Four people were killed and nine others hospitalized in a mass shooting at Apalachee High School in Winder, Georgia, on Wednesday.

The suspected gunman is in custody and was identified as a 14-year-old student of the school, which is about an hour outside of Atlanta.

The deceased have been identified as: Mason Schermerhorn, a 14-year-old student, Christian Angulo, a 14-year-old student, Richard Aspinwall, a teacher, Christina Irimie, a teacher.

The adults killed were both math teachers, and Aspinwall was also an assistant football coach, according to the school’s website.

Nine other people — eight students and one teacher — were wounded and hospitalized, all of whom are expected to survive.

The suspected gunman has been identified as Colt Gray. Colt will be charged with murder and tried as an adult.

Colt was questioned by law enforcement last year regarding “several anonymous tips about online threats to commit a school shooting at an unidentified location and time,” according to FBI Atlanta and the Jackson County Sheriff’s Office. At that time, there was no probable cause for arrest.

Law enforcement officials arrive to give a news conference outside of Apalachee High School in Winder, Georgia, on September 4.

Student Lyela Sayarath said the suspected shooter left the classroom at the beginning of their Algebra 1 class around 9:45 a.m. When he returned near the end of the class, he knocked to get back in. Another student went to open the door, but Lyela said that student noticed the gun and didn’t open the door. She said the shooter went to the classroom next door and opened fire.

The sheriff’s department received the first reports of the shooting around 10:20 a.m.

Law enforcement arrived shortly after those calls, in addition to two school resources officers assigned to Apalachee High.

A resource officer confronted the shooter, who immediately surrendered to the deputy and was taken into custody,  Barrow County Sheriff Jud Smith told reporters.

When the shooting happened, all schools in the district were placed in lockdown, and police were sent out of an abundance of caution to all district high schools.

The FBI and the ATF were later on the scene working with local and state officials, Attorney General Merrick Garland said.

There were no reports of secondary incidents or scenes, law enforcement sources told CNN.

The gun used in Wednesday’s shooting was an AR-platform weapon, according to the Georgia Bureau of Investigation director. A law enforcement official told CNN earlier it was an AR-15-style rifle.

Apalachee High School had received a phone threat earlier in the morning warning that there would be shootings at five schools and that Apalachee would be the first, multiple law enforcement officials told CNN.

GBI Director Chris Hosey said there’s no evidence of other schools being targeted, but investigators are pursuing “any leads of any potential associates of the shooter that was involved in this incident.” At this point, there’s no evidence that any additional shooter was involved, and no evidence of a list of schools being targeted, Hosey said.

Schools in the county will be closed for the week while the investigation plays out.