The public prosecutor's authority to direct judicial police officers is prescribed in the article 196, clause 1 of the Criminal Procedure. According to the article 53 of Public Prosecutor's Office Law, the judicial police officer is obliged to obey the order of the “prosecutor concerned.”Generally, studies on the meaning of those two articles, which defines the basic relationship between police and prosecutor, reached a conclusion that there are two key factors in the articles; “the public prosecutor has the authority to direct judicial police officers in criminal investigation” and “the officers has to comply with prosecutor's orders”Based on the vertical relations, the prosecutor directly commands judicial officers in investigating criminal cases, including ones which may be, or shall be, done by the Office. However, not only scholars but even Police Agency has not raised any objection to the custom.
To establish proper relationship between Police and Prosecutors, two studies should proceed the revision of the relevant articles; on the legal relation of the agencies by constructing Criminal Procedure and Public Prosecutor's Office Law in a different point of view, and on the current relation in the field.
Changing focus in interpretation of Criminal Procedure and Public Prosecutor's Office Law, from the aspect of authority(the text of “the prosecutor's authority to criminal investigation and direction of judicial officers" in Criminal Procedure and Public Prosecutor's Office Law) to that of obligation(the text of “must investigate criminal cases" in Criminal Procedure), it is possible to construct laws about the relationship different from traditional one. It also is possible to limit the power of prosecutors by redefining "prosecutor with authority to direct judicial officers" and “prosecutor concerned.”The construction of law may differ from standpoints, and in reality, prosecutors have general and unlimited authority over judicial police officers, as is against "check and balance". At least, general authority over police officers should not be allowed. Thus, in the revision of Criminal Procedure led by Presidential Committee on Judicial Reform, it is necessary to limit the power of prosecutors with new provisions, clarifying that only the prosecutor in charge of a certain case has the authority to direct judicial officers engaging the case.