South Korea’s Corruption Investigation Office for High-ranking Officials (CIO) transferred the case of impeached president Yoon Suk Yeol to the Seoul Central District Prosecutors’ Office for prosecution on Thursday, which marks the fourth day of the Constitutional Court impeachment hearing.

In a press conference held on Thursday, the CIO deputy director Lee Jae-Seung said that impeached president Yoon has never cooperated with the CIO’s investigation since it began and decided that the investigation would be more efficient by transferring the case to the prosecutors.

Lee also said that the CIO had transferred over 30,000 pages of evidentiary records to prosecutors relating to his conspiracy with former defense minister Kim Yong-hyun, to incite a riot by declaring martial law to disrupt the constitutional order.

Instituting prosecutions for any corruption of the President is not within the CIO’s statutory power. Under South Korea’s Act on the Establishment and Operation of the Corruption Investigation Office for High-Ranking Officials, the CIO’s power to institute prosecutions for any corruption of a high-ranking official is limited to law enforcement officials, including the Chief Justice and a Justice of the Supreme Court, the Prosecutor General, a judge or a prosecutor or a police official not lower than a superintendent general.

When asked whether Yoon and his legal team would cooperate with the prosecutors’ investigation, Yoon’s lawyer Yoon Gap-geun said that many factors may affect their decisions to cooperate, including the prosecution’s investigation attitude.

While Yoon’s criminal liability is pending investigation and prosecution, his impeachment is now under review by the Constitutional Court within 180 days according to Article 65 of South Korea’s Constitution. Concluding from the third and fourth day of the hearing, Yoon’s lawyer suggested that the half-day declaration of martial law was necessary because it did not intend to dissolve the National Assembly but to draw public attention to the urgent constitutional crisis. The crisis includes the abuse of power by the Democratic Party as the legislative majority to paralyze the executive government and cut the government budget recklessly. In addition, Yoon claimed that the National Election Commission’s refusal to cooperate with external investigations of election fraud allegations also contributed to the crisis. Yoon further contended that the country has also been facing foreign interference, which is detrimental to national security.

Following Yoon’s declaration of martial law, the National Assembly passed a motion to impeach Yoon. Whether Yoon will be impeached and be criminally liable for the declaration of martial law continues to be a developing story.