WOODBURY, N.J. (AP) — A former New Jersey high school teacher who secretly recorded “upskirt” videos of several female students has been sentenced to 10 years in state prison.

Adam Mayr must serve at least five years of the sentence imposed Friday before he becomes eligible for parole. The 39-year-old Washington Township, Gloucester (GLAW’-stur) County, resident had pleaded guilty to official misconduct and invasion of privacy charges.

Gloucester County prosecutors say Mayr made the videos while he was an English teacher at the Gloucester County Institute of Technology in Deptford, a vocational high school. They say at least 24 victims were identified, and most of them were about 14 years old when the videos were made.

Authorities have said they don’t believe that Mayr ever shared the videos with others.