Abstract
The main form of preliminary investigation is an inquiry, which is a starting point for differentiating the choice of forms of preliminary investigation. Evidence of this statement is the official statistics of the number of crimes of investigation, which is carried out both in the complicated form of General inquiry, and in the simplified form-abbreviated inquiry. The vesting of the inquirer procedural autonomy is an important condition for the implementation of its functions, one of the main factors of legality, validity judgments produced by proceedings under the criminal procedure law he is given the opportunity to act independently, at its discretion, to make reasonable findings and conclusions. The investigator, within the framework of his procedural independence, can plan an independent investigation, choose tactics, effective and appropriate methods of investigation aimed at full, rapid disclosure and investigation of criminal acts. The main purpose of this study is to improve the legal framework on which the investigator bases his activities, develop proposals and recommendations to ensure independence in the production of various procedural measures of preliminary investigation.