Grandfather of Texas school shooter: 'I'm sorry'

The grandfather of the 18-year-old who killed 21 people at an elementary school in Uvalde, Texas apologized for his grandson's actions.

"I’m sorry. I’m very sorry. I am," Rolando Reyes told reporters in Spanish. "I feel a lot of pain for all of them because a lot of the kids are my friends’ grandchildren. And I’m sorry. I'm sorry to all the families."

The shooter shot his grandmother before going into Robb Elementary and killing 19 students and two faculty members.

Reyes said a neighbor called him to let him know there was a shooting. "It still hasn't sunk in," he said.

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Reyes said he didn't know his grandson had purchased weapons days before the shooting. He said if he had known, he would have reported him.

"I don't like weapons. I cannot be around weapons," he said. Reyes described his grandson as quiet. "He didn't talk very much," Reyes said.

Reyes told ABC News that his grandson stopped attending school this year and would go to work with him sometimes.

He added that the teenager lived with him because he had problems with his mother.