Update Friday, 11:06 am:
Hawkins County Sheriff Ronnie Lawson said two teenagers created an extensive plan to kill as many students and staff as possible at Volunteer High School.
"I want you to know that this wasn't just a threat - it was a planned attack," said Lawson during a press conference Friday morning.
During a search of one of the suspect's home, investigators said they uncovered several guns, gunpowder, firecrackers, floor plans of Volunteer High School, and journals, detailing the attack.
The plans in the journals specified where to block the school's exits, how to kill the school security officers first, and research on how to kill the most people, according to Lawson.
"[The journals] studies the maximum amount of students in the lunchroom and hallways, where to block the exits, and to eliminate the SRO officer first," said Lawson.
The sheriff said the suspects even tried to recruit other students; officials have interviewed all of them.
Lawson said the mass school shooting at Columbine High School in 1999 inspired planned attack on Volunteer High School.
"He took the time to study their plan of attack, and he found their mistakes they made that he would not," said Lawson.
The 15-year-old was infatuated by serial killers and mass murders, said Lawson. The other suspect, according to Lawson, was infatuated with weapons, posting videos of military-style weapons, shot guns, and make-shift bombs detonated in Hawkins County.
The investigation into the planned attack started when a counselor contacted the Hawkins County Sheriff's Office on Oct. 25, 2013. The counselor told deputies a 15-year-old talked about his plans to kill students and staff at Volunteer High School.
As soon as the investigation began, the two teenagers weren't allowed to return to the school. Lawson said once his department got involved, the teens were no longer a threat.
"I want to reiterate, these gentlemen was never a threat to the general public or the students of Volunteer High School once this investigation started."
Director of Hawkins County Schools Steve Starnes said the school has worked closely with officials to ensure students' safety.
"We have taken on necessary precautions to ensure the safety of our students, and we'll continue to remain vigilant in our effort," said Starnes during the press conference.
Authorities charged both teens with conspiracy to commit first-degree murder, conspiracy to commit an act of terrorism, and possession of explosive components.
On Thursday, one of the suspects had a detention hearing in juvenile court. The judge set his bond at $75,000. While out on bond, the teen must be under house arrest and have full-time adult supervision.
The second suspect's hearing is set for a later date.
Right now, both teens are in state custody.
Update Friday, 8:46 am:
(WBIR) Hawkins County deputies said they'll release more details about a planned mass school shooting during a press conference Friday morning.
A source said two boys were planning a mass shooting at Volunteer High School. Officials charged both boys with conspiracy to commit first-degree murder among other charges.
The press conference will be held at the Hawkins County Sheriff's Office in Rogersville at 9:30 a.m. Friday.
WBIR 10News has sent a crew to the press conference. Tune into 10News at Noon and wbir.com for updates on this developing investigation.
The Hawkins County Sheriff says two teens are behind bars for planning a mass school shooting.
In a press release, Sheriff Ronnie Lawson says the two boys are charged with conspiracy to commit first-degree murder and other charges. A source says the charges are related to the planning of a mass shooting at Volunteer High School.
He is releasing no further details at this time, but says he will give more information at a press conference Friday morning at 9:30 am.
10News will have a crew at the press conference and will bring you more information as soon as we get it.