Arrest, suicide attempt, and indictment On 8 December, Kim was arrested on charges relating to the martial law declaration. A police raid was conducted at the Presidential Office, with investigators presenting a search warrant that specified Yoon as the suspect. On 10 December, at 23:52
KST, Kim attempted to commit
suicide, using his clothing to try and
hang himself in the bathroom of the detention facility he was being held in while in custody. Shin Yong-hae, the head of the Ministry of Justice's Correctional Service, stated at a National Assembly plenary session; "A control room worker discovered Kim Yong-hyun attempting suicide by using string connecting his underwear and underwear pants in the bathroom of the waiting area before a warrant against him was to be issued." Shin also stated; "He gave up and came out when we immediately went in and opened the door. He is currently being housed in a protection facility and I have received reports that he is in good health." On 27 December, Kim was indicted on insurrection charges. The indictment revealed that President Yoon met with Kim, Commander Yeo, and others about 10 times since March 2024 to discuss the imposition of martial law. Yoon ordered a nighttime curfew reference to be dropped from the decree. Kim denied allegations that Yoon had ordered the military to storm the National Assembly to prevent lawmakers from convening and passing a resolution nullifying martial law. However, he admitted to recommending declaring martial law to Yoon and to writing a note to Finance Minister Choi Sang-mok, instructing the establishment of an emergency legislative body during martial law. Alongside Yoon, Kim was also accused of ordering lawmakers to be dragged out of the parliament, to which Kim responded with; "The situation was very chaotic, I thought someone might get crushed to death. So I said to pull them out for now to reduce the risk of serious harm. That’s what I meant." On 5 February, the National Assembly planned an on-site questioning session at the Seoul Dongbu Detention Center, aimed to directly question key figures involved in the martial law declaration, but it was cancelled after Kim refused to cooperate. Despite his witness chair already being set up, Kim declined to appear at the session, insisting that he could not attend it due to "trial preparation." Kim had previously refused to attend any parliamentary hearings held by the special committee. Democratic party member Ahn Gyu-back apologized to the committee for Kim's behavior, and added that the committee would file a complaint against Kim for contempt of the Assembly at next week's plenary session. Democratic Party representative
Han Byung-do would voice his annoyance, stating; "Refusing to cooperate with the investigation is an outright rejection of the truth. If he is so confident and honorable, why can't he stand in front of the public?" On 21 February, Kim applied for a suspension of execution in protest of the prosecution's sending of his prosecution's investigation records to the Constitutional Court, but it was rejected. On 3 March, Kim would call Yoon's arrest "illegal and unconstitutional" in a letter he wrote in his prison cell. In the letter, Kim would also call for Constitutional Court justices
Moon Hyung-bae,
Lee Mison and
Chung Kyesun to be "punished." Kim also criticized students at
Ewha Womans University that were in favor of Yoon's impeachment, calling them "a group of evil." Democratic Party Speaker Hwang Jung-a would criticize the letter, stating "[Kim] is nothing different from Yoon, who regards anyone who criticizes him as an anti-government force and someone to be eliminated." During a court hearing on 17 March, Kim claimed his reasoning for urging Yoon to declare martial law was because he wanted to "root out anti-state forces and overcome political deadlock". Kim would also deny that the martial law declaration was an attempted self-coup. On 4 April, the Constitutional Court unanimously upheld Yoon's impeachment and removal from office over the martial law declaration. On 27 May, former Prime Minister and Acting President Han Duck-soo and former Finance Minister
Choi Sang-mok were barred from traveling abroad after being named as a suspect in the insurrection case against Yoon Suk Yeol over his martial law declaration, after CC-TV footage of Han conversing with Kim Yong-hyun the day of the martial law declaration was discovered. On 28 May, former Commander of the Defense Intelligence Command Roh Sang-won was indicted on bribery charges, which revealed that he, along with Kim Yong-hyun, were accepting bribes and valuables back in August 2024 from active-duty soldiers under the pretext of requesting promotions.
Proceedings Kim Yong-hyun's trial began on 27 March, with a total of six witness examinations. Kim's trial is being shared along with former commander Roh Sang-won and former military police commander of the 3rd Field Army Command Kim Yong-gun, both who had ties with Kim during the martial law order. Over the following two months, five more hearings were held with the three, however these hearings were kept private as they were charged in connection with key insurrection-related duties. The fifth hearing was scheduled for 23 May. On 28 May, Judge Ji Gwi-yeon, who was assigned the trial case, announced that Kim's trial would now be publicized; "to ensure transparency and uphold the rule of law in handling serious charges such as insurrection." On 4 June, Kim submitted a withdrawal request to the court, however he withdrew it later that day. On 9 June, the South Korean District Court announced they were considering additionally charging Kim, along with former Army Intelligence Command Chief Roh Sang-won, with
tampering with evidence after it was discovered that on 5 December 2024, Roh gave Kim a secret
burner cellphone device, who initialized it before returning it to Roh. It was also discovered that Kim continued to use a different burner cellphone until his arrest. Prosecutors believe Roh and Kim may have used these devices to contact prosecution officials. They were also considering indicting Kim on suspicion of bribery, illegal provision of a secret cellphone, and suspicion of military blacklist; as well as
threats of violence for ordering court justices to be "punished" in a prison letter he wrote in March. The court also confirmed that Kim was indeed second-in-command of the martial law order. On 16 June, Kim rejected the bail offer and filed an appeal to the court. He argued that conditional release against his will right before the expiration of the detention period was "effectively another form of detention that restricts personal freedom." On 19 June, Special Prosecutor Cho Eun-seok received investigation records regarding suspicion of
obstruction of justice and tampering with evidence. As a result, Cho additionally indicted Kim on the two charges, a decision Kim claimed was "illegal." The court decided to give Kim a separate trial for these charges, and that its first hearing would be held on 17 July. On 17 July, the first hearing for Kim's additional trial began, however it only lasted twenty minutes because Kim refused to respond when asked if he would like to have a citizen participation trial. On 11 August, former
Minister of the Interior and Safety Lee Sang-min testified as a witness, without Kim present. On the same day, Kim filed a request to cancel his detention with the court handling the additional indictments, as well as a transfer of jurisdiction, requesting that the case be tried in a different court. In September, the court publicly announced that the insurrection trial should conclude by the end of the year. On 18 September, Kim filed a recusal application in an attempt to drop all of the charges filed against him, which was rejected. On 17 October, Kim filed a lawsuit against the court, claiming that "the act of sending the investigation records to the Constitutional Court is an unconstitutional and illegal act without legal basis," and requested a stay of execution. This was also rejected due to lack of sufficient legal standing. On 11 November, Kim was fined 5 million won and, along with Yoon Suk Yeol and Lee Sang-min, was issued an arrest warrant for failing to appear at Han Duck-soo's trial as a witness. On 19 February 2026, Kim was convicted and sentenced to 30 years in prison. ==References==