The 14-year-old charged with murder in the shooting at a high school in Georgia had shown interest in prior mass shootings, particularly the 2018 massacre at Marjory Stoneman Douglas High School in Parkland, Florida, according to two senior law enforcement officials briefed on the investigation.
The information came as a result of the searches conducted in the investigation.
Separately, according to newly released documents, law enforcement officials who last year interviewed the teen did not arrest him then because they could not tie him to an online account that had made threats to carry out a school shooting
The teen fatally shot four people — two teachers and two students — on Wednesday at Apalachee High School in Winder on his first full day as a new student there, authorities said. He has been charged as an adult. Winder is in Barrow County, about 50 miles northeast of Atlanta.
Get top local stories in Philly delivered to you every morning. >Sign up for NBC Philadelphia's News Headlines newsletter.
According to the investigative documents, the FBI received a tip in May 2023 from a user on Discord, a chat platform popular with online video game enthusiasts, about online threats to commit a shooting at a middle school. The FBI traced the Discord account to a person with the same name as the teen’s father and referred the case to the sheriff’s department in Jackson County, where the teen was enrolled at Jefferson Middle School.
The sheriff’s office interviewed the teenager and his father, who said he wasn’t familiar with Discord and did not play video games. The teen told the sheriff’s office that he once had a Discord account but had deleted it. The teen denied making any online threats and “expressed concern that someone is accusing him of threatening to shoot up a school, stating that he would never say such a thing, even in a joking manner,” the documents state.
The local authorities ultimately “cleared” the case because the FBI tip was inconsistent with the information discovered during their investigation, according to the documents.
Among the inconsistencies, according to the documents, was that the Discord account was associated with the teen’s email address, but the phone number on the account did not match the teen’s.
The account was traced to a series of possible IP addresses in Buffalo, New York, and in other parts of Georgia, including Fort Valley and Statesboro, where the teen had not lived, according to the investigative report.
The user’s profile name was written in Russian and translated to the last name of a school shooter. The teen’s father told an investigator that neither he nor his son spoke Russian, the report said.
The teen said he was not active on Discord at the time the threat was made and had stopped using it because his account had been hacked multiple times “and he was afraid someone would use his information for nefarious purposes,” according to the report.
The law enforcement official told the teen’s dad that he could not substantiate the tip from the FBI or that the father or son was behind the Discord account that made the threat. The case was then cleared, but Jackson County authorities “alerted local schools for continued monitoring of the subject,” the FBI said Wednesday.
It is not clear whether Barrow County schools were also aware of the investigation or were “monitoring” when the teen enrolled there last month.
Barrow County Sheriff Jud Smith said Thursday that the teen was new to Barrow county schools, having enrolled two weeks ago. Wednesday was his second day at Apalachee High School and his first full day, Smith said.
In an interview with NBC News on Thursday, Smith said the sheriff’s office learned about last year's investigation on Wednesday, about two hours after the shooting.
Smith said he was confident that the previous tips had been investigated properly by the FBI and local law enforcement.
“Local authorities went to the house, interviewed him, interviewed his father, they did a report, they did what they were supposed to do, and found that there was no proper cause” to arrest him, Smith said. “Regardless of the situation, all of us have civil rights. He didn’t commit a crime. He made a comment. It was unfounded at the time.”
But Isaiah Hooks, 15, a football player at the high school said it was difficult to swallow news that some authorities were aware of and monitoring the teen.
“It’s even harder just to think of, to accept, that somebody that could have done this when the FBI knew who he was, that he was capable of this. I lost my coach and classmates and friends who were hurt right across from the room I was in,” Hooks said. “I just feel like that person shouldn’t have been able to even be around a school. His threat should have been included in his transcript or something. This should have been prevented since they knew he could do something like this.”
This story first appeared on NBCNews.com. More from NBC News: