By ACACIA CORONADO and JIM VERTUNO Associated Press

UVALDE, Texas (AP) — The governor of Texas says the gunman who killed 19 children and two teachers at an elementary school had warned on social media minutes before the attack that he was going to shoot up a school.

Gov. Greg Abbott says the shooter, 18-year-old Salvador Ramos, used an AR-15 in the attack Tuesday at Robb Elementary School in Uvalde.

About 30 minutes before the shooting, Ramos made three social media posts.

According to the governor, Ramos posted that he was going to shoot his grandmother, then that he had shot the woman, and finally that he was going to shoot an elementary school.

Abbott says Ramos had no known criminal or mental health history. "Evil swept across Uvalde yesterday," Abbott said.