Pre-trial judicial oversight at the initiation stage of prosecution is a fundamental pillar for ensuring fair trial standards and safeguarding the rights of the accused in criminal proceedings. The structure of criminal procedure in any legal system is typically categorized into two models: limited and unlimited—depending on whether an independent supervisory body exists. In the limited model, sensitive decisions such as pre-trial detention or violations of privacy require prior authorization from an impartial judicial authority. In contrast, the unlimited model allows prosecutorial or investigative authorities (such as prosecutors or investigating judges) to act independently. The procedural framework of the International Criminal Court (ICC), designed through collective input from diverse legal systems, adopts the limited model and assigns a supervisory role to the Pre-Trial Chamber. By contrast, Iran’s criminal justice system, lacking such oversight, operates under an unlimited model. This article offers a comparative analysis of these two systems, emphasizing the necessity of establishing an independent judicial oversight mechanism at the investigative stage, and presents practical proposals for integrating such a structure into Iran’s legal framework.