The incident occurred at Lakeland High School, about 45 minutes from Tampa, on Aug. 16 during a lockout exercise, according to a Polk County Risk Protection Order.
Police interviewed 16 students about the incident. The teacher told the students that if he was a school shooter, he would put up improvised explosive devices (IEDs), then "shoot a few rounds of ammunition and wait for everyone to hide, then hit a button and boom – everyone will die," according to the student's testimony.
The teacher also said that he would "put a bomb in the corner and put nails in it for shrapnel," another student told police.
CNN does not name the teacher as it was not charged. When interviewed by an officer, the teacher told police he was a former Marine and that his statements were a joke.
"As a former Marine, you should consider yourself a person to protect students, not make them question whether their teacher wants to harm them," Detective Justin Konacer, who filed the risk protection order, wrote in his report .
Police search the teacher's home and vehicle but no weapons were found, court documents say.
The teacher has no criminal history, but a temporary ex parte risk protection order says the teacher "may be severely mentally ill or having recurring mental health problems health. "
The Polk County School says the teacher is on administrative leave while investigating the case. Jacqueline M. Bird in the school district superintendent says the district" cooperates fully with law enforcement investigations and conducts our internal investigation . "
" Every day, Polk County Public Schools are entrusted with the lives of more than 1
The teacher is due in court on August 30 for a hearing. on a definitive risk protection order.
Jamie Lynch and CNN's Tina Burnside contributed to this report.