A heavily armed 28-year-old fatally shot three children and three adult staffers on Monday at a private Christian school the suspect once attended in Tennessee's capital city before police killed the assailant, authorities said.
The motive was not immediately known but the suspect had drawn detailed maps of the school, including entry points for the building, and left behind a "manifesto" and other writings that investigators were examining, Police Chief John Drake told reporters.
The latest in an epidemic of deadly mass gun violence that has come to routinely terrorise even the most cherished of US institutions unfolded on a warm spring morning at The Covenant School, whose students consist mostly of primary school-age children.
Drake identified the suspect as a woman by the name of Audrey Elizabeth Hale, 28, a resident of the Nashville area, and referred to the assailant by female pronouns.
In response to reporters' questions the chief said: "She does identify as transgender." Whether the suspect identified as a man or woman was not made clear.
Addressing an early evening news conference, Drake said police were working on a "theory" about what may have precipitated the shooting and would "put that out as soon as we can."
Police began receiving calls of a shooter at The Covenant School at 10.13am. Officers could hear gunfire coming from the school's second floor, Don Aaron, a spokesperson for Metropolitan Nashville Police Department, told reporters.
The attacker gained entry to the school by firing through one of the doors, Drake said.
She had previously attended the school, he said.
Two officers from a five-member team shot at her in what Aaron described as a lobby area and she was dead by 10.27am.
"The police department response was swift," Aaron said.
Deadly mass shootings have become commonplace in the United States, but a female attacker is highly unusual. Only four of the 191 mass shootings since 1966 cataloged by The Violence Project, a nonprofit research centre, were carried out by a female attacker.
Reacting to the shooting in Washington, US President Joe Biden urged Congress again to pass more gun reform legislation.
"It's sick," he said, addressing the issue during an event at the White House. "We have to do more to protect our schools so they aren't turned into prisons... I call on Congress again to pass my assault weapons ban."
Three students were pronounced dead after arriving at Monroe Carell Jr Children's Hospital at Vanderbilt with gunshot wounds, hospital spokesperson John Howser said in a statement. Three adult staff members were killed by the shooter, police said.
Aside from six deceased victims and the shooter, there were no other gunshot victims, police said.
The victims were later identified as Evelyn Dieckhaus, Hallie Scruggs, and William Kinney, all aged 9, along with staffers Mike Hill, 61, a school custodian, Cynthia Peak, 61, a substitute teacher, and Katherine Koonce, 60, listed on the Covenant website as "head of school."
The Covenant School, founded in 2001, is a ministry of Covenant Presbyterian Church in the Green Hills neighbourhood of Nashville with about 200 students, according to the school's website. The school serves preschool through 6th graders and held an active shooter training programme in 2022, WTVF-TV reported.
US Senator Marsha Blackburn, a Tennessee Republican, said on Twitter that her office stands "ready to assist" those affected by the shooting.
But Rosanne Cash, daughter of Nashville country music legend Johnny Cash and a singer-songwriter in her own right, responded by criticising Blackburn's ties to the National Rifle Association (NRA) gun lobby.
"You vote against every common sense gun control bill that comes across your desk, you've taken over $1 million from the NRA and you rank 14th in all Congress for NRA contributions. Spare us the hand-wringing," Cash tweeted.
At the state level, Tennessee in 2021 did away with its permit requirement for carrying a concealed handgun and now allows anyone aged 21 and older to carry a firearm, either openly or concealed, without a permit, as long as they are legally allowed to purchase the weapon.
Possessing a handgun is outlawed in Tennessee for anybody who has been convicted of a felony offence involving violence or drugs.
Nashville Mayor John Cooper expressed sympathy for the victims and wrote on social media that his city "joined the dreaded, long list of communities to experience a school shooting".
There have been 89 school shootings defined as anytime a gun is discharged on school property in the US so far in 2023, according to the K-12 School Shooting Database, a website founded by researcher David Riedman. Last year saw 303 such incidents, the highest of any year in the database, which goes back to 1970.
- Reuters