HASTINGS, Neb. (AP) — Charges have been filed against a former Hastings High School science teacher who is accused of having a sexual relationship with a student.

Court records show Johnathan Schafer was charged Monday with first-degree sexual assault of a child. According to an arrest warrant affidavit, the relationship between Schafer and the student began when she was 15 in 2012. She is now 18.

The affidavit says the 38-year-old Schafer was a friend of the victim’s family who hired her to babysit his children.

According to the document, the victim told her mother about the relationship in April 2012. Her mother then informed Hastings High School’s principal.

Schafer, who was arrested last Thursday, has posted bond and is set to appear in court May 7. It is not immediately clear if he has an attorney.