Jordan McGuire was released on bond last month after he pleaded not guilty to the charges.
Police believe McGuire drank alcohol with a group of 18-year-old boys in January, then performed an unwanted sexual act on one of them, who was reportedly unconscious from drinking too much.
None of those involved were high school students, but police say they're looking into more potential victims, including current Harrison students.
McGuire had resigned from Harrison and gone to South Carolina, where he was arrested in April.
No trial date has been set.