(WINDER, Ga.) — As investigators worked to determine a motive behind Wednesday’s deadly school shooting in Georgia, they said they were also seeking answers about the weapon allegedly used by the 14-year-old suspect.

The shooting early Wednesday at Apalachee High School in Winder killed two students and two teachers, according to the Georgia Bureau of Investigation.

Teachers Richard Aspinwall, 39, and Christina Irimie, 53, were killed, along with students Mason Schermerhorn, 14, and Christian Angulo, 14, officials said. Nine others were injured, officials said.

The suspect, Colt Gray, a student at the school, surrendered Wednesday and was taken into custody, the GBI said. He will be charged with murder and he will be tried as an adult, the GBI said.

He was being held Thursday morning at Gainesville Regional Youth Detention Center, the Department of Juvenile Justice told ABC News’ affiliate WSB-TV.

Chris Hosey, the director of the GBI, said Wednesday night that an AR-platform-style weapon was used in the incident.

Officials said they did not yet have any answers for how Gray was allegedly able to obtain the gun to get it into the school. County Sheriff Jud Smith said that Gray was interviewed by investigators and GBI, but did not disclose further details.

A motive has not yet been determined and it is unknown if the victims were targeted, investigators said.

The FBI said on Wednesday that the Jackson County Sheriff’s Office, acting on an alert, interviewed the alleged shooting suspect in 2023.

“In May 2023, the FBI’s National Threat Operations Center received several anonymous tips about online threats to commit a school shooting at an unidentified location and time,” the FBI post read.

The FBI added, “Within 24 hours, the FBI determined the online post originated in Georgia and the FBI’s Atlanta Field Office referred the information to the Jackson County Sheriff’s Office for action.”

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