TEHRAN, Young Journalists Club (YJC) - But little else hinted at why Pagourtzis launched his rampage as the school day began in rural Santa Fe, Texas, halfway between Houston and the Gulf of Mexico.
Police said there were no significant red flags that would have drawn attention to him, though the attack was clearly planned.
He entered the school carrying a shotgun and revolver under a long coat and he opened fire on fellow students.
He killed 10, mostly students, and wounded 10 others before surrendering. He also planted homemade explosive devices during the morning assault, but none apparently detonated.
The photograph on his Facebook page, since taken down, shows Pagourtzis in a black shirt and black baseball cap with a peace symbol on it.
His post-high school plans were set: he indicated that he intended to join the US Marines after graduating in 2019.
The family lived in the plain about 30 miles (50 kilometers) southeast of Houston, a region that suffered some of the worst flooding from Hurricane Harvey last year.
Source: AFP