Hillsborough County Sheriff's deputies arrested 50-year-old Mark Ackett -- a fashion design teacher at a Florida high school -- on Sept. 11.
The arrest came after a Bloomingdale High School student discovered two cell phones hidden in the changing area of the classroom where students disrobed for assignments.
According to authorities, deputies also found three cameras and thumb drives in Ackett's desk.
However, the case just got bigger.
Ackett turned himself back in Monday on 353 additional charges of video voyeurism and pornography.
He's being held on a $2 million bond.
Local news outlets report that Ackett told investigators he began recording students in January 2017. He also coached the girls' volleyball team.