During a hearing at the Seoul Central District Court, Special Prosecutor Cho Eun-suk’s team argued that Yoon’s actions constituted a serious threat to South Korea’s “liberal democratic constitutional order,” describing the move as a “self-coup.” Prosecutors said the former president abused his powers in a bid to maintain control, undermining the rule of law and democratic governance.

Yoon’s declaration of martial law in December 2024 plunged the country into a political crisis, sparking mass protests nationwide. Lawmakers from across the political spectrum joined demonstrators in demanding an emergency parliamentary vote, which ultimately rejected the measure. The Constitutional Court later ruled the martial law decree unconstitutional.

Following the ruling, Yoon was impeached, removed from office, and taken into custody. He now faces criminal charges including insurrection and abuse of power related to the martial law declaration.

Court proceedings concluded after an extensive 11-hour trial, during which prosecutors laid out evidence they say proves Yoon deliberately attempted to override constitutional processes. The defence has rejected the accusations, arguing that the former president acted under extraordinary circumstances, a claim prosecutors strongly dispute.

A verdict is expected in February, in what legal experts describe as one of the most consequential political trials in South Korea’s modern history. The case has reignited debate over executive power, democratic safeguards, and the use of capital punishment in the country.

Han had been serving under then-President Yoon Suk Yeol, who declared martial law before being impeached. Han also briefly took on the role of acting president following Yoon’s removal from office.

During the first hearing—where media coverage was allowed—Han expressed his disapproval of the martial law declaration:

“During my nearly 40 years as a public servant, I’ve always believed that our country must develop through a market economy and international credibility. From that perspective, I’d say this situation was hard to accept,” Han told the court in Seoul.

One of Han’s lawyers stated that Han admitted to making a false statement about not having seen any documents from the presidential office on December 3, the day martial law was declared. However, he denied the other charges.

A team of special prosecutors investigating the incident said Han was the most senior official who could have intervened to stop what they described as an “unconstitutional, illegitimate” order.

Yoon is also facing trial on charges of insurrection and has denied any wrongdoing.

Although Han denied aiding in the declaration, he acknowledged partial responsibility for failing to prevent it. He was later impeached, but the Constitutional Court overturned the decision, allowing him to resume office. He eventually stepped down to enter the snap presidential election in June but ended his campaign due to internal divisions among conservative groups.

Lee Jae Myung, representing the centre-left Democratic Party, won the June 3 election and assumed the presidency following Yoon’s removal.