An Oahu grand jury returned an indictment Thursday charging a fired Sacred Hearts Academy history teacher with sexually assaulting two girls when they were his students.

The indictment charges Mario DiLello, 55, with felony sexual assault for allegedly placing his hand on a then 14-year-old student’s buttock at the all-girl Catholic school in May 2016. The indictment also charges DiLello with misdemeanor sexual assault for allegedly placing his hand on the buttock of a 16-year-old student Sept. 19.

Deputy prosecutor Ayla Weiss told State Circuit Judge Colette Garibaldi that DiLello has no prior arrests or convictions in Hawaii, but has a felony drug conviction in New York.

Garibaldi confirmed bail for DiLello at $50,000.

In a letter sent to school alumnae Oct. 13, Head of School Betty White said the Kaimuki school fired DiLello after it received reports of inappropriate behavior from two high school students. She said the school notified authorities and that the parents filed police reports.

Honolulu police arrested DiLello on Tuesday at his Moiliili condominium. He appeared Thursday morning in Honolulu District Court and remains in custody unable to post bail.