Military prosecutors on Friday demanded the death penalty for an Army deserter accused of killing and wounding about a dozen unarmed comrades in a shooting rampage in a guard post close to the border with North Korea.

In June last year, the 23-year-old Army sergeant, surnamed Lim, fired at his comrades at a border outpost on the east coast, killing five and wounding seven others. Bullying was found to be the motive for the rampage.

He then ran away from his 22nd Infantry Unit with his rifle and a stash of ammunition. Two days later, he was captured while being under siege by thousands of troops right after a botched suicide attempt.

Two months later, Lim was indicted on charges of murder and desertion.

During his final court-martial hearing held at the First Army Headquarters in Wonju, some 132 kilometers southeast of Seoul, military prosecutors demanded the capital punishment, arguing that he committed a "cruel and premeditated attack" on unarmed comrades."

"Such a severe punishment is inevitable as he has been trying to justify his wrongdoings while putting the blame on his colleagues who had allegedly ostracized him for his behavior," the prosecution said in its argument.

But Lim's lawyer appealed for leniency, contending that the exact cause of the incident has yet to be determined.

"It's questionable if the death sentence can resolve the problem," the lawyer said in his final argument.

Earlier in the day, the military court adopted as an evidence the result of a psychiatric test conducted on Lim for a month from November. According to military sources, the test showed that the soldier was "generally normal."

South Korea's military law stipulates that a soldier faces the capital punishment for killing a superior officer. One of the fallen soldiers was a staff sergeant in Lim's unit.

The sentencing is due to take place on Feb. 3. (Yonhap)