The stand-off between the fugitive soldier identified by his surname Lim and the authorities came to an end on Monday afternoon after 42 hours with an attempted suicide.
Authorities say the 22-year-old shot himself in the side with a K-2 rifle, and has been transported from a military hospital to a private hospital for treatment.
"The military collected the K-2 rifle and ammunition from the fugitive soldier… who is expected to be referred to the military investigative authority so they can determine a motive and cause for the attack."
Lim was on the list of soldiers that needed special attention as he had struggled adapting to military life.
He was deemed unfit for frontline service in a personality test last year, although he retook the test months later and passed.
Lim killed five of his comrades and injured at least seven others in a grenade and gun attack on Saturday.
He later fled to an area some 10 kilometers from the military base where he opened fire on troops before being cornered by the military.
The attack is the latest in a series carried out by Korean soldiers.
Eight were killed back in 2005 after a solider went rogue at his military base, and a similar incident on Ganghwa island in 2011 left four dead.
Kim Ji-yeon, Arirang News.