The shooting at the Covenant Christian school on Monday left three children and three adults dead.
The victims have been identified as nine-year-olds Evelyn Dieckhaus, Hallie Scruggs and William Kinney and Cynthia Peak, a substitute teacher, aged 61; Katherine Koonce the school’s headteacher, aged 60; and Mike Hill, a custodian, aged 61.
The Metropolitan Nashville Police Department released six minutes of footage from officers’ body-worn cameras which showed officers storming into the school minutes after the shooting was reported at 10.13am.
MNPD Officers Rex Engelbert, a 4-year veteran, and Michael Collazo, a 9-year veteran, were part of a team of first responders to the Covenant campus Mon morning. They fired on the active shooter, who was killed. This is their body camera footage. https://t.co/17qsZM6bNp pic.twitter.com/g4b0nMTFRD
— Metro Nashville PD (@MNPDNashville) March 28, 2023
It showed police clearing one classroom after another on the first floor before venturing up the stairs to the second floor.
Shots can then be heard seconds before the suspect, identified by police as Audrey Elizabeth Hale, comes into view.
It shows police responding to the suspect, with one repeatedly shouting: “Get your hands away from the gun!”
The attacker was shot by police and pronounced dead at 10.27am.
The shooter had legally bought seven firearms in recent years and hid the guns from their parents before the attack, police also said on Thursday.
Investigators said they were examining a “manifesto” written by the shooter, a 28-year-old ex-pupil of the school, hoping to learn the motivation behind the US’s latest mass shooting.
Authorities said Hale was not on their radar before the attack. Police say Hale was under a doctor's care for an undisclosed emotional disorder.
Police earlier said Hale had drawn a detailed map of the school, including potential entry points, and conducted surveillance of the building before carrying out the massacre.
In an interview with NBC News, police chief John Drake said he believed the suspect had “some resentment for having to go to that school” as a child.
He told reporters: “We have a manifesto, we have some writings that we're going over that pertain to this date, the actual incident.
“We have a map drawn out of how this was all going to take place."
The suspect was with two assault-style weapons and a pistol, at least two of which were believed to have been obtained legally in the Nashville area.
Police have given unclear information on Hale’s gender. For hours on Monday, police identified the attacker as a woman.
At a late afternoon press conference, the police chief said Hale was transgender. After the news conference, police spokesperson Don Aaron declined to elaborate on how Hale identified.
In an email on Tuesday, police spokesperson Kristin Mumford said Hale “was assigned female at birth. Hale did use male pronouns on a social media profile”.
The shooting is the 90th school shooting - defined as any incident in which a gun is discharged on school property - according to researchers at the K-12 School Shooting Database.
Last year saw 303 school shootings, the highest of any year in the database, which goes back to 1970.
On Tuesday, the White House spokeswoman Karine Jean-Pierre said that President Joe Biden has already taken multiple gun-related actions by executive order but called upon lawmakers to pass a ban on assault weapons.
“We need Republicans in Congress to show some courage," she told MSNBC in an interview. “Enough, enough, enough."
Hours after the shooting, Biden urged lawmakers to pass tougher gun reform legislation.
The Covenant School, founded in 2001, is a ministry of Covenant Presbyterian Church in the Green Hills neighbourhood of Tennessee’s state capital. It has about 200 students.