In a historic move, the father of a 14-year-old suspected of fatally shooting four people and injuring nine others in a Georgia school has been arrested, raising more questions about accountability in such tragedies.

Colin Gray, the 54-year-old father, faces the most severe charges ever filed against a parent of an alleged school shooter: four counts of involuntary manslaughter, two counts of second-degree murder, and eight counts of cruelty to children, according to the Georgia Bureau of Investigation (GBI).

“These charges stem from Mr. Gray knowingly allowing his son Colt to possess a weapon,” Chris Hosey, director of the GBI, said during a news conference.

Colt Gray, the 14-year-old son charged with four counts of murder, is accused of using a semiautomatic assault-style rifle to kill two students and two teachers on Wednesday at Apalachee High School in Winder, about 50 miles northeast of Atlanta.

Officials identified the two students killed as Mason Schermerhorn and Christian Angulo, both 14. The two teachers were Richard Aspinwall, 39, and Cristina Irimie, 53. Nine people were injured, including seven students, all of whom are expected to make a full recovery.

Law enforcement officials and family members noted warning signs before Wednesday’s attack. A year ago, local investigators interviewed Gray and his son about alleged online threats the teen had made to shoot up a school, which Colt denied. This week, the boy’s aunt, Annie Brown, told The Washington Post that the teen had been “begging” the adults around him for mental health support in recent months.

Before Thursday’s announcement, the teen’s grandfather, Charles Polhamus, expressed his belief that Colin should be charged along with his son. “If he didn’t have a damn gun,” Polhamus said, “he wouldn’t have gone and killed anybody.”

Barrow County District Attorney Brad Smith clarified the charges against Colin on Friday, explaining that “Second-degree murder is different in Georgia than in other states. It’s a relatively new charge specifically geared toward cruelty to children in the second degree. If you commit cruelty to children in the second degree that causes death, that is second-degree murder,” he told CNN.

These charges come five months after Michigan parents Jennifer and James Crumbley became the first in the U.S. to be convicted in connection with a mass school shooting. They were sentenced to at least 10 years in prison for failing to secure a firearm at home and acting indifferently to signs of their son’s deteriorating mental health before he killed four students in 2021.