The investigation into the “Dec. 3 Martial Law” case has been mired in controversy from the outset, as disputes persist over which agency—the prosecution, police, or the Corruption Investigation Office for High-ranking Officials (CIO)—has the authority to investigate insurrection charges. Reforms under the Moon Jae-in administration stripped prosecutors of the power to directly investigate such cases. Simultaneously, the CIO, established during this period, was excluded from initiating investigations into insurrection. Legal experts have argued that, under legal principles, the police should conduct initial investigations before forwarding cases to prosecutors for further review and indictment.
Despite this framework, all three agencies launched separate investigations. Prosecutors claimed their involvement was necessary, arguing that the police, alleged co-conspirators in the insurrection, could not impartially investigate President Yoon Suk-yeol and other suspects. Meanwhile, the CIO asserted its jurisdiction by categorizing insurrection as a related crime of abuse of power, which falls under its purview. These overlapping claims exposed a “gray zone” in the legal framework, a byproduct of rushed reforms.
The judiciary, expected to resolve these ambiguities, instead granted warrants requested by both the prosecution and the CIO. Following this, the CIO took over cases involving President Yoon from the police and prosecution and conducted its investigation independently without judicial objections. Critics argue that, under public pressure to expedite the probe, the judiciary only deepened the confusion rather than providing clarity.
A lawyer in Seoul’s Seocho district said, “If judges had applied strict standards to resolve disputes over investigative authority, it could have eased backlash from President Yoon’s legal team and prevented further legal confusion. Instead, the judiciary has amplified the controversy.”
On Jan. 23, Yoon’s defense attorney, Yoon Kap-keun, criticized the CIO’s decision to transfer the case back to prosecutors. He stated, “The arrest and detention of President Yoon were based on illegal warrants issued by a court without jurisdiction and executed by an agency lacking investigative authority.”
This dispute dates back to December when Chun Dae-yeop, head of the National Court Administration, acknowledged in a parliamentary session that the police held investigative authority in insurrection cases. However, on Dec. 10, Nam Cheon-gyu, a presiding judge at the Seoul Central District Court, granted a warrant requested by prosecutors for former Defense Minister Kim Yong-hyun. The judge determined that prosecutors could investigate insurrection due to its ties to related crimes involving public officials, such as the national police chief.
Shortly after this decision, the CIO invoked its authority under the Act on the Establishment and Operation of the Corruption Investigation Office for High-ranking Officials to take over the case from the police and prosecution. The CIO claimed that while it could not directly investigate insurrection, it could do so indirectly by linking the crime to abuse of power, a charge within its jurisdiction. This rationale drew criticism from legal experts, with one calling it “a flawed approach, using a lesser offense with a maximum penalty of five years in prison to justify probing treason, a crime punishable by death.”
Despite opportunities to resolve these jurisdictional conflicts, the judiciary upheld the CIO’s claims. Judges at the Seoul Western District Court approved the CIO’s requests for two arrest and search warrants for President Yoon on Dec. 31 and Jan. 7, as well as a bench warrant on Jan. 19. These decisions effectively validated the CIO’s authority to proceed with its investigation, further fueling the debate over jurisdictional overreach.