In the article «human» and «objective» factors are investigated that influencing on optimization of tactical decisions. Attention is accented on dependence of the got information about the circumstances of crime from the acceptance of correct decisions an investigator. Connection between efficiency of investigation and acceptance of optimal tactical decisions is underlined.The declared problem is not investigational in literature in a sufficient measure. Its separate aspects found the reflection in works: D. А. Solodova, S. Yu. Yakushina and others. Some questions related to optimization of investigation and making decision an investigator we discover in works: R. S. Belkin, V. А. Juravel, V. Е. Konovalova, V. L. Sinchuk, B. V. Shur, V. Yu. Shepitko.The aim of the article is determination of term «optimization», as it applies to tactical decisions in criminalistics, and also consideration of influence of human and objective factors on the acceptance of optimal decisions at investigation of crimes.In the article etymology of term is considered «optimization» and interpretation of its is given as it applies to the acceptance of tactical decisions. The types of mark human and objective factors, stipulating optimization of tactical decisions. The last assists efficiency of tactics of investigation of crimes.At consideration of «human factors» of influencing on optimization decisions, attention applies on «psychological traps» can take place at making decision. Among them such are named, as: anchoring; status quo; irreversible expenses; desired and actual; incorrect formulation; conceit; reinsurance; constancy of memory. Underlined, absence of unambiguity in the brought list over of «objective factors» influencing at choice tactical decision. The different understanding of «tactical risk» is argued, as a factor influencing on an acceptance tactical decisions.The analysis of «human» and «objective» factors influencing on the acceptance of optimal tactical decisions allows drawing conclusion about their interconditionality, in the process of their estimation carried out by an investigator. In practice of investigation, knowledge of the adopted factors can assist being of optimal tactical decisions.