NASHVILLE, Tenn. (WKRN) — The shooter who opened fire at a Nashville private school has been identified as a 28-year-old Nashville resident, Police Chief John Drake confirmed Monday afternoon.

Drake said the shooter, Audrey Hale, identifies as transgender and was also believed to have been a student at The Covenant School, the small Christian school where officers say Hale killed six people.

Hale allegedly entered the building by shooting through a side door after driving to the school’s campus, Drake noted. In a Twitter thread Monday night, police shared photos of the doors Hale entered through.

The shooter was armed with two “assault-style” weapons — a rifle and a pistol — as well as a handgun and “significant ammunition,” authorities said. At least two of them were believed to have been obtained legally in the Nashville area.

In a Twitter thread Monday night, police said Hale fired at police vehicles arriving on the scene from a second-floor window.

Hale was shot and killed by police minutes after they arrived on scene, Drake said. He added that the shooting was targeted.

When police entered the school’s first story, they heard gunshots coming from the second floor, police spokesperson Don Aaron said. They immediately “went to the gunfire,” he said, where they found the suspect, armed with two assault rifles and a handgun, who was firing.

The responding officers on the second floor were part of a five-member team, according to Aaron. Two of those officers opened fire on the shooter.

“By 10:27 the shooter was deceased,” he said in a press conference Monday morning.

While police initially said the shooter appeared to be a teenager, police later confirmed their age as 28 years old.

During a Monday evening press conference, Drake said authorities are still working to determine a motive but that detailed maps with information on surveillance and entrances were found after the shooting.

A manifesto with Monday’s date noted on it, as well as additional writings believed to be related to the shooting, are also being reviewed.

Drake said in an interview with NBC News that investigators believe the shooter had “some resentment for having to go to that school.”

Authorities say they have spoken with Hale’s father.

A typical day at The Covenant School would see 209 students and approximately 42 staff members in attendance, according to police.

Three of those staff members and three students were killed Monday. No other major injuries were reported.

One officer reportedly sustained an injury from cut glass, but Aaron said he was not aware of any other injuries to officers.

The Associated Press contributed to this report.