This article examines the foundations underlying the establishment of the investigating judge (examining magistrate) alongside the public prosecutor and the rationale for separating the prosecutorial function from the investigative function in criminal proceedings. The main research question is what legal and practical grounds justify the establishment of the investigating judge alongside the public prosecutor and to what extent the criticisms directed at this institution (investigating judge) are justifiable. The study adopts a descriptive-analytical approach and is based on library research and documentary sources.

The principle plays an important role in impartiality, equality of arms and separation of powers. Moreover; it increases the precision of the investigating by division of tasks and specialization in the antithetical duties (investigating and prosecuting) and through supervision over the investigation phase. Moreover, the division of functions and powers prevents the accumulation of power in the hands of a single authority and exposes the measures of authorities to supervision of another. In other words, it minimizes mistakes and abuses. In contrast, criticism of the interrogation status, which is a violation of neutrality, has led to reforms in the judicial system of some countries, including France.