The 28-year-old former student who killed three children and three adults at a Christian grade school in Nashville on Monday was under a doctor's care for an "emotional disorder" and had purchased seven guns ahead of the shooting, the city's police chief said on Tuesday.
New details about Audrey Elizabeth Hale emerged hours after police released harrowing video showing officers storming the Covenant School and conducting a room-to-room search before confronting and fatally shooting the assailant.
Hale employed two assault weapons and a handgun during the assault on the elementary school, the latest in a long string of US mass shootings that have turned guns into a hot-button political issue.
Those three guns were among seven Hale bought legally from five area stores, Metropolitan Nashville Police Chief John Drake told reporters on Tuesday.
Hale's parents did not know that Hale was in possession of seven guns, the chief said, adding that they were under the impression that the suspect had owned only one gun but had sold it.
Drake said it appeared that the suspect had some sort of training with firearms. Hale fired on officers from the second floor as they arrived in patrol cars while standing back from large windows to avoid becoming an easy target.
Hale left behind a detailed map of the school showing entry points as well as what Drake described as a "manifesto" indicating that Hale may have planned to carry out shootings at other locations.
Drake previously said Hale self-identified as transgender. He referred to Hale using female pronouns on Tuesday, though Hale used male pronouns on a LinkedIn page that listed recent jobs in graphic design and grocery delivery.
The chief said investigators still have not established a motive.
The newly released six minutes of footage, edited together from the body-worn cameras of two responding officers, starts with an officer retrieving a rifle from his trunk as a staff member tells him that the school is locked down but that two children are unaccounted for.
"Let's go! I need three!" the officer yells as he enters the building, where alarms can be heard ringing.
The video shows officers passing by bulletin boards and cubbies as they clear one room after another before heading upstairs, where one says, "We've got one down."
Amid the sound of gunfire, the officers race down the hallway – past what appears to be a victim lying on the ground – and into a lounge area, where the suspect is seen dropping to the floor after being shot.
Officer Rex Engelbert and Officer Michael Collazo – whose body cameras provided the footage – both fire several rounds at the suspect. The video shows the assailant still moving on the ground as another officer repeatedly yells, "Get your hands away from the gun!"
Monday's violence marked the 90th school shooting – defined as any incident in which a gun is discharged on school property – in the United States this year, according to the K-12 School Shooting Database, a website founded by researcher David Riedman.
Last year saw 303 such incidents, the highest of any year in the database, which goes back to 1970.
The three 9-year-old children who were killed were identified as Evelyn Dieckhaus, Hallie Scruggs and William Kinney. Also shot dead were Katherine Koonce, 60, the head of school; Mike Hill, 61, a school custodian; and Cynthia Peak, 61, a substitute teacher.
Scruggs' father, Chad, is a pastor at the Covenant Presbyterian Church, which is connected to the school. In a statement given to ABC News, he said the family was heartbroken.
"Through tears we trust that she is in the arms of Jesus who will raise her to life once again," the statement read.
The school in a statement said, "Our community is heartbroken. We are grieving tremendous loss and are in shock coming out of the terror that shattered our school and church."
Nashville police began receiving calls about a shooter at 10:13 a.m., spokesperson Don Aaron told reporters on Monday. The suspect was pronounced dead by 10:27 a.m.
"The police department response was swift," Aaron said.
The body camera footage showed officers rapidly searching for the shooter, in contrast to videos showing officers in Uvalde, Texas, waiting inside Robb Elementary School for more than an hour in May as a gunman inside a classroom continued an attack that claimed the lives of 19 children and two adults.
A number of officers responding to a school shooting in Parkland, Florida, in 2018 remained outside the building rather than immediately pursuing the suspect, according to a state commission's investigation. Seventeen students and staff members died in that attack.
Both incidents prompted fresh scrutiny of police protocols for active shooters, which call for officers to engage the suspect at once to prevent loss of life.
Police previously released surveillance footage showing the shooter arriving at the school and gaining entry by shooting through a glass door. The suspect is seen stalking through empty hallways as emergency lights flash, brandishing a rifle and entering rooms, seemingly looking for people.
The Covenant School, founded in 2001, serves about 200 students from preschool to sixth grade in the Green Hills neighbourhood of Tennessee's state capital, according to the school's website. (Reuters)