Judges sharing powers in the judicial control and solution of the case on the merits is a reasonable way to resolve the problem of the court competence concerning the requests for detention. The author finds it reasonable when some members of the judiciary are exempt from criminal cases in the first instance to be responsible for the judicial control. However, this requires the solution of the organizational issue related to the stuff size of courts, primarily courts with a single judge and two judges. The legality and validity of the judicial decision concerning the investigator's request for detention is of fundamental importance for the implementation of the operative judicial control by the court. The unjustified restriction of citizens' constitutional rights, including the right for freedom and personal security, can lead to dramatic and even tragic consequences. The judicial control in the preliminary investigation stage serves to create additional procedural guarantees for the participants of the criminal proceedings, as it has advantages over the prosecutorial supervision over the legality of investigation and institutional control. Its effectiveness largely determines the rule of law in the criminal prosecution. The effectiveness of the judicial control depends on how the legislator and judicial practice determine the court competences considering the investigator's request for detention and remand in custody. During the judicial reform focused on further protection of the rights of participants in the proceedings, the legislator came to the conclusion that it is the court independent from the investigative authorities shall check whether there are legitimate grounds for the decision to detain or to prolong the period of detention. Initially, the courts decided to evaluate submissions only in terms of legality of the grounds for detention, without verifying their validity. After some time, it became clear that without checking the validity of the investigator's request it would be difficult for the court to take a legal and well-grounded decision. The analysis of the provisions of Art. 108 of the Russian Federation Code of Criminal Procedure shows that the legislator relates the decision to choose detention as a pre-trial restriction to both the procedural status of a particular person and to the availability of reliable data, confirming the validity of suspicion or accusation of a criminal act. The judge must be convinced that the guilt of the person delivered to the court has been proved at least in one episode, that the preliminary investigation bodies have the required evidence in the criminal case, and that this evidence will not become inoperative.