PORT ORCHARD — A 13-year-old Kingston Middle School student has been charged with third-degree rape stemming from an incident on a North Kitsap School District bus last week.

Kitsap County Sheriff’s detectives and the county prosecutor’s office are investigating the alleged sexual assault by a 13-year-old boy against a 14-year-old girl. Both are Kingston Middle School students.

A second boy, also age 13, was interviewed by police but was not arrested, but both boys have been expelled by the North Kitsap School District while the incident is investigated.

The alleged assault occurred the afternoon of March 11, but was not reported to school officials or the mother of the alleged victim until the following day.

During an investigation, a school resource officer “developed probable cause that a sexual assault occurred in the rear of the school bus, unknown to the bus driver, and that the sexual contact between one of the male suspects and the female victim was unwanted,” a NKSD spokeswoman said this week. A number of other students provided statements to the officer.

The suspect was arrested and taken to the Youth Service Center March 13, and charged in juvenile court on March 16.

Chris Case, spokeswoman for NKSD, said most students on the bus weren’t aware of the incident. The district has made counseling services available for students who witnessed the alleged incident.

On Friday afternoon, the school district released a fact sheet on the incident. Just the Facts About Bus Incident