A former coach and teacher at a Marion County military school who was found guilty of having sex with a 15-year-old girl was sentenced to 80 years in prison Tuesday.

In October a jury found Duane Adams, 55, guilty on four counts of sexual battery.

Adams, a former athletic director at Francis Marion Military Academy, was arrested in January after Ocala police said they found a student from the school had been staying at his apartment.

At first, police said Adams denied having a sexual relationship with the teen, but both he and the girl later admitted to having sex on multiple occasions.

Police said Adams even told them he and the 15-year-old exchanged rings and vows in a private ceremony and were married.

In order to be legally married in Florida, anyone younger than 16 must obtain a marriage license from a county judge, with or without parental permission.

Adams' most recent, valid marriage license was to a woman his own age in 2011. The couple divorced in December.

Adams was fired from Francis Marion Military Academy following his arrest. During his tenure as the school's athletic director, he coached teams to back-to-back national championships in orienteering, a sport centered on navigational skills using a map and compass.