A substitute teacher at a Florida high school has been charged with sexually battering a student after a video allegedly showing one of their sexual encounters surfaced on social media, the Polk County Sheriff’s Office said. Ayanna Davis, 20, was arrested after admitting she had unprotected sex with a student four times—twice at her house and twice at his. The victim’s age is not known, but he was listed in a Polk County news release as 16 or younger.

Law enforcement is attempting to track down the video, the existence of which was reported by a student to a school administrator earlier this month after it began circulating amongst students. “I know it’s out there someplace,” Sheriff Grady Judd said, calling the encounters “a clear violation of sexual battery laws.” Davis “was in a position of influence over the victim, and she took advantage of that for her own twisted pleasure,” Judd added. Davis posted bail after making her first court appearance Saturday. She is barred from all Polk County public schools.