A 14-year-old boy will be charged with murder after four people were killed and nine injured in a shooting at a Georgia high school.
The Georgia Bureau of Investigation said two pupils and two teachers died in Wednesday's attack at Apalachee High School in Winder, Barrow County.
Colt Gray, a student at the school, was arrested by two officers on campus, an official said. He will be tried as an adult.
It has emerged that the FBI interviewed him last year after receiving anonymous tips about online threats to commit a school shooting, but agents did not arrest him at the time.
Officers first received reports of a shooting at the school of around 1,900 pupils at around 10:20 local time (14:20 GMT).
Local sheriff Jud Smith described the attack as "pure evil".
"Within minutes law enforcement was on scene, as well as two school resource officers assigned to the school who immediately encountered the subject," the sheriff said in a news conference.
"The subject immediately surrendered. He gave up, got on the ground. And the officers took him into custody."
Officials said no motive had been identified and that law enforcement did not know of "any targets at this point".
According to the FBI, investigators had visited the suspect in May 2023 and interviewed him and his father about threats posted online which included pictures of guns.
"The father stated that he had hunting guns in the house, but the subject did not have unsupervised access to them," the FBI said in a statement.
The suspect, who was 13-years-old at the time, denied making the online threats and officials "alerted local schools for continued monitoring of the subject".
"At the time, there was no probable cause for an arrest or to take any additional law enforcement action on the local, state or federal levels."
One of those killed on Wednesday was 14-year-old Mason Schermerhorn, who was autistic, according to local outlet WSB-TV.
Family members had posted Mason's photo on social media after they couldn't find him and later reportedly confirmed he did not survive the shooting.
Teacher and coach David Phenix was injured after being shot in the foot and hip, shattering his hip bone, according to his family's social media posts.
He had surgery but was in a stable condition, someone who identified herself as his daughter said on Facebook.
Law enforcement have not said what type of weapon was used, or how many bullets were fired.
The suspect was interviewed and spoke with investigators once in custody, Sheriff Smith said.
"This is going to take multiple days for us to get answers as to what happened and why this happened," he told reporters.
Dozens of police officers swiftly responded to the shooting at the school, which was placed on lockdown and cleared, with pupils taken to a nearby football stadium before being released to their families.
Lyela Sayarath, who was in the alleged attacker's class, told CNN that the suspect left the room at the beginning of their algebra lesson.
She said he came back and knocked on the door, which had locked automatically, but another student refused to let him in after noticing he had a gun.
Ms Sayarath told CNN the attacker then went to the classroom next door, where he began shooting.
Alexsandra Romero, a second-year pupil, said she was sitting in class when someone came barging in and shouted at students, warning them to get down.
"I can just remember my hands were shaking," she told the Atlanta Journal-Constitution. "I felt bad because everybody was crying, everybody was trying to find their siblings.
"I can still picture everything, like the blood, the shouting."
Marques Coleman, 14, said he saw the attacker holding a "big gun" just before the shooting began.
"I got up, I started running, he started shooting like, like 10 times. He shot at least 10 times," he told CBS News, the BBC's US partner.
"My teacher started barricading the door with desks," he said.
After standing up, the pupil said he saw "one of my classmates on the ground bleeding so bad", another girl shot in the leg and a friend shot in the stomach.
Georgia Governor Brian Kemp said on X, formerly Twitter, that he was "praying for the safety of those in our classrooms" and that he was directing "all available state resources" to assist.
Speaking at a campaign rally in New Hampshire, Democratic White House candidate Vice-President Kamala Harris called the shooting "a senseless tragedy".
"It's just outrageous that every day in our country... that parents have to send their children to school worried about whether their child will come home alive.
"It doesn't have to be this way."
Republican White House candidate Donald Trump posted on his social media platform, Truth Social: "These cherished children were taken from us far too soon by a sick and deranged monster.”
Attorney General Merrick Garland, the top law enforcement official in the US, said federal agents were helping the investigation.
