President Yoon Suk Yeol attends a hearing for his impeachment trial at the Constitutional Court in central Seoul, Tuesday. Joint Press Corps

President Yoon Suk Yeol defended himself in his impeachment trial at the Constitutional Court, Tuesday, reiterating his claim that his imposition of martial law was an act of governance and thus did not violate the Constitution.

This marks the first time in Korean history that a sitting or former president of the country has ever publicly attended an impeachment trial.

It was also Yoon's first official appearance before the public since his declaration of martial law on Dec. 3, 2024. After he was detained on Jan. 15 to be questioned over allegations of insurrection and abuse of power, some reporters caught a glimpse of him inside a vehicle after he was questioned at the headquarters of the Corruption Investigation Office for High-ranking Officials (CIO).

Yoon, who has since been confined at Seoul Detention Center in Uiwang, Gyeonggi Province, came to the court in central Seoul in a prisoner transport vehicle belonging to the justice ministry.

He wore a suit with a necktie instead of a prison uniform and was not handcuffed.

He began his statement by delivering an apology to the justices of the court.

"I feel deeply apologetic to the justices for the burden caused by my impeachment case," the president said.

"Throughout my public service career, I have held a strong belief in liberal democracy. As the Constitutional Court exists for the protection of the Constitution, I ask the justices to carefully deliberate on the matter in every aspect."

President Yoon Suk Yeol attends an impeachment hearing at the Constitutional Court in central Seoul, Tuesday. Joint Press Corps

During the trial, Yoon's legal defense team argued that the president had no intent to execute or implement any of the orders in the martial law decree.

The decree is one of the key issues in the impeachment case. It included a ban on all political activities, such as the operations of the National Assembly, local councils and political parties. The National Assembly, playing the role of the prosecution in the impeachment case, argued that this violated the Constitution, undermining the essence of representative democracy.

"The decree was made only to meet formality, and there was no specific intent to implement it and no concrete plan for its execution, and no organizational structure established to carry it out," Yoon's legal representatives said.

The defense team further claimed that the purpose of the decree was "to restrict illegal actions by the National Assembly, if any, not to dissolve the legislative body or prohibit normal legislative activities."

It also stated that former Minister of National Defense Kim Yong-hyun drafted the initial version of the decree, which Yoon later revised.

"Kim prepared the draft based on previous examples from when military regimes granted the president the authority to dissolve the National Assembly. Yoon modified it, particularly removing the public's curfew provision," the defense said.

Yoon's defense team also denied allegations that he ordered the arrest of key political figures, including then ruling party leader Han Dong-hoon and Assembly Speaker Woo Won-shik. They also dismissed as baseless the claim that Yoon gave an order to assassinate Han.

The impeachment trial on President Yoon Suk Yeol is held at the main courtroom of the Constitutional Court in central Seoul, Tuesday. Joint Press Corps

During the trial, acting Chief Justice Moon Hyung-bae questioned the president directly.

The chief justice asked Yoon about election fraud allegations, which the president's defense team cited as a key reason for the martial law declaration. In response, Yoon expressed his doubts about the fairness of the voting process.

"When the National Intelligence Service conducted a limited inspection of the National Election Commission's (NEC) electronic equipment in October 2023, it found numerous problems," Yoon said. "My intention was not to uncover election fraud, but to conduct a comprehensive review of the NEC's electronic systems."

He claimed that his actions were not intended to promote conspiracy theories but to verify the facts.

When asked about allegations that martial law forces were deployed to block the National Assembly from passing a resolution to lift martial law, Yoon argued that such a decision could not be blocked or delayed by those means.

"The National Assembly passed a resolution swiftly, even though it did not fully comply with parliamentary procedures. Nevertheless, upon seeing this, I immediately ordered the withdrawal of the military forces," he said.

Police buses line the streets near the Constitutional Court in central Seoul, Tuesday, to maintain order amid protests by supporters of President Yoon Suk Yeol. Korea Times photo by Shim Hyun-chul

The acting chief justice announced during the hearing that the court had accepted a request from the president's legal team to call former Minister of the Interior and Safety Lee Sang-min and Senior Presidential Secretary for Economic Affairs Park Chun-seop as witnesses. Park is slated to testify on Feb. 6, and Lee on Feb. 11.

Previously, Yoon's team had requested the addition of at least 24 witnesses, including many Cabinet members, to support their claim that the martial law declaration was prompted by the opposition's "disruption of state governance."

The court also plans to proceed with the questioning of the former defense minister on Thursday, as scheduled.

Later on Tuesday, the Corruption Investigation Office for High-ranking Officials (CIO) sent six investigators to formally summon Yoon and conduct an on-site interview at Seoul Detention Center.

However, it was later revealed that Yoon had visited a hospital in central Seoul for a medical check-up after the hearing at the Constitutional Court. Yoon and his escort vehicles left the court at 4:42 p.m. and went to the Armed Forces Seoul Capital District Hospital for the examination. According to sources, Yoon returned to the detention center after the check-up.