The North Korean soldier who defected to the South Monday via the truce village of Panmunjeom drove a jeep to get near to the area.
According to South Korea's Joint Chiefs of Staff on Tuesday, the soldier got out of the vehicle and continued fleeing south across the military demarcation line.
"The defector approached the enemy guard post using a car until the tires got stuck in the drainage pipes. He exited the car and fled across the Military Demarcation Line. We maintained surveillance and traced his movements via the security system."
The official added that the soldier took cover near a building on the southern side of the JSA.
However in the process he was shot several times by other North Koreans.
" Four North Koreans chased after the defector, firing around 40 rounds."
The defector is thought to be in his twenties or thirties, and wore a uniform of low rank.
He is currently at Ajou University Hospital in Suwon, south of the capital, where he underwent five hours of surgery.
The doctor in charge there said the patient suffered from five to six gunshot wounds, which damaged several of his organs.
He's in critical condition, and it's unclear whether he will live.
The patient is currently in intensive care, however, but the doctor added that he'll need more surgery.
Kim Hyun-bin, Arirang News.