Des Moines, IA – The owner of a private, for-profit boarding school for teens in Iowa allegedly forced girls to undress during “body image therapy” sessions.

Benjamin Trane, 39, was charged Friday with third-degree sexual abuse, sexual exploitation by a counselor and child endangerment, according to the Associated Press. He turned himself in Thursday after he was the focus of 19-month investigation into allegations of abuse.

Over 100 students from mostly well-off families across the nation were enrolled in Midwest Academy, which closed in 2016, according to WGEM.

Division of Criminal Investigation special agent Joe Lestina claims that Trane abused his power.

According to the AP report, Trane performed multiple sexual acts on one student in 2015, “in order for her to successfully participate and ‘level up’ in the program and to be able to contact her family member.” Shockingly, Trane would allegedly hold both one-on-one and group counseling sessions with female students, in which they undressed for “body image therapy.”  Trane would then engage sexually explicit conversations with those students and touch them “for the purpose of sexual arousal, gratification and attempted grooming,” Lestina wrote in criminal complaints released on Friday.

Lestina also claims that Trane kept other students in isolation for days or weeks at a time. Some former students told the AP that they were forced to stay in concrete “isolation boxes” for days or weeks at a time until they were able to maintain a specific posture for 24 hours.

A former employee of the academy, 34-year-old Nathan Teggerdine, told the Des Moines Register, that one boy was put in an isolation room for 47 days. Teggerdine said that teen was sent to the private school by his mother after he began acting out in the wake of his father’s suicide.

Trane faces up to 12 years behind bars.