The development of the institute of petitions and complaints and the lawyer's investigation are two competing directions in the development of adversarial principles in pre-trial proceedings

The norms of international law and its principles, ratified by Russia, should be included in the criminal procedure legislation. This requirement is fixed in Part 3 of Article 1 of the Code of Criminal Procedure of the Russian Federation. In this regard, this article is aimed at solving the problem caused by the difficulty of implementing the adversarial principle in pre-trial proceedings. The complex consideration of the problem was carried out using methodological approaches: the exclusion method, the analytical method, the method of analysis and synthesis. The article presents three legal positions of scientists and practitioners on the possibility of implementing the principle of competition at the stage of preliminary investigation. The first position is to develop the equal powers of the defender with the investigator (lawyer investigation); the second is to establish the institute of the investigating judge; the third is to develop the institute of petitions and complaints. A critical assessment of each position is given. The main directions of the possible development of law-making in solving the issue of fixing adversarial principles in pre-trial proceedings are determined. The author’s opinion is justified that the most promising solution to the problem is the further improvement of the criminal procedure institute of petitions and complaints as an element of adversarial nature, which allows the defense party to increase the level of legal opportunities to defend legitimate interests in pre-trial proceedings. The materials of the article are of some value for the further scientific search for a solution to the problem under consideration and the creation of favorable conditions for its practical (problem) solution.