What we know about the deadly shooting at a Nashville elementary ...

Nashville authorities on Tuesday released graphic body camera footage showing the fatal confrontation between police and an armed assailant who attacked a grade school Monday morning.

Six people — including three children — were killed in the shooting, and the suspected attacker was killed by police within minutes of the first call of an active shooter.

Audrey Hale, who police identified as the shooter, bought seven firearms — including the three guns used in the attack — legally and was in treatment for an emotional disorder, Nashville Police Chief John Drake said Tuesday.

The shooting occurred at the Covenant School, a private elementary school on the grounds of Covenant Presbyterian Church in Nashville's Green Hills neighborhood.

The massacre drew messages of sympathy from politicians including President Biden and others across the country, and it reignited calls for Congress to do more to prevent school shootings.

According to the national Gun Violence Archive, there have been 130 mass shootings in the U.S. so far this year.

Here's what we know about the Nashville shooting and those who died:

How the shooting unfolded

Authorities say they received the first call of an active shooter at Covenant School at 10:13 a.m. local time.

Hale, a 28-year-old from the Nashville area, was a former student of the school. Authorities initially identified Hale as a woman, but later clarified that Hale used he/him pronouns.

Surveillance footage shows Hale driving to the school in a Honda Fit. Dressed in camouflage-style pants, a white T-shirt, a red cap and a black vest, Hale shoots out the glass of a side door and crawls through the opening to access the building. The shooter was armed with two AR-style guns — a rifle and a handgun — as well as a pistol, investigators said.

Local police arrived at the school within minutes of the first 911 call.

Body camera footage released Tuesday shows Officer Rex Engelbert arriving at the school, grabbing his weapon from the back of his vehicle and encountering a woman who appears to be a staff member.

She tells him, "The kids are all locked down, but we have two kids that we don't know where they are." She also describes layout of the school and says children are upstairs.

Engelbert and at least two other officers begin searching the first floor of the school, as an alarm blares. They check check several rooms, including what appear to be classrooms. Some doors are locked and the rooms are dark.

Muffled gunshots can be heard in the background, and Engelbert and the other officers rush upstairs to the second floor.

The gunshots grow louder, and Engelbert enters an atrium and encounters the shooter standing near a window. Engelbert fires four times and the shooter falls to the ground.

Body camera footage from a second officer, Michael Collazo, shows him entering the school on the first floor with a group of other officers.

Collazo and the other officers reached the second floor, where one says "we've got one down" as loud gunshots are heard.

He steps behind Engelbert as the group enters the atrium.

After Engelbert shoots Hale, officers rush the suspect, and Collazo fires four more times.

Engelbert is a four-year veteran of the force, and Collazo is a nine-year veteran.

The officers shot and killed Hale at 10:27 — 14 minutes after the first emergency call.

Authorities said Hale had also been shooting at responding officers through a second-story window.

The victims

On Monday afternoon, police identified the three students and three staff members who were killed.

Evelyn Dieckhaus, age 9, was a third-grader at Covenant School and her sister was a fifth-grader, according to The Tennessean. At a vigil, Evelyn's sister cried as she said, "I don't want to be an only child." Hallie Scruggs, age 9, was the daughter of Chad Scruggs, the senior pastor at Covenant Presbyterian Church, according to CBS News. William Kinney, age 9 Cynthia Peak, age 61, was a substitute teacher, according to authorities. Katherine Koonce, age 60, was identified on the school's website as head of the Covenant School. Mike Hill, age 61, worked as a janitor at the school, police said.

A police spokesperson said Tuesday that investigators had no evidence that any of the victims were specifically targeted.

The investigation

Police say they don't yet have a motive for the shooting.

Investigators were reviewing writings by Hale, who had attended the Covenant School, and had interviewed the suspect's parents.

Chief Drake said during a Tuesday press briefing that the shooter had legally purchased seven firearms from five local gun dealers. Three of those weapons were used in Monday's attack.

According to Drake, Hale's parents thought Hale shouldn't own any weapons and believed he had sold his only gun.

They also told police that Hale was under a doctor's care for an emotional disorder.

The shooter apparently also had detailed maps drawn of the school that identified entry points.