A coach and teacher at Lithia Springs High School was arrested for having sexual contact with a 17-year-old female student.

Douglas County Sheriff Phil Mill told Channel 2 Action News the student said her and Dennis Brown were sending text messages to each other. The student told investigators the texts started to get sexual and the two met at a the Lithia Springs Park and Ride on Lee Road in September.

The teen told investigators her and Brown did engage in a sex act during school hours, in a parking lot away from campus.

"He always had his phone out and everything, and if you went up to his desk he'd hide everything. We weren't really surprised," student Chelsea Wentworth said.

Wentworth says the female student involved had been bullied recently.

"There's been posters made about this girl, around the school, saying that she shouldn't be here and all this because she got him fired," Wentworth said.

Authorities were tipped off by a third-party who suspected Brown was having an inappropriate relationship with at least one student.

A school representative said Brown resigned from his position at the school. Brown is charged with custodial sexual assault.