The victims were identified as Mason Schermerhorn, 14, Christian Angulo, 14, and teachers Richard Aspinwall, 39, and Christina Irimie, 53. Aspinwall and Irimie were both math teachers, according to the school’s website.

All nine of the hospitalized victims had been shot “in some capacity,” Barrow County Sheriff Jud Smith said. All nine were expected to survive, Smith said.

The suspect surrendered when he was confronted by responding law enforcement officers, Smith said. Smith disclosed that the alleged gunman was speaking with authorities and that those conversations were “helping with our investigation.” He was being held at the Barrow County Detention Center.

The alleged shooter used an AR platform-style gun and there was no evidence any other shooters were involved, according to Hosey.

“We’re still trying to clarify a lot of the timeline from the time that he got here to school today to the time the incident took place,” Hosey said in a late-night news conference.

FBI Atlanta said on social media Wednesday night that county authorities had interviewed the suspect last year about online threats to commit a school shooting.

According to FBI Atlanta, the FBI’s National Threat Operations Center found that the posts came from Georgia, and “the FBI’s Atlanta Field Office referred the information to the Jackson County Sheriff’s Office for action.”

The sheriff’s office interviewed the then-13-year-old boy and his father. The boy said he was not responsible for the threats. The father said he had hunting guns in the house, but that his son did not have “unsupervised access to them,” FBI Atlanta said.

“Jackson County alerted local schools for continued monitoring of the subject, FBI Atlanta said. “At that time, there was no probable cause for arrest or to take any additional law enforcement action on the local, state, or federal levels.”

Two gunshot victims were taken to Northeast Georgia Medical Center Barrow and one gunshot victim was taken to Northeast Georgia Medical Center Gainesville. All three had injuries that were not considered life-threatening. A spokesperson for Grady Health System, which operates Grady Memorial Hospital in Atlanta, previously said staff had received one gunshot wound patient from the high school.

In addition to the wounded, multiple patients came into the hospital system with anxiety symptoms and others experiencing panic attacks, a spokesperson confirmed to CBS News.

“This is a very, very fluid investigation,” said Smith. “This is going to take multiple days for us to get answers as to what happened and why this happened.”

Administrators had earlier placed students and faculty on lockdown as reports emerged online of a possible active shooter at the school in Winder, Georgia, which is about 50 miles northeast of Atlanta. Officers were dispatched to the site at approximately 10:23 a.m. EDT, according to the sheriff. The premises were cleared within an hour, the school said, and students started being released to their families.

According to Smith, law enforcement was notified of the threat thanks to a new security system that had been installed about a week earlier. Smith noted there were three school resources officers on campus at the time of the shooting.

Marques Coleman, 14, a student at the school told CBS affiliate WANF he was inside the classroom when the shooting happened and something in his head told him to look to his left.  “I see a kid with a, he had like a big gun,” said Coleman, who said the student just started shooting.  “I got up, I started running, he started shooting like, like 10 times. He shot at least at least 10 times.”

Coleman said he dived behind the desk and his teacher got in front of him, “My teacher started barricading the door with desks,” he said. After he got up Coleman told WANF 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.

“I just thank God that I wasn’t the one that got hit, you know, like in the midst of all of it happening. I was just thanking God because you know, he had his hands around me and stuff like that because I could have been the one that got here because I was right there. He could have easily got me. But God had his hands around me,” said Coleman.

There was a heavy police presence seen on the school’s property Wednesday morning, WANF reported at around 11 a.m. Aerial footage from the news station showed dozens of ambulances, officers and a medical helicopter gathered in the parking lot and on the green outside of the building. At that time, at least one person had been transferred into the helicopter on a stretcher and students evacuated to the school’s stadium, where buses were due to pick them up, according to WANF.

Agents with the Federal Bureau of Investigation were also called to the scene. FBI Atlanta said they were “coordinating with and supporting local law enforcement” in a statement shared just before 12 p.m. on social media.

Georgia Gov. Brian Kemp addressed the situation in a social media statement released around the same time, saying his office had moved state resources to help with the response to what he described as an “incident at Apalachee High School.”

“I have directed all available state resources to respond to the incident at Apalachee High School and urge all Georgians to join my family in praying for the safety of those in our classrooms, both in Barrow County and across the state,” Kemp said. “We will continue to work with local, state, and federal partners as we gather information and further respond to this situation.”

President Biden and his administration were aware of the shooting, the White House Press Office said in a statement.

“President Biden has been briefed by his Homeland Security Advisor, Liz Sherwood-Randall, on the tragic shooting at Apalachee High School in Winder, Georgia and his administration will continue coordinating with federal, state, and local officials as we receive more information,” the statement said.

Some 1,900 students are enrolled at Apalachee High School. Classes begin each day at 8:15 a.m., according to the district calendar district calendar.  Barrow County schools will be closed for the remainder of the week, the superintendent said.