By Lee Kyung-min

The Supreme Court upheld a lower court's ruling, Thursday, that sentenced a man to 18 months in prison suspended for three years for beating an intruder until he was brain dead.

The man, surnamed Choi, 22, beat the thief, surnamed Kim, 55, who broke into Choi's home and rummaged through his drawers at around 3 a.m. on March 8, 2014.

Choi punched and kicked Kim until he fell to the floor, and further attacked him by using a leather belt and an aluminum pole taken from a laundry drying rack.

Kim remained in a coma for nine months in the hospital and died in December 2014.

Choi, who had been charged with assault with a weapon, was later charged with manslaughter.

The lower court sentenced him to 18 months in prison, and the high court suspended the term for three years, considering that Kim caused the deadly confrontation by breaking into Choi's home.

While Choi argued that he attacked the thief out of self defense, the top court upheld the rulings of two lower courts that dismissed his claim, saying Choi acted excessively.

"Choi went beyond self defense and his attack became an assault, as he kept on beating Kim in the head for a long time even though Kim was trying to flee without posing any additional physical threat to Choi's safety," the court said.

"Choi continued to beat Kim instead of seeking other less violent means to overpower him such as tying him up. His act constitutes an assault," the court added.