Cho Eun-seok, the special counsel investigating charges of rebellion and treason related to the December 3 Martial Law case, questioned former President Yoon Suk-yeol on October 15 over allegations connected to the so-called “Pyongyang drone operation.” It was Yoon’s first appearance before investigators since his re-arrest in July. Despite his unexpected attendance, after months of refusing to cooperate, he invoked his right to remain silent throughout the questioning.

Yoon arrived at the Seoul High Prosecutors’ Office building in Seocho-gu at around 8:42 a.m. under escort, riding in a Justice Ministry transport vehicle. He entered the underground investigation room surrounded by police and security officers. Since being taken back into custody on July 10, Yoon had repeatedly declined requests for questioning from all three special counsel teams, citing health issues. On August 1, when Special Counsel Min Joong-ki, who is investigating allegations involving former First Lady Kim Keon-hee, attempted to bring him in for questioning by force, Yoon resisted from inside his cell wearing only his underwear.

This time, the investigation was conducted voluntarily after Yoon agreed to appear. The special counsel team had earlier obtained an arrest warrant on October 1 following two prior refusals to appear, and had notified Seoul Detention Center of plans to execute the warrant on October 2. After being informed of the plan, Yoon expressed his willingness to attend voluntarily. However, Yoon’s legal team criticized the move, arguing that the warrant had been sought unilaterally without coordinating schedules with defense lawyers, calling it “a blatant violation of due process.”

During the interrogation, prosecutors questioned Yoon about allegations that he and senior military officials attempted to provoke a North Korean attack to justify declaring martial law. The special counsel team suspects that between October and November of last year, Yoon authorized a covert drone operation in which unmanned aerial vehicles flew over Pyongyang and other areas to drop propaganda leaflets, under the direction of former Drone Operations Commander Kim Yong-dae.

Investigators believe Kim carried out the operation under orders from Joint Chiefs of Staff Operations Director Lee Seung-oh, while former Defense Minister Kim Yong-hyun bypassed the Joint Chiefs chairman to receive reports directly. The special counsel team views Yoon as the final approver of the plan. Together, the four are suspected of conspiring to violate the military chain of command and compromising national security interests by pushing ahead with the disproportionate drone operation.

The special counsel plans to indict the key figures later this month on charges of aiding the enemy (general treason), following the completion of investigations into the other suspects. However, Yoon may still be summoned again for further questioning. Special Counsel Deputy Park Ji-young said, “We have prepared all necessary questions regarding the treason allegations. Whether a follow-up questioning will take place depends on how much can be covered today.”

According to sources, Yoon exercised his right to remain silent from the start of the questioning. His lawyer, who arrived late due to the sudden scheduling, joined the session around 10:14 a.m. Yoon refused to answer even basic identification questions and requested a break after one hour. He remained silent until the questioning ended at 6:51 p.m. In a written statement, Yoon’s legal team said, “The treason-related issues cited in the arrest warrant have already been fully investigated during two prior appearances. There is nothing further to testify or submit.”

The special counsel team said it will review the results of the day’s questioning to determine whether Yoon should be summoned again.