The Defense Ministry has concluded that an South Korean Army officer found shot dead at a base in Iraq last month had committed suicide due to stress from his duties. First Lt. Oh Jong-soo, 27, was found dead on May 19 with his chin wounded by a gunshot at a barber shop inside the camp of the Zaytun unit in the northern Iraqi city of Irbil. Oh is the first death of South Korean troops since they were deployed there in 2004. "We have found no evidence showing he was attacked and killed," Col. Oh Young-o told reporters Monday after military investigators ended their probe. Oh’s rifle and an empty cartridge were found near Oh's body, he said, adding the Army concluded that he killed himself due to pressure from his work. Oh's body was flown to Seoul and an autopsy was performed to determine the cause of death. But Oh's family called for thorough investigation into the cause of death, refusing to hold a funeral. "The K-2 rifle found at the scene belonged to 1st Lt. Oh and a bullet was fired from the rifle," the chief investigator of the incident said, adding that his fingerprints were also found on the rifle and the broken seal of the cartridge. He is believed to have pulled the trigger with the rifle pointed at his chin, he said. The chief investigator said the victim might have been under stress from serving as both company leader and officer in charge of medical administrative affairs. "He was at odds with some medical officers at his company," he added.