A teenager accused of killing four people at Apalachee High School in Barrow County was previously investigated for threats about a shooting, the FBI Atlanta office said late Wednesday. Colt Gray, 14, was charged with murder after Wednesday’s shooting, according to investigators. He was not charged after an investigation last year. In May 2023, the FBI’s National Threat Operations Center received several anonymous tips about online threats to commit a school shooting, the FBI said in a statement. The threats didn’t identify a school or when it would happen, but they contained pictures of guns. Investigators tracked the post to...