Nashville school shooter Audrey Hale, a 28-year-old transgender artist and former student, legally purchased the arsenal used in the attack behind the family's back despite serious emotional issues that required a doctor's attention, according to authorities.
Metro Nashville Police Chief John Drake also told reporters Tuesday that a motive in the attack remains unknown, and that the shooter had targeted the school but not any individual victims specifically.
"We've interviewed the parents of Audrey Hale, and we've determined that Audrey bought seven firearms from five different local gun stores here legally," Drake said during a news briefing. "They were legally purchased. Three of those weapons were used yesterday during the horrific tragedy."
Hale's parents told police they were only aware of one firearm, which they believed Hale had previously sold, he said.
NASHVILLE SCHOOL SHOOTING: AUDREY HALE POLICE BODYCAMS RELEASED
"They were under the impression that when she sold the weapon, she did not own any more," he said. "As it turned out she was hiding several weapons inside the house."
He said the shooter was under a doctor's care for an unspecified emotional disorder but was previously unknown to law enforcement.
"Her parents felt she should not own weapons," he said. But Hale secretly had collected an arsenal.
In addition to the three guns recovered at the scene, police took a sawed-off shotgun and another shotgun from the family home. It was not immediately clear what the remaining two guns were.
Hale killed six people Monday, three 9-year-old students, including the pastor's daughter, and three adults.
Hale rolled up Monday around 10:15 a.m. in a Honda Fit, where police discovered the manifesto.
Police also recovered diagrams of the school layout, with possible entry points highlighted, as well as drawing depicting Hale in the same outfit worn during the attack, Drake said.
NASHVILLE SCHOOL SHOOTING: OFFICERS WHO TOOK OUT COVENANT SHOOTER IDENTIFIED
Within 15 minutes, responding officers took down the shooter, who was killed at the scene following an exchange of gunfire.
Police said Hale opened fire on responding officers from a second-story window, before a team inside the building, including Officers Rex Engelbert and Michael Collazo, put an end to the carnage.
The victims were found spread out around the building and were not located in a common area, Drake told reporters.
The first victim, 61-year-old janitor Michael Hill, was found dead near the entrance where Hale shot through a glass door to get inside, he said. According to a GoFundMe for his family, Hill was a father of eight.
School Head Katherine Koonce, 60, was located in a hallway near the office, he said.
The school is part of the Covenant Presbyterian Church, and victims included the pastor's daughter, Hallie Scruggs, as well as Evelyn Dieckhaus and William Kinney, all 9. Cynthia Peak, 61, a substitute teacher, was also killed.
Police said Hale had attended the Covenant School at some point in the past. Records show the shooter went on to graduate high school eight years ago and graduated from the Nossi College of Art last year.