It's been a relatively short period of time since the adoption of the new regulations in the realm of special investigative activity, the period in which the law enforcement authorities vested with plenary powers in the field of combating the crimes have acquired a solid experience in applying the law provisions in this segment. The experience in question is characterized by positive moments and also is imposed by certain negative aspects. The positive side is the active use of results of special investigative activity in the probative process of criminal cases, and the negative part marks on the lack of confidence to these results in the practice of criminal procedure. More than that, legal rules on special investigative activities contain multiple contradictions, ambiguities and gaps, which affect their proper and uniform application. This article is focused on current problems related to classification and conditions of special investigations measures which analysis allowed us to identify the premises, legalities and mechanism of specialized knowledge consolidation in the field of special investigative activity.