How key issues in Yoon's impeachment trial differ from previous cases

President Yoon Suk Yeol delivers his final statement during the 11th hearing at the Constitutional Court in central Seoul, Tuesday. Courtesy of Constitutional Court

After the conclusion of the hearing sessions for President Yoon Suk Yeol's impeachment trial at the Constitutional Court, public attention is now on the timing of the final ruling and its anticipated outcome.

To make a well-informed prediction about the outcome, it’s useful to look at Korea’s two previous presidential impeachment cases — those of Roh Moo-hyun in 2004 and Park Geun-hye in 2016-17 — to gauge how Yoon's trial might unfold. Legal experts The Korea Times interviewed shared similar views on the analysis of these past cases, yet they diverged on the potential implications and likely outcome of the impending ruling.

Legal scholars explained that three key elements must be met for an impeachment to be upheld: relevance to official duties, evidence of illegal conduct and the severity of the violation.

Roh, Korea's president from 2003 to 2008, was impeached for breaching political neutrality during elections. However, the Constitutional Court ruled that the violation was not serious enough for his removal, leading to the dismissal of the impeachment.

Former President Roh Moo-hyun displays a somber expression upon hearing the news of his impeachment motion passing at the National Assembly, as he visits a factory in Changwon, South Gyeongsang Province, March 12, 2004. Korea Times file

At the time, 193 out of 271 lawmakers in the National Assembly voted in favor of Roh's impeachment, passing the motion. The Constitutional Court issued its ruling 63 days after the case was submitted, following seven hearings, with the final decision announced 11 days after the hearings ended.

Park, who was South Korea's president from 2013 to 2017, faced multiple accusations of violating the Constitution and the law. Key allegations included allowing her close aide, Choi Soon-sil, to interfere in state affairs, access confidential information and facilitate bribery. These actions were considered both illegal and severe enough to warrant impeachment.

In Park’s case, 234 out of 300 lawmakers voted in favor of impeachment and the motion was submitted promptly to the Constitutional Court. The trial included 17 hearings and concluded with a final ruling 91 days later, resulting in a unanimous 8-0 decision to remove Park from office. At the time of the impeachment motion, public support for her removal was over 80 percent.

Former President Park Geun-hye arrives at the Seoul Central District Court in Seoul, May 25, 2017. Korea Times photo by Hong In-ki.

In Yoon's case, the central issue of the impeachment trial is the constitutionality of his emergency martial law declaration on Dec. 3. Unlike Park's case, which involved multiple constitutional violations, Yoon's case focuses mainly on this single issue. However, the controversy surrounding the facts complicates matters — some view the martial law declaration as a mere warning, as Yoon claims, while others see it as a significant threat to the constitutional order. These differing perspectives contribute to divided public opinion and lead to varying legal interpretations among scholars.

"A key difference in Yoon’s impeachment trial is the ongoing allegations of bias within the Constitutional Court. When insurrection charges were removed from the National Assembly's impeachment documents, Assembly prosecutors attributed the decision to the court’s recommendation, raising concerns of unfairness. Additionally, controversies over some justices' social media activity and procedural decisions fueled further debate. Despite Article 40 of the Constitutional Court Act requiring the application of criminal procedure law in impeachment cases, the court has chosen not to follow it, making this a significant point of contention," Chang Young-soo, a professor at Korea University School of Law, told The Korea Times in an interview.

Chang warned that regardless of whether the impeachment is upheld or dismissed, it could deepen divisions rather than resolve conflicts. Given these concerns, he stressed the need for a thorough cross-examination of the case's evidence and facts, criticizing the court for appearing to rush the proceedings.

Attorney Kwon Oh-hyun, a partner at Dowoo Attorneys & Counselors, also agreed that removing the insurrection charges from the National Assembly’s original impeachment documents raises procedural concerns.

"The insurrection charge was withdrawn from the grounds for impeachment, but such a change should have required renewed approval from the National Assembly. Failing to do so raises procedural concerns," Kwon said.

He also warned that the Constitutional Court proceedings could resemble a trial by public opinion and be influenced by popular sentiment.

"The impeachment motion was submitted on Dec. 14, with 204 out of 300 lawmakers voting in favor. The hearings concluded after 73 days, following 11 sessions. Comparing this to past cases, a ruling is expected around March 14. The key factor is public opinion — while about 75 percent of the public supported impeachment at the time, recent polls show about 40 percent now oppose it, resembling Roh’s case, where public opposition was over 60-70 percent, rather than Park’s, where over a vast majority of people supported the impeachment. As a result, justices may be divided along ideological lines," Kwon noted.

President Yoon Suk Yeol prepares to deliver his final statement during the 11th hearing of his impeachment trial at the Constitutional Court in Seoul, Feb. 25. Courtesy of Constitutional Court

Defense against factual or procedural flaws

In contrast to the concerns raised about the facts, evidence and procedural flaws in Yoon's impeachment trial, other legal scholars hold a different view.

Kim Seon-taek, a professor at Korea University School of Law, countered such claims by referencing the exact wording of Article 40 of the court law.

"Article 40 of the Constitutional Court Act states that criminal procedure law applies 'as long as it does not contradict the nature of constitutional trials.' The phrase 'as long as it does not contradict the nature of constitutional trials' means that the application is not automatic but conditional. The term 'applies' in Korean legal documents signifies that it can be modified. In other words, applying it means adapting it to fit the nature of impeachment trials," Kim told The Korea Times.

He emphasized that impeachment is essentially a disciplinary procedure aimed at a specific type of public official and that it is fundamentally different from a criminal case. He said many legal scholars seem to overlook this distinction.

"Impeachment trials are not criminal cases, and the outcome is not a criminal sentence; it only removes a public official from office, and it does not legally affect criminal proceedings," Kim said, adding that in an impeachment trial, the standard of proof is not as high as in a criminal case.

"In criminal procedure law, the admissibility of evidence must meet the standard of 'beyond reasonable doubt,' meaning the facts in question must be clear enough to leave no room for any reasonable doubt. Therefore, judgments should rely only on firsthand testimony in court, and documents prepared elsewhere or hearsay should not be considered. This is a fundamental principle of criminal procedure law. However, impeachment trials are a form of disciplinary process, and when admitting evidence, it only requires a high degree of probability," the professor pointed out.

Indeed, the Constitutional Court has stated that even if criminal procedure law is applied to impeachment trials, it is "limited to the extent that it does not contradict the nature of constitutional trials." They emphasized that there is no issue with this approach, citing the example of Park's impeachment case, in which witness statements were accepted as evidence.

Regarding the intense debate over the testimonies of some witnesses, Kim noted that since the judges can evaluate the testimonies in a holistic manner, the actual truth will ultimately be revealed. He added, "Even if there are some conflicting testimonies, I don't believe they will have a significant impact on the verdict."

Police officials guard the front gate of the Constitutional Court in Seoul, Wednesday. Yonhap

Han Sang-hoon, a professor at Yonsei University Law School, said, "While the testimony by Hong Jang-won, first deputy director of the National Intelligence Service, seems to contain some inaccuracies, the authenticity of the list itself cannot be disregarded."

Hong had testified in court that the NIS had compiled a list of individuals involved in anti-government activities and he faced questions about the accuracy and intent behind it.

Han further emphasized that what matters is not the number of people on the list but the fact that there was an attempt to arrest those named.

"The existence of the list itself is consistent, and it remains unchanged in the larger context," he said.

When asked about removing the treason charge from the assembly documents, Kim explained that the country's criminal procedure law — which is to be applied to the impeachment case as long as it does not contradict the nature of constitutional trials — stipulates that the bill of indictment can be changed, when the identity of the facts charged is not disturbed.

"Under our legal system, once a lawsuit is filed, modifications can be made to the bill of indictment, as long as the foundational facts maintain their identity. In this case, the factual basis for impeachment remains unchanged . Thus, in terms of legal assessment, the decision not to contest the charge of treason is permissible — keeping the facts and grounds for the lawsuit intact while applying a different legal interpretation," Kim said.

Cheon Kwang-seok, professor emeritus of Yonsei University Law School, agrees with Kim's view on the matter.

"The Constitutional Court has the authority to determine, at its own discretion, how to legally consider the impeachment charges in relation to one another. As long as the identity of the basis of the impeachment is maintained, the mere addition, withdrawal, or modification of the applicable legal provisions does not constitute an addition, withdrawal, or modification of the impeachment charges themselves," the professor explained.

Lee Heon-hwan, a profess Ajou University Law School and former head of the Constitutional Research Institute, expects that it won’t take much time for deliberations at the court, given that there aren’t many issues in this case.

"Considering the time required to write the reasoning for each cause, I believe the ruling will be issued by mid-March at the latest. Resolving national turmoil quickly is also the Constitutional Court’s duty," Lee said.