The father of the alleged teenage gunman who killed four people in a mass shooting at Apalachee High School in northern Georgia has been arrested, law enforcement officials announced Thursday night.

Colin Gray, 54, was charged with four counts of second-degree murder, two counts of second-degree murder and eight counts of cruelty to children, the Georgia Bureau of Investigation said, a day after his 14-year-old son Colt Gray was charged with murder.

The charges come after it was revealed that Colin Gray purchased the AR-15-style rifle Colt allegedly used in the massacre as a Christmas present last December.

This is a developing story. Check back for more updates.