Why is he in jail then?
I think the issue is, despite the fact she's 17, the affair began before she was of legal age...and he can get nailed for that.
In Hoc.
All I have to go on is the article which states: "Police filed charges of inappropriate behavior between an educator and a student".
Sounds to me like there's a particular state law he's being charged under that doesn't necessarily involve sexual conduct with someone under the age of consent. Perhaps a law also applicable to college profs & university students. I could, of course, be wrong.