A cousin of the shooter who killed 19 students and two teachers at an elementary school in Uvalde, Texas, was arrested on Monday after his concerned family allegedly told police he threatened to do the same thing.

The 17-year-old was taken into custody on Monday morning on suspicion of making a terroristic threat to a public place after his mother called police.

According to an arrest warrant obtained by HuffPost, she said her son had made concerning statements to his sister that indicated he was going to commit a mass shooting at an elementary school across the street from where they lived in San Antonio.