The article analyzes the peculiarities of the participation of specialists in the pre-trial investigation of war crimes committed by the armed formations of the aggressor state on the territory of Ukraine. The significance of the involvement of persons with special knowledge in such investigative (search) actions as inspection of the scene, questioning of suspects, victims and witnesses was emphasized. The purpose of the article is to identify the forms of participation of specialists in the investigation of the specified crimes, the analysis of their functional capabilities, as well as the argumentation of the expediency of involvement in cases that require an interdisciplinary approach. It is substantiated that the help of specialists in the fields of criminology, ecology, forensic medicine, IT, etc., is an important condition for the effective detection, recording and evaluation of evidence in the complex conditions of a military conflict. Emphasis is placed on the growing role of digital information and cooperation with civil society in the process of forming the evidence base, as well as on the need for coordination of investigators with rescue and environmental services when documenting war crimes, in particular ecocide.