SANTA FE, Texas — The Texas student charged in the school shooting at Santa Fe High School posted an image on Facebook of himself wearing a “Born to Kill” shirt and used his father’s shotgun and pistol in the attack that left 10 dead and 10 wounded, authorities said Friday. A motive wasn’t immediately clear for the nation’s deadliest attack since February.The suspect, 17-year-old Dimitrios Pagourtzis, was held without bond in the Galveston County jail on charges of capital murder, said the county sheriff, Henry Trochesset. Gov. Greg Abbott said both weapons were owned legally by the suspect’s father.It was not clear whether the father knew his son had taken them. Authorities urged parents nationwide to lock away their guns to keep them away from children.Abbot said at a news conference that “unlike Parkland, unlike Sutherland Springs, there were not those types of warning signs.” He was referring to the Feb. 14 school shooting in Florida and one in November inside a church in a town near San Antonio. Abbott said the early investigation showed no prior criminal history for Pagourtzis — no arrests and no confrontations with law enforcement.“The red-flag warnings were either nonexistent or very imperceptible,” Abbott said, though he acknowledged Pagourtzis had recently posted a picture of a T-shirt reading “Born to Kill” on his Facebook page.