1968 – South Korea’s spy agency uncovers the underground Unification Revolutionary Party, a pro‑North Korean organization that later faces a massive crackdown [2].

1974 – Authorities accuse civilian army worker Kang Eul‑seong of trying to rebuild the Unification Revolutionary Party on North Korean orders, leading to his arrest [2].

1976 – The Seoul Eastern District Court executes Kang Eul‑seong for alleged National Security Act violations, despite later doubts about the evidence [2].

2019 – The Moon Jae‑in administration repatriates two North Korean fishermen who confessed to killing 16 crew members, a case later cited in the 2020 border‑killing controversy [5].

Sept 22, 2020 – Fisheries official Lee Dae‑jun disappears during a Yellow Sea inspection, is shot by North Korean soldiers and his body is burned, prompting the Moon government to label the incident a “defection” [1][5].

Oct 2022 – Former Board of Audit chief Choi Jae‑hae leaks second‑level military intelligence about the 2020 Lee Dae‑jun case in a press statement, violating secrecy rules [1].

Dec 2023 – Choi Jae‑hae repeats the classified disclosure in another press release, further breaching military‑secret protocols [1].

Dec 4, 2025 – The Supreme Court upholds the acquittal of inter‑Korean sports official Kim Kyung‑sung, ruling that his 2010 letter and 2011 wreath to North Korea do not constitute a National Security Act violation [6].

Oct 10, 2025 – Yangpyeong County official dies after being questioned by the Min Joong‑ki special prosecutor team; a 21‑page suicide note alleges coercion, prompting a Human Rights Commission complaint [14].

Dec 2025 – A Seoul court clears former top security officials (including Suh Hoon and Park Jie‑won) of involvement in a cover‑up of Lee Dae‑jun’s killing, citing lack of evidence [9].

Dec 26, 2025 – The Seoul Central District Court acquits five ex‑security leaders—Suh Hoon, Park Jie‑won, Suh Wook, Kim Hong‑hee and Noh Eun‑chae—of concealment charges related to the 2020 border murder, ending a multi‑year prosecution [9].

Dec 29, 2025 – The National Intelligence Service announces it will drop the 2022 complaints against Suh Hoon and Park Jie‑won, apologizing for “undue suffering” after its internal review finds factual and legal flaws [8].

Jan 1, 2026 – Prosecutors consider appealing the December acquittals; President Lee Jae Myung warns that “accountability should be considered,” while Prime Minister Kim Min‑seok calls the indictment “fabricated” [7].

Jan 2, 2026 – Prosecutors state they will appeal the acquittals of Suh Hoon and Kim Hong‑hee, but drop appeals against Park Jie‑won, keeping the legal battle over the 2020 killing alive [5].

Jan 19, 2026 – The Seoul Eastern District Court posthumously acquits Kang Eul‑seong of National Security Act charges; his daughter says, “the family has fought for 53 years and does not expect an instant apology,” highlighting lingering demands for accountability [2].

Feb 3, 2026 – Seoul Metropolitan Police raid the Board of Audit and Inspection, seizing documents after former chief Choi Jae‑hae’s alleged leaks; the audit report had concluded that the Moon administration “neglected, concealed and distorted” facts about Lee Dae‑jun’s death [1].