Criminal prosecution was assessed from the perspective of the principle of full defense during police investigation and along corresponding procedures. From the observation of state agency practices regarding criminal prosecution, it was possible to infer that, despite the fact that the 1988 Constitution of the Federative Republic of Brazil sets forth guarantee principles to guide criminal procedures, the performance of state offices is still ruled by a repressive/punitive characteristic that inspired the creation of 1941 Code of Criminal Proceedings. Decisions issued by the Federal Supreme Court, the Superior Court of Justice and the Court of Justice of the State of Minas Gerais were selected once they demonstrated an interpretation that excels in the relativizing procedural guarantees. Even if reforms are carried out to the criminal procedural diploma aiming at better adjusting it to the Federal Constitution, it is not possible to talk about respect for the due criminal procedure while legal decisions insist in softening constitutional principles and infra-constitutional standards that guarantee the rights of those who are subjected to the proceedings. The sacrifice of the due criminal procedure is evidenced not only by such legal practices, but also by the lack of effective full defense once most of those who are subjected to the procedure cannot engage lawyers and the Government fails to comply with the obligation to provide full and free legal assistance through the Public Defender s Office. The absence of effective full defense tarnishes the exercise of citizenship and the criminal procedure is seen as an instrument to legitimate an exclusion that precedes it. The Brazilian State assumes the posture of criminal efficiency to the detriment of respect for constitutional guarantees. From that stand point, is recognized the need to improve the structure of the Public Defender s Office to defend the rights of the disadvantaged ones, due to the technical and legal capacity of its professionals, they can fight authoritarian practices, defending the status libertatis of investigated and accused ones.