Problem setting: Important and perspective direction of tactical vehicle’ development of criminalistics science in an exposure and receipt of complete, reliable and objective information is research of ideal tracks, mechanism of their forming and factors that influence on their forming. Recent research and publications analysis: In the special literature certain attention was spared to research of negative circumstances in investigation of crimes in labors of next scientists: R.S. Belkin, A.I. Vinberg, A.V. Dulov, V.Yu. Shepitko et al. However, the analysis of the special literary sources allows to assert that value and role of negative circumstances in forming of ideal tracks investigational not enough, separate questions remain debatable. Absent sound researches in relation to the transmitters of negative circumstances, not set forth positions about the value of negative circumstances, features of their exposure, and also possibilities of their use in finishing telling. All of it allows to talk about scientific interest of the put range of problems. Paper objective:The article is devoted to research of psychological nature of ideal tracks’ forming and role of negative circumstances in forming of ideal tracks. Paper main body: Influence of objective and subjective factors is in-process considered on the mechanism of ideal tracks’ forming: – paid attention to research of negative circumstances and their role in forming of ideal tracks;– the question of influence of negative circumstances is investigational on forming of ideal tracks in a conflict situation; – paid attention that influence research of other factors on forming of ideal tracks; – it is investigational essence and value of process of forgetting on forming of ideal tracks. Conclusions of the research: The content of ideal tracks can be exposed only by methods, receptions and rules of communication. An able exposure, estimation and research of negative circumstances, in most cases will assist complete, all-round and objective establishment of truth within the framework of investigation of crimes. Determination of degree of influence of negative circumstances on forming of ideal tracks will assist the correct estimation of the got information, exposure and selection of different sort of errors that arise out of nature of ideal tracks’ forming and to the improvement of tactical arsenal of realization of separate inquisitional (of criminal investigation) actions.