A South Korean army officer found dead in Iraq last month is believed to have killed himself due to pressures from work, the Defense Ministry said Monday. The 27-year-old officer, 1st Lt. Oh Jong-soo, was found dead May 19 with a gunshot wound under his jaw in a barber shop at his unit in the northern Iraqi city of Irbil. Oh was among about 1,200 South Korean troops deployed in Iraq on a reconstruction mission. The death was believed to be a suicide because Oh's rifle and an ammunition cartridge were found nearby, and there were no signs of an attack. Oh's body was flown home and an autopsy was performed to determine the cause of death. "We found no evidence that indicates he was murdered," the ministry said in a statement. Oh is believed to have shot himself, the ministry said, adding his fingerprints were found on the rifle and the broken seal of the cartridge, and traces of gunpowder were detected on the palm of his right hand.