Investigation and Prosecution Are Now Separated, But the Jurisdictional Gray Zone Remains

Separation of Investigation and Prosecution: The System Launches, but the Gaps Remain

The criminal justice reform dividing investigation and prosecution has taken effect, yet a gap remains in the form of potential jurisdictional conflicts. With the launch of the Public Prosecution Office and the Office for Investigation of High-Ranking Officials-level serious crime (Major Crimes Investigation Agency), the prosecution's long-held monopoly over investigative and prosecutorial powers has been split. However, according to Yonhap News, experts point out that the mere establishment of institutions does not eliminate the possibility of jurisdictional clashes. They note that the criteria for determining which of the two new agencies investigates which cases, and where, remain unclear.

Background of the Reform — Aiming to Curb Concentrated Prosecutorial Power

The starting point of the reform was the prosecution's excessive concentration of power. For decades, critics consistently argued that by holding both investigative and prosecutorial authority, the prosecution was positioned to sway political and economic power. Accordingly, a structure was introduced in which investigative authority was separated, leaving the prosecution responsible for maintaining indictments while a separate agency takes on serious crime investigations. The Public Prosecution Office handles prosecution, while the Major Crimes Investigation Agency handles investigation — roles now formally divided.

On paper, the division of roles between the two agencies is clear. The problem arises when the boundary blurs in real cases. Disagreements between agencies can emerge over issues such as whether a case is a serious crime or an ordinary one, and who conducts supplementary investigations before indictment. In fact, from day one, frictions have surfaced as the new system finds its footing, including a dispute over the status of prosecutors seconded to the special investigation team.

The Jurisdictional Conflict Issue — Who Investigates and Who Prosecutes?

The core issue is jurisdiction. Experts cited by Yonhap raise concerns in two specific directions. The first is case assignment. Rules are not precise enough to determine which agency takes over when a case under the Major Crimes Investigation Agency's jurisdiction changes character during investigation, or conversely, when an ordinary case expands into a serious crime. The second is supplementary investigation at the prosecution stage. There are no established rules on whether the Public Prosecution Office can conduct needed additional investigations on its own to sustain an indictment, or whether it must request cooperation from the Major Crimes Investigation Agency.

These gaps could lead to investigative delays. Prolonged inter-agency consultations could miss the golden window for the initial investigation, increasing the risk of evidence destruction. Conversely, if both agencies launch investigations into the same case simultaneously, duplicate investigations could waste personnel and budgets and raise concerns about violations of suspects' rights.

Political positions are also divided. The ruling party views the separation of investigation and prosecution as the institutional completion of checks on government power. In contrast, People Power Party floor leader Jeong Jeom-sik proposed legislation to restore supplementary investigative powers, arguing that abolishing the prosecution amounts to weakening the criminal investigation system. He claims that without the prosecution's supplementary investigative authority, sustaining indictments could become difficult in itself. Civil society groups welcome the separation of investigative powers but say follow-up legislation is essential to ensure inter-agency conflicts are not passed on as a burden to victims and suspects.

Outlook — Follow-Up Legislation Is Key

The remaining task is follow-up legislation at the National Assembly level. Experts propose alternatives such as establishing a jurisdictional coordination body, legally codifying inter-agency consultation procedures, and clearly granting a higher authority final decision-making power in disputes. In particular, the absence of an independent arbitration channel when the two agencies fail to agree is cited as a structural flaw in the reform's design.

Jurisdictional coordination mechanisms are expected to be addressed in bills during parliamentary audits and discussions in the National Assembly's Legislation and Judiciary Committee. While the ruling and opposition parties may find common ground on preventing gaps in criminal investigations, confrontation is expected over whether to restore the prosecution's supplementary investigative authority. The more real-world clashes emerge between the two newly created agencies, the greater the pressure for follow-up legislation will grow. The success of the reform depends not on its launch, but on how quickly the jurisdictional gaps are filled.