Criminal procedural proof, which is the core of pre-trial proceedings, on the one hand, predetermines the justice of the final court decision in a criminal case, on the other hand, is able to protect a person from illegal and unreasonable criminal prosecution in a timely manner. The achievement of this is in direct correlation with the procedural capabilities of the defender to effectively participate in such establishment of evidence. However, the study of the opinions of academia, practitioners and generalization of the results of investigative practice, judicial statistics has led to the belief that in the course of establishment of evidence in a criminal case there exists an unreasonable discretion of the investigator and the interrogating officer over the guarantees of the individual’s right to protection enshrined in criminal procedure law. The defense counsel, despite the strengthening of these guarantees by the Federal Law of April 17, 2017 No. 73‑FZ, is not yet able to overcome the accusatory bias of the investigator, interrogator and properly defend the suspect, the accused. The author makes a proposal to solve this problem, taking into account the features of the modern form (type) of pre-trial proceedings.