Armed with two assault rifles and a handgun, Audrey Hale drove into the grounds of the Covenant School in Tennessee on Monday morning before shooting dead three children and six staff.
CCTV shows Hale calmly driving a Honda Fit through the car park of the school the 28-year-old attended as a youngster.
It looked like any other morning but within minutes Nashville – and the entire country – would be facing yet another school massacre.
Footage from inside the building shows the shooter firing at the glass door of a side entrance to the private Christain school before climbing through it to gain entry.
With the floor covered in shattered glass, Hale then walks – rifle in hand – past a sign saying “welcome Covenant women”. Hale is then seen scanning a corridor and room marked “church office” before moving further inside the school.
The 28-year-old then walks through another corridor, past the school’s children’s ministry. The exact details of exactly what happened next are to be confirmed by police.
But detectives say Hale opened fire, killing six people - including three children - before moving to the second floor of the building. At 10.13am Nashville Police were called to reports of an active shooter inside the school and rushed to the scene.
The map below shows how the shooting unfolded in the building:
On arrival, the first five responding officers heard gunfire coming from the second floor of the building, which is located about 14km (8.8 miles) southwest of Nashville city centre.
Officers went upstairs and confronted the shooter, “who had been firing through a window at arriving police cars”.
Two policemen then opened fired and Hale was killed at 10.27am, Nashville Police said.
Students Evelyn Dieckhaus, Hallie Scruggs and William Kinney, all aged nine, died in the incident.
Headmistress Katherine Koonce, 60, was among of the adult victims of the shooting, according to police, as were staff members Cynthia Peak and Mike Hill, both aged 61.
Detectives are working to establish a motive and are studying a “manifesto” and map left behind by Hale, who was a former student at the Covenant Presbyterian School.
Police have identified the suspected shooter by their name at birth; Hale reportedly was a transgender man who used he/him pronouns, though law enforcement officials initially described the suspect as a woman in the aftermath of the shooting. Police did not provide another name but on the suspect’s social media accounts they refer to themselves as Aiden.
After the killing, parents rushed to the school to see if their children were safe and tearfully hugged their kids, and a stunned community held vigils for the victims.
Rachel Dibble, who was at a nearby church where children were taken to be reunited with their parents, described everyone as being in "complete shock".
"People were involuntarily trembling," she said. "The children ... started their morning in their cute little uniforms, they probably had some Froot Loops and now their whole lives changed today."
Authorities said Hale was armed with two "assault-style" weapons as well as a handgun. At least two of them were believed to have been obtained legally in the Nashville area.
Police said a search of Hale’s home turned up a sawn-off shotgun, a second shotgun and other unspecified evidence.
Founded as a ministry of Covenant Presbyterian Church, The Covenant School is located in the affluent Green Hills neighbourhood just south of central Nashville that is home to the famed Bluebird Cafe - a spot typically beloved by musicians and songwriters.
The school has about 200 students from pre-school through sixth grade, as well as roughly 50 staff members.
"Our community is heartbroken," a statement from the school said. "We are grieving tremendous loss and are in shock coming out of the terror that shattered our school and church. We are focused on loving our students, our families, our faculty and staff and beginning the process of healing."
Monday’s tragedy unfolded over roughly 14 minutes. Police received the initial call about an active shooter at 10.13am.
Officers began clearing the first storey of the school when they heard gunshots coming from the second level.
Police later said the killer fired at arriving officers from a second-storey window and had come armed with significant ammunition. Two officers from a five-member team opened fire in response, killing the suspect at 10.27am.
Late on Monday night, police released approximately two minutes of edited surveillance video showing the killer’s car driving up to the school from multiple angles, including one in which children can be seen playing on swings in the background.
Next an interior view shows glass doors to the school being shot out and the shooter ducking through one of the shattered doors.
More footage from inside shows the shooter walking through a school corridor holding a gun with a long barrel and walking into a room labelled "church office", then coming back out.
In the final part of the footage, the shooter can be seen walking down another long corridor with the gun drawn.
Mr Aaron said there were no police officers present or assigned to the school at the time of the shooting because it is a church-run school.
President Joe Biden, speaking at the White House on Monday, called the shooting a "family’s worst nightmare" and implored Congress again to pass a ban on certain semi-automatic weapons.
