The six victims of the mass shooting at a private Christian school in Tennessee included three 9-year-old children, the school's headmaster, a substitute teacher and a school custodian, officials said.
The shooter was armed with two assault rifles and a handgun when they shot through locked doors of The Covenant School in Nashville on Monday, entered the school and killed six victims inside, police said.
The attacker, a former student of the school, was confronted by police officers and fatally shot around 14 minutes after the attack began, police said.
Officials identified the three children as Evelyn Dieckhaus, William Kenney and Hallie Scruggs, all students at the small Christian private school.
The school is part of The Covenant Church, a Presbyterian church where Hallie's father serves as lead pastor.
The Tennesseean reported Evelyn was a third grader at The Covenant School. Her older sister, a fifth grader there, spoke at a vigil Monday evening at Woodmont Christian Church, according to the Tennessean.
"I don’t want to be an only child," Evelyn's sister said through tears, according to the Tennessean.
Covenant's head of school, Dr. Katherine Koonce, 60, was among the adult victims.
On the school’s website, Koonce wrote the school is "about more than simply educating our students." She added the school’s mission was "helping children become who God intends them to be."
Michael Hill, a 61-year-old custodian, and Cynthia Peak, a 61-year-old substitute teacher, also died in the shooting.
Metropolitan Nashville Police Chief John Drake said the shooter, Audrey Hale, 28, had carefully planned the attack with a document, detailed maps and surveillance.
"There’s some belief that there was some resentment for having to go to that school," Drake told NBC News' Lester Holt.
Drake said the shooter might have targeted The Covenant School, but didn't appear to have singled out any victims.
“She targeted random students in the school ... whoever she came in contact with, she fired rounds," Drake said of the shooter, who he later said was transgender.
Two of the three firearms used in the shooting were legally obtained in the Nashville area, Drake said.
Investigators searched the attacker's vehicle and residence after the attack, and found a document and other writings.
"We have some writings that we’re going over that pertain to this date, the actual incident," Drake said Monday. "We have a map drawn out of how this was all going to take place."
Drake added there appeared to be other locations the shooter intended to target, according to the document and writings investigators found.
"It indicates that there was going to be shootings at multiple locations, and the school was one of them," Drake said.
A team of five officers confronted the attacker on the second floor of the school, and two of them fired shots, authorities said.
Drake commended the officers for their quick actions, saying in a press conference it could have been "far, far worse."
The officers prevented more deaths at the school, Nashville Mayor John Cooper said during a press conference.
"Let us praise our first responders, 14 minutes, 14 minutes, I believe under fire, running to gunfire," Cooper said.