A shooter opened fire at a private Christian grade school in Nashville on Monday, killing three children and three adults, officials said. The suspected shooter was fatally shot by police at Covenant School in the city’s Green Hills neighborhood, authorities said.

Authorities have identified the victims as 9-year-olds Evelyn Dieckhaus, Hallie Scruggs, and William Kinney, 61-year-old Cynthia Peak, 60-year-old Katherine Koonce, and 61-year-old Mike Hill. All three adults worked at the school. Police identified the shooter as Audrey Hale, a 28-year-old from Nashville, who officials said was armed with at least two assault weapons and a handgun.

Nashville Police Chief John Drake said their preliminary investigation into the shooting indicated that it was a targeted attack. The probe suggested that the shooter was at one time a student at the school, although Drake did not know exactly when they may have attended.

Police discovered “a manifesto” as well as “maps drawn of the school in detail,” according to the chief.

“We’ve also determined there were maps drawn of the school in detail of surveillance, entry points, etc. We know and believe that entry was gained by shooting through one of the doors, is how they actually got into the school,” Drake said. He described the guns used to carry out the shooting as two “AR-style weapons” — a rifle and a pistol — in addition to another handgun. Authorities believe that two of the weapons may have been obtained legally and locally, according to the police chief.

Drake confirmed earlier on Monday that the three children were identified and their families had been contacted.

“Right now I will refrain from saying the ages, other than to say, I was literally moved to tears to see this and the kids as they were being ushered out of the building,” Drake said at the time. Officials established a reunification center nearby where students inside the school were transported in the aftermath of the shooting.

“When we send our kids to school, or to any place of safety, we expect them to live, learn, have fun and come back from that day’s experience. We don’t anticipate things like this,” he told reporters later on Monday afternoon.

Officers entered the first storey of the school building and began to clear it when they heard gunfire on the second level, said Don Aaron, a spokesperson for Metropolitan Nashville Police Department. The officers moved upstairs and saw the shooter firing, and at that point they “engaged” the shooter, who was fatally shot by two of the five responding police officers at the scene, he said.

The shooter entered Covenant School through a side door and traversed the building, moving from the first floor to the second floor and “firing multiple shots,” Aaron said.

Covenant is a private Christian school in Nashville for preschool through 6th grade, CBS affiliate WTVF reported. Last year, the school held an active shooter training program, the station reported.

Special agents at the Tennessee Bureau of Investigation were also involved in the response.

Tennessee Governor Bill Lee said he was “closely monitoring the tragic situation at Covenant” in the wake of the shooting, alongside state law enforcement and highway patrol officers.

“I am closely monitoring the tragic situation at Covenant, & the @TNDeptofSafety & @TNHighwayPatrol are assisting local law enforcement & first responders at the scene,” the governor wrote on Twitter. “As we continue to respond, please join us in praying for the school, congregation & Nashville community.”

President Joe Biden addressed the shooting in televised remarks on Monday afternoon.

“It’s sick,” he said. “It’s heartbreaking. A family’s worst nightmare.”

Biden said the administration is “monitoring the situation really closely” before again calling on Congress to pass his assault weapons ban, as he did after the mass shooting in Monterey Park, California, in January.

“We have to do more to stop gun violence,” he continued. “It’s ripping our communities apart and ripping at the very soul of the nation.”

First Lady Jill Biden also acknowledged the school shooting in remarks given during the National League of Cities conference, and said that she is “truly without words.”

“Our children deserve better,” Biden continued. “We stand, all of us, we stand with Nashville in prayer.”