Innovations in digital communications determined a trend for a sustainable causal link between technological diversity and qualitative changes in the mechanism of extremist crimes. Essentially, the processes of global informatization led to a paradigm shift, and the methods of transforming social behavior based on digital communications and social engineering technologies became some of the key elements in influencing the minds of the objects of extremist indoctrination. Due to this, it is necessary to offer a forensically grounded definition of digital space as a scene where extremist crimes are committed with the purpose of developing recommendation for identifying, capturing and systematizing evidentiary and other forensically relevant information, developing a forensic characteristic and then using it to understand the mechanism of suchlike criminal acts. The methodological basis for the research is the general dialectic method of research cognition. Besides, some general and special research methods were used: systemic-structural, formal-logical, statistical, specific-sociological, analysis and synthesis, induction and deduction, analogy. Data consolidation and modelling were also carried out. According to the author, in order to understand the mechanism of trace formation in the digital environment, it is necessary to identify changes resulting from the electromagnetic interactions between the signal and the environment in which the signal was processed, and to understand what factors influenced the process of electromagnetic interactions. Consequently, in order to identify, capture and establish a link between digital traces and electromagnetic interactions, it is necessary to establish a crossover mutual relationship between a computer device, a digital infrastructure element, as well as an event of interest to the subject of the investigation or an action that has left its reflection. For the extremist crimes committed in the digital space, it is expedient that the crime scene should be interpreted as the place where key criminal extremist actions were committed. Essentially, it is the place where extremist content was uploaded, the information and telecommunication network of the digital space was entered, and the criminal action of extremist nature was then committed, regardless of the place where its consequences happened.