South Korea's Supreme Court upholds prison sentence for Yoon in first martial law case

SEOUL, South Korea (AP) — South Korea’s Supreme Court on Thursday upheld a seven-year prison sentence for former President Yoon Suk Yeol in the first case to reach the country's highest court from his several criminal trials related to his brief imposition of martial law in 2024.

The court upheld an April ruling by the Seoul High Court that found Yoon guilty of infringing on Cabinet members’ right to deliberate before he declared martial law, falsifying the official proclamation to cover up the lapse before later destroying the document, and deploying presidential security forces to illegally resist law enforcement efforts to arrest him weeks after his impeachment.

Martial law lasted only hours before lawmakers broke through a blockade of heavily armed soldiers and police at Seoul’s National Assembly and voted to repeal it, forcing Yoon’s Cabinet to lift the measure.

Yoon remains in detention and did not attend the ruling, which is final. He is still standing trial in other cases, and he has appealed the life sentence he received for the most serious conviction against him, on the charge of rebellion.

In a statement, Yoon’s legal team expressed “deep regret” over the Supreme Court’s ruling, saying the justices concluded a significant case without sufficient review.

The ruling aligned with the views of the Constitutional Court, which, in removing Yoon from office in April 2025, found that his martial law decree lacked legal grounds and failed to follow required procedures.

While Yoon called 11 Cabinet members to his office shortly before declaring martial law on late-night television on Dec. 3, 2024, several participants, including then- Prime Minister Han Duck-soo, have testified that Yoon unilaterally informed them of his decision rather than inviting deliberation. The Seoul High Court said Yoon also violated the rights of nine other Cabinet members by failing to call them to the meeting or notifying them too late.

Though brief, Yoon’s martial law declaration plunged South Korea into a political crisis, paralyzing politics and high-level diplomacy while rattling financial markets. The turmoil eased only after his liberal rival, Lee Jae Myung, won an early presidential election in June 2025.

In addition to appealing his life sentence for rebellion, Yoon is appealing a 30-year prison term in a case accusing him of ordering drone flights in 2024 to deliberately heighten tensions with North Korea and create justifiable conditions for martial law at home. Yoon’s lawyers said the drone flights were a response to North Korea flying thousands of trash-carrying balloons into the South.