Jared Cano, 17 was arrested on Tuesday night after someone tipped off police about the "catastrophic" plot.
Police say it appears the teen was planning to kill about 30 people at Freedom High School in north Tampa next week. He was allegedly going to detonate several bombs and kill administrators and any student that got in his way.
When they searched his bedroom, they found bomb making materials, including a fuel source, shrapnel, plastic tubing and timing and fusing devices, and a manifesto detailing his plan minute by minute.
Cano has a lengthy juvenile record, which includes burglary, altering serial numbers on a firearm and drug possession. He was expelled from Freedom High School a year and half ago for carrying a concealed weapon.
Records show that all the juvenile charges filed against Cano in the past have been either dismissed, or no action has been taken.
Cano now faces felony charges of possessing bomb-making materials, threatening to throw, project, place or discharge a destructive device, cultivating marijuana, possession of drug paraphernalia and possession of marijuana.
Prosecutors say Cano had repeated his plans to set off bombs at school and kill people at the time of his arrest. He even tried to speak in court on Wednesday at a hearing, but he was quickly hushed by his public defender.
The Associated Press contributed to this report.