Kyung‑yul King was a South Korean Marine Corps sergeant stationed near Kimpo (modern‑day Gimpo), South Korea. Publicly available records provide limited information about his early life, family background, or upbringing. At the time of the incident, King was 27 years old and serving on active military duty.

As a non‑commissioned officer, King had access to military‑issued firearms and explosives, including an M‑16 assault rifle and hand grenades. There are no publicly documented records indicating prior violent offenses or disciplinary actions before the events of January 1971. However, contemporary reports confirmed that King had been drinking heavily shortly before the attack, which was later cited as a contributing factor in the incident.

On the evening of January 18, 1971, Kyung‑yul King committed one of South Korea’s earliest recorded mass shootings. Following a night of heavy alcohol consumption, King detonated two hand grenades inside his Marine Corps camp near Kimpo, sparking chaos among personnel. He then left the base armed with an M‑16 assault rifle and proceeded into a nearby civilian village. There, King opened fire without warning, killing six individuals, two soldiers and four villagersand injuring four additional villagers. His rampage caused fear and devastation in the community, particularly as the attack involved both military and civilian victims. After fleeing into the nearby mountains, King took his own life later that same day, bringing the incident to a grim close. The case raised widespread concern over access to weapons by active military personnel and became a reference point in South Korean military history for internal violence involving service members.