The shooter who killed three students and three staff members at a Christian school in Nashville legally bought seven weapons in recent years and hid the guns from their parents before carrying out the attack by firing indiscriminately at victims and spraying gunfire through doors and windows, police said Tuesday.

The violence Monday at The Covenant School was the latest school shooting to roil the nation and was planned carefully. The shooter had drawn a detailed map of the school, including potential entry points, and conducted surveillance of the building before carrying out the massacre, authorities said.

The suspect, Audrey Hale, 28, was a former student at the school. Hale did not target specific victims — among them three 9–year–olds and the head of the school — but did target “this school, this church building,” police spokesperson Don Aaron said at a news conference Tuesday.

Hale was under a doctor’s care for an undisclosed emotional disorder and was not known to police before the attack, Metropolitan Nashville Police Chief John Drake said at the news conference.

If police had been told that Hale was suicidal or homicidal, “then we would have tried to get those weapons,” Drake said. “But as it stands, we had absolutely no idea who this person was or if (Hale) even existed.”

Tennessee does not currently have a “red flag” law, which lets police step in and take firearms away from people who threaten to kill.

On Tuesday night, Tennessee’s governor said one of the victims, 61–year–old substitute teacher Cynthia Peak, was a close friend of his wife, Maria, and that the two had been scheduled to have dinner after Peak taught that day.

“Maria woke up this morning without one of her best friends,” Gov. Bill Lee said, adding that his wife once taught with Peak and another victim, Katherine Koonce, and the women and “have been family friends for decades.”

Hale legally bought seven firearms from five local gun stores, Drake said. Three of them were used in Monday’s shooting. Police spokesperson Brooke Reese said Hale bought the guns between October 2020 and June 2022.

Hale’s parents believed their child had sold one gun and did not own any others, Drake said, adding that Hale “had been hiding several weapons within the house.”

Hale’s motive is unknown, Drake said. In an interview with NBC News on Monday, Drake said investigators don’t know what drove Hale but believe the shooter had “some resentment for having to go to that school.”

Drake, at Tuesday’s news conference, described “several different writings by Hale” that mention other locations and The Covenant School.

Asked at a Senate hearing whether the Justice Department would open an investigation into whether the shooting was a hate crime targeting Christians, U.S. Attorney General Merrick Garland said federal officials were working with local police to identify a motive.

Police have released videos of the shooting, including edited surveillance footage that shows the shooter’s car driving up to the school, glass doors being shot out and the shooter ducking through one of them.

Additional video, from Officer Rex Engelbert’s bodycam, shows a woman meeting police outside as they arrive and telling them that all the children were locked down, “but we have two kids that we don’t know where they are.”

The woman then directs officers to Fellowship Hall and says people inside had just heard gunshots. Three officers, including Engelbert, search rooms one by one, holding rifles and announcing themselves as police.

The video shows officers climbing stairs to the second floor and entering a lobby area, followed by a barrage of gunfire and an officer yelling twice: “Get your hands away from the gun.” Then the shooter is shown motionless on the floor.

Police identified Engelbert, a four–year member of the force, and Michael Collazo, a nine–year member, as the officers who fatally shot Hale. The White House said President Joe Biden spoke Tuesday with Drake, Engelbert and Callazo to thank them for their bravery.