A former teacher at the private, all-girls Sacred Hearts Academy sexually assaulted a 15-year-old student on two occasions, according to an indictment an Oahu grand jury returned Tuesday.

The indictment charges William E. Plourde with sexually assaulting the girl June 10 and again between June 11 and July 6. It charges Plourde with one count of first-degree sexual assault and six counts of third-degree sexual assault. The indictment also indicates the state’s intention to seek extended sentencing.

Honolulu police said they arrested Plourde, 53, at his Date Street home Aug. 7 after he called them and requested to turn himself in for having sexual contact with a minor.

Plourde remains in custody at Oahu Community Correctional Center unable to post $200,000 bail. His arraignment in state Circuit Court is scheduled for Monday.

Sacred Hearts Head of School Betty White said Plourde was fired Aug. 7 within an hour of school administrators receiving and confirming a claim against him.

Police said the girl told them Plourde, her former homeroom teacher, sexually molested her in his car in Mililani.

The girl’s parents filed for a temporary restraining order against Plourde on Friday.

Circuit Judge Richard Perkins issued an order Tuesday prohibiting Plourde from contacting the girl.