The article examines current problems of implementing the constitutional right to qualified legal assistance in pre-trial criminal proceedings. An analysis of legislative provisions regulating the powers of a defense attorney in collecting evidence has been conducted. It is noted that the existing asymmetry of procedural capabilities between the prosecution and defense contradicts the principle of adversarial criminal proceedings. It has been revealed that the limited access of the defense attorney to materials of crime report verification impedes the effective implementation of the right to defense. It has been determined that the absence of legally established forms for recording the results of attorney investigation reduces the evidentiary value of information obtained by the defense. The conclusion is drawn about the necessity of expanding the powers of defense attorneys at the pre-trial stage and improving procedural mechanisms for their implementation

The article is devoted to the development of a scientifically grounded classification of violations of the right to defense in pre-trial criminal proceedings. The author proposes a multi-criteria system for differentiating procedural violations based on the analysis of subjective composition, stages of proceedings, nature of procedural consequences and mechanisms of committing violations. The study identifies key patterns of infringement of defensive rights at the stages of pre-investigation verification, initiation of criminal proceedings and preliminary investigation. Particular attention is paid to analyzing actions of investigative bodies, prosecutorial supervision and judicial control that create obstacles to the exercise of the constitutional right to qualified legal assistance. The author substantiates the necessity of a differentiated approach to substantial and non-substantial violations, highlighting the category of unconditional procedural defects that entail imperative legal consequences. The proposed typology allows systematizing law enforcement practice and developing effective mechanisms to counteract the restriction of procedural guarantees of the defense party in pre-trial stages of criminal proceedings.