On October 25, the special prosecution team led by Jo Eun-seok filed an appeal against the life imprisonment sentence handed down by the Seoul Central District Court to former President Yoon Suk-yeol for insurrection charges. Yoon's legal team submitted their appeal the previous day, and the appeal trial is set to take place in the newly established Seoul High Court's dedicated insurrection department starting from October 23. The special prosecutor's office asserts that the trial court erred in its findings of fact, legal interpretation, and sentencing, arguing that the severity of the charges warrants a reconsideration of Yoon's role in the alleged insurrection.

The special prosecution also contests the court's timeline for Yoon's preparation for martial law, asserting that discussions of martial law started around October 2023, following military appointments, and intensified with Yoon allegedly mentioning 'emergency powers' during meetings with top military officials in March 2024. A key piece of evidence cited by the special prosecutor's office is notebook entries from former Intelligence Chief Noh Sang-won, who has been implicated as a behind-the-scenes figure in the insurrection case. However, the initial court dismissed these claims, asserting that Yoon's decision to declare martial law was made only two days prior to its official announcement on December 1, 2024, thus negating the prosecutor's argument regarding Yoon's premeditated intentions.

Additionally, the special prosecutor's office is intent on correcting what they view as an overly stringent standard set by the trial court for establishing accomplice liability in insurrection cases. The initial court ruled that mere participation in a rebellion was insufficient; there needed to be an evident understanding among co-conspirators of the goals of undermining the constitution. This interpretation resulted in an acquittal for former National Investigation Division Chief Yoon Seung-young, while former Minister of Interior and Safety Lee Sang-min received a seven-year sentence for his involvement. The ongoing appeal is closely monitored, with significant implications for accountability and justice in South Korea's political landscape.