Police reports describe concerns eight years ago that the gunman who killed seven and wounded 25 last month in Odessa might have been planning an attack.
CNN reports police in Amarillo, Texas, went to the home of Seth Ator's mother in February 2011 after she told them he had refused to take his mental-health medication and had threatened to end his own in life in a shootout with police.
Officers found a machete hidden in her son's bed and an underground shelter he had dug in the backyard. In a recording the mother shared with police, her son declared, "911 will bow down before me."
Officers concluded Ator might hurt somebody someday. Amarillo police on Sunday didn't immediately respond to an open records request from The Associated Press.