The object of the study is the public relations that arise from the use of specialized knowledge in the investigation of illegal handling of weapons, ammunition or explosives. Purpose: to solve a specific scientific problem to develop recommendations for the use of specialized knowledge in the investigation of illegal handling of weapons, ammunition or explosives. Methods: dialectical, system-structural, comparative-legal, sociological, statistical, formal logic. Theoretical and practical results, scientific novelty: identified types of special knowledge used in the investigation of illicit handling of weapons, ammunition or explosives, which are knowledge: in the field of weapons and tracing; forensic photography and photo-video and computer skills; psychology of criminal activity; the process of storage, accounting and issuance of weapons at military facilities, bodies and departments of the Ministry of Internal Affairs, as well as skills in handling weapons; technical research of documents and handwriting; commodity science and outlined the forms of their use for each of the species; defined the concept of optional forms of use of special knowledge which should be understood as activities of knowledgeable persons that contribute to the rapid and complete investigation of criminal offenses, but not recorded in the protocols of investigative (search) actions and annexes to them and other procedural documents; the organizational and tactical bases of involvement of experts for carrying out inspection, search and interrogation at investigation of illegal handling of the weapon, ammunition or explosives, and also algorithms of their activity on each of these investigative (search) actions are developed. Scope of use: in rule-making activity - to improve the normative-legal regulation of the activity of specialists in the investigation of criminal offenses and the procedural order of appointment and examination; in scientific activity - for further research of methods of investigation of illegal handling of weapons, ammunition or explosives at the present stage, as well as methods of conducting certain types of forensic examinations; in the educational process - for the development of programs and guidelines, preparation of textbooks and manuals for the study of disciplines "Criminology", "Criminal Procedure"; in practice - to increase the effectiveness of the investigation of illegal handling of weapons, ammunition or explosives, as well as during the appointment and conduct of certain types of forensic examinations.
