An 18-year-old Oklahoma man charged with raping a 16-year-old former high school classmate is scheduled to face a judge.

Tristen Kole Killman-Hardin is set for arraignment Wednesday on two counts of first-degree rape.

Killman-Hardin was arrested and charged Tuesday in a case that sparked a protest at Norman High School over how administrators handled allegations that alleged victims were bullied.

Police say they are investigating rape allegations by at least two other girls, and Cleveland County District Attorney Greg Mashburn said additional charges are "an open possibility."

Police say the 16-year-old was assaulted the night of Sept. 19 after Killman-Hardin offered to give the girl a ride home from a gathering of friends where she'd been drinking.

Court records don't indicate whether Killman-Hardin has an attorney.