As police become the investigators, design proper control mechanisms

South Korea is on the cusp of a significant shift in its criminal justice system, aiming to establish a clear separation between police and prosecutorial investigative powers. The core principle of the ongoing legislative reform is that prosecutors will no longer conduct investigations, with the police taking the lead. A crucial aspect of this transition is the meticulous design of control mechanisms to oversee police investigations.

The debate has intensified around the concept of 'victim protection,' with some attempting to link it to the retention of prosecutors' supplementary investigation rights. However, legal experts argue this connection is contrived and concerning. The prevailing reformist current seeks to curb prosecutorial power due to accumulated abuses, leading prosecutors to fiercely defend any remaining investigative authority. This includes utilizing political influence, media engagement, and legal circles to protect their vested interests.

Maintaining prosecutors' supplementary investigation rights, critics argue, would create significant negative consequences. It would effectively allow prosecutors to function as both prosecutors and investigators, preserving their large investigative staff and special activity funds. Even if direct investigations are limited, prosecutors could still influence investigations indirectly. The subjective determination of 'case identity' by prosecutors would grant them selective discretion to intervene in investigations based on political or organizational interests. This could also foster a perception of police inferiority and provide fertile ground for preferential treatment of former prosecutors.

To ensure a robust and rights-respecting system, the reforms must include comprehensive control measures for police investigations. Proposals include an 'institutional reciprocity system,' where police officers' crimes are investigated by a special investigative body, and vice versa, to prevent internal cover-ups. Furthermore, legal enforcement is needed to compel the transfer of cases to other investigative agencies if investigators repeatedly fail to comply with legitimate supplementary investigation requests from prosecutors. The introduction of an 'investigative rights protection officer' is also proposed to address complaints and ensure timely corrections or even changes of investigators. Mandatory video recording of all investigations and a fully equipped criminal justice information system are also key components to enhance transparency and accountability.