The Constitutional Court said that it will deliver a decision on the impeachment trial of Prime Minister Han Duck-soo on March 24. When the Constitutional Court began hearing of President Yoon Suk-yeol’s impeachment trial, it promised to expedite the process of trial due to the urgency and gravity of the case, but the ruling of the case of Prime Minister Han, who was impeached later than Yoon, will come first. It will be interesting to see if the Constitutional Court will include a judgement on the illegality of Yoon’s martial law declaration in its decision.

The Constitutional Court said on March 20, “The sentencing for the impeachment trial of Prime Minister Han Duck-soo will be held at the court at 10 a.m. on March 24.” It added that it does not plan to announce the sentencing date for Yoon's impeachment trial until this week.

As a result, the decision will come 87 days after Han was impeached by the National Assembly on December 27 last year. It is the first judicial decision of a high-ranking official to be impeached or criminally prosecuted since the imposition of martial law.

Han was impeached for five reasons, including “aiding and abetting Yoon’s martial law declaration and rebellion,” “refusing to appoint a constitutional court judge,” “vetoing bills mandating special counsel investigations into First Lady Kim Keon-hee and Marine Corps Corporal Chae’s death” “attempting jointly conduct state affairs with former People Power Party leader Han Dong-hoon,” and “avoiding the appointment of prosecutors for a permanent special investigation team for Yoon’s rebellion.” The Constitutional Court concluded the proceedings for Han’s case after holding a pretrial hearing and a hearing. The National Assembly requested an additional defense to review the investigation records, but was not accepted.

Han’s impeachment case is considered as a bellwether that enables people to grasp the court’s decision of Yoon’s impeachment trial because the decision of Han’s case could reveal the constitutional court justices' judgment on martial law. The National Assembly argued that Yoon's declaration of martial law was unconstitutional and illegal, and that the actions of Prime Minister Han, who participated in the process, were also against the Constitution and the law. There is a possibility that the Constitutional Court will make some judgments on the “adoption of evidence from interrogations of suspects by investigative agencies” and the “limits of changing the grounds for prosecution, such as withdrawing the rebellion charge,” which Yoon is taking issue with.

If the Constitutional Court recognized the unconstitutionality and illegality of martial law in Han’s case, it is likely to uphold the same judgment in Yoon’s case. “Unlike the recent impeachment trials of Choe Jae-hae, chair of the Board of Audit and Inspection of Korea, and Lee Chang-soo, chief of the Seoul Central District Prosecutors Office, which the Constitutional Court recently sentenced, Han was prosecuted under a direct link to the imposition of martial law,” said Han Sang-hee, a professor at Konkuk University School of Law. ”We may be able to get some insight into the judgment on the case of President Yoon as there is commonality.”

Others argue that it would be difficult to directly link Han's case to Yoon's impeachment. This is because the engagement in martial law declaration is a small part of the impeachment charges against Han, and judgments will be made on other reasons as well. If the Constitutional Court finds that Han was not involved in the process of martial law declaration at all, the court may decide that it is not a reason for impeachment regardless of the judgment on the legality of martial law declaration.

“The constitutionality or illegality of martial law is unlikely to be a major factor in the decision to impeach Han, as the reasons for impeachment are different from those of President Yoon,” said Noh Hee-beom, a former lawyer at the Constitutional Research Institute. Jang Young-soo, a professor at Korea University Graduate School of Law, also said, "It is controversial that Yoon led the imposition of martial law and caused an act of rebellion, but it is hard to see Han as an accomplice because he claimed that he did not know in advance.”

In fact, in his closing argument, which lasted about an hour and a half on February 19, Han refuted the reasons for impeachment by the National Assembly one by one and asked for the case to be dismissed. Han said, “I didn't know in advance what the president was planning (about martial law declaration),” adding that he tried his best to convince the president to reconsider. As for the failure to appoint the three nominees for constitutional court judges recommended by the National Assembly, he said, “The acting president is a temporary position,” adding that a parliamentary agreement was inevitable to secure the legitimacy of the appointment.

The Constitutional Court has been criticized for taking the “safe route” by putting its decision on Han’s case ahead of Yoon’s case. As the judges' deliberations over Yoon's impeachment trial are expected to be lengthy, they may be trying to reduce confusion by deciding the other case first, which is relatively simple in logic. Professor Han said, “As the country is in a serious state of chaos, the Constitutional Court may have had the idea of cleaning up the mess before delivering a decision on Yoon’s impeachment trial.”

With the sentencing date for Han’s impeachment trial set for the 24th, it is expected that the decision on Yoon’s impeachment trial will be made on the 25th or later that week at the earliest. If the Constitutional Court sets the sentencing date for Yoon's impeachment trial on the 26th, it will overlap with the sentencing date for Democratic Party of Korea leader Lee Jae-myung's appeal against the Public Official Election Act.