At a private Christian school in Nashville, Tennessee, on Monday, a female shooter killed three children and three adults before being shot dead by police. According to investigators, the attacker looked to be a teenage girl.

At 10:13 in the morning, calls about a shooter at The Covenant School, which serves students in kindergarten through sixth grade, started coming in. According to Don Aaron, a spokesperson for the Metropolitan Nashville Police Department, officers could hear gunfire coming from the second level of the school.

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

The victims were identified as Evelyn Dieckhaus, Hallie Scruggs, and William Kinney, all 9 years old, and adults Cynthia Peak, 61; Katherine Koonce, 60; and Mike Hill, 61.

The Covenant School, a Protestant institution established in 2001, identifies Katherine Koonce as its head of school on its website. She is listed as the school's principal on her LinkedIn profile as of July 2016.

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 center, were carried out by a female attacker.

There have been 89 school shootings – defined as anytime a gun is discharged on school property – in the U.S. 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.