinate concept) must be unambiguously assigned to a specific classification system within a given generic concept. This ensures the integrity and consistency of the system.

Differentiating uniqueness – an element must possess a specific characteristic that clearly distinguishes it from other elements within the same classification group. This characteristic serves as a demarcation criterion and prevents category overlap.

Compliance with these requirements allows for the creation of a logically coherent, practically applicable classification that minimizes the risk of errors in forensic analysis and data interpretation [7, p. 135].

A comprehensive approach to studying forensic objects involves a multifaceted analysis of multiple objects or phenomena encompassed by the relevant forensic concept. This approach requires examining the object of study from various perspectives: functional, structural, dynamic, and causal.

When conducting classification studies, it is unacceptable to limit oneself to identifying groups based on a single characteristic, as this leads to simplification and distortion of the real picture. Instead, it is necessary to develop multi-level classification systems that take into account the entire spectrum of characteristics of real-world objects:

— design features;

— functional properties;

— mechanism of interaction with the environment;

— traces of impact and their representation;

— legal and procedural aspects.

Classification criteria must meet the following requirements:

— practical applicability – ensure the effective use of forensic methods in investigations;

— information content – ​​provide comprehensive data for the identification and comparison of objects;

— reproducibility – enable the same results to be obtained in repeated studies;

— Adaptability – allowing for the inclusion of new categories as new types of crimes or technologies emerge.

As N. N. Egorov emphasizes, the concept of a «purely» forensic classification of crimes is methodologically untenable. This is due to the close relationship between forensic science and other legal disciplines, primarily criminal law.

Any classification of crimes inevitably relies on:

— the conceptual apparatus of criminal law (compound, categories of crimes, qualifying features);

— legal criteria for differentiation (object of offense, form of guilt, degree of public danger);

— the regulatory framework (articles of the Criminal Code of the Russian Federation defining the features of specific crimes).

At the same time, when constructing classifications, it is necessary to consider forensic medical aspects, which play a significant role in the investigation of a number of crimes. These include:

— the nature and mechanism of bodily injuries;

— establishing a cause-and-effect relationship between the actions of the offender and the ensuing consequences;

— determining the age and sequence of injuries;

— identifying the crime weapon based on the nature of the injuries.

Thus, an effective crime classification must be interdisciplinary, integrating approaches from criminal law, forensic science, and forensic medicine [6, p. 310].

Forensic crime classification is not simply a formal systematization, but a scientifically based structure that unites criminal acts based on their forensic and criminal law characteristics. Its key goal is to improve the effectiveness of solving cognitive and practical problems within the framework of forensic examination and investigative activities.

Such classification allows:

— to optimize the choice of investigative methods;

— to systematize the evidence base;

— to predict possible scenarios for the commission of similar crimes;

— to standardize approaches to the analysis of traces and material evidence.

The objects of forensic classification include:

— Individual illegal acts as elements of criminal activity.

— Groups of crimes with similar forensic characteristics.

— Categories of socially dangerous acts enshrined in criminal law.

— Groups of crimes identified based on forensic criteria (method of commission, traces, tools used, etc.).

As criminologists V.V. Biryukov and M.A. Gorbunova note, the most comprehensive classification system is based on an integrated approach that combines:

— criminal law criteria (elements of the crime, classification);

— forensic characteristics (traces, methods of commission);

— technical characteristics of the crime weapons (for firearms – caliber, loading type, mechanism of action, etc.);

— forensic data (nature of injuries, firing range, etc.). This system formed the basis for the modern classification of firearms, necessary for the effective investigation of firearm-related crimes [4, 5].

Firearm Classification

1. By intended purpose:

Combat weapons – intended for combat operations:

— military;

— special.

Service weapons – (security agencies, environmental services, etc.):

— short-barreled, smoothbore, and rifled with a projectile energy of up to 300 J;

— long-barreled smoothbore;

— restrictions: no burst firing, magazine capacity ≤ 10 rounds, bullets without hard cores.

Civilian weapons – for self-defense, hunting, and sport.

2. By bore design:

— Rifled – with helical rifling (usually 4-6 grooves, with a right or left inclination).

— Smoothbore – without rifling, with variations in bore shape:

— cylindrical (uniform diameter);

— semi-choke and full choke (narrowing at the muzzle to concentrate the pellets).

Combined – a combination of smoothbore and rifled barrels (double-barreled and triple-barreled systems).

3. By barrel length:

— short-barreled (up to 20 cm – revolvers, pistols);

— medium-barreled (20–40 cm – submachine guns, assault rifles);

— long-barreled (over 40 cm – shotguns, rifles, carbines).

4. By caliber:

— small-bore (up to and including 6.5 mm);

— normal-caliber (6.5–9 mm);

— large-caliber (over 9 mm).

5. By loading method:

— muzzle-loading (ramrod);

— breech-loading.

6. By type of cartridges used:

— centerfire (primer in the center of the case);

— rimfire (primer composition in the case flange);

— rimfire (pin cartridges).

7. By number of rounds:

— single-shot;

— multiple-shot.

8. By loading mechanism operation:

— non-automatic (manual loading);

— semi-automatic (automatic preparation for the next shot, but a second trigger pull is required);

— automatic (continuous firing without a second trigger pull);

— combined (single-shot and burst modes).

9. By manufacturing method:

— factory (standard, manufactured according to technical regulations);

— Homemade (manufactured without adhering to standards, including modified factory-made weapons);

— Handicraft (manufactured by qualified craftsmen using technological procedures).

10. By firing system design:

— Striker-fired;

— Hammer-fired;

— Bolt-action.

Homemade weapons can be made from readily available materials or by modifying legal devices (starting pistols, flares, etc.). To qualify as firearms, they must have the following:

— the presence of structural elements (barrel, locking device, igniter);

— the ability to cause actual harm (sufficient damaging force).

Atypical weapons are devices that do not fall into standard categories but possess the characteristics of firearms (e.g., camouflaged weapons). In recent years, such weapons have increasingly been mass-produced, especially for the needs of special services.

Key challenges in forensic analysis:

— variability of marks on bullets and cartridge cases even when fired from the same weapon (due to barrel wear, ammunition quality);

— lack of uniform marking standards for homemade weapons;

— use of non-standard materials and manufacturing technologies.

For accurate identification, the following are used:

— physical analysis (inspection of structural elements);

— microscopic examination of traces on bullets/casings;

— chemical analysis of powder deposits;

— comparative ballistic tests.

A clear definition of the term «firearm» and a multi-level classification are critical for:

— correct classification of crimes;

— selection of expert methods;

— building an evidence base;

— preventing new crimes through trend analysis.

The integration of criminal law, forensic, and technical criteria into a single system allows for the creation of a flexible and effective tool for investigating crimes involving firearms [9, p. 67].

Currently, the country faces a high level of illegal arms trafficking among its citizens. This phenomenon is caused by a combination of factors, including frequent armed conflicts, the formation of illegal armed groups, society’s vulnerability to criminal threats, and the ineffectiveness of existing government systems for identifying and monitoring the illegal arms trade.

According to expert estimates, approximately 1.5 million weapons are currently in Russia owned by citizens without proper registration.

An analysis of judicial practice allows us to formulate the following conclusions:

A clear classification of weapons is the basis for proper qualification. Without determining the type, method of production, and destructive power, it is impossible to correctly apply the provisions of the Russian Criminal Code.

An examination is a key element of proof. Ballistic, trace evidence, and chemical examinations allow us to:

— establish the weapon’s fitness for fire;

— identify the weapon by traces on bullets/casings;

— determine the firing distance and the mechanism of damage.

Considering the victim’s subjective perception is important when qualifying threats and robbery.

An interdisciplinary approach (criminal law + forensic science + forensic medicine) increases the reliability of conclusions.

Recommendations for improving practice:

— update forensic examination methods in light of new technologies (3D printing, composite materials);

— unification of approaches to assessing homemade and concealed weapons;

— improving the qualifications of experts and investigators in ballistics and forensic science;

— implementation of digital databases for recording weapon traces and comparing evidence.

Thus, forensic classification not only systematizes knowledge about weapons but also directly influences law enforcement practices: from the correct classification of an act to the choice of investigative methods and the formation of an evidence base.

To summarize, several key conclusions can be drawn.

First, for investigating crimes involving the use of firearms, it is crucial to have a clear understanding of what exactly is meant by the term «firearm.» Legislation, in particular the Federal Law «On Weapons,» provides a general definition, and the resolution of the Plenum of the Supreme Court of the Russian Federation clarifies and expands it. However, in practice, this is not enough – a well-designed classification system is also necessary.

Second, it is important to distinguish between homemade and factory-made weapons. A homemade weapon is considered a firearm only if it possesses lethal force, whereas a factory-made weapon requires only three basic structural elements, even if they are damaged or unusable. This is a fundamental point that often arises in professional practice.

Thirdly, firearm classification must be multifaceted. A weapon cannot be classified solely by a single characteristic, such as barrel length or caliber.