Calgary police have charged a teacher with the alleged sexual assault of a teenage girl more than 20 years ago.

In a Monday news release, CPS said the victim, who is now an adult, came forward in 2023.

She reported multiple instances of sexual assault between 2000 and 2003 when her teacher began an inappropriate relationship with her.

Police believe the assaults started when the victim was 14 years old, as a student at École Sainte-Marguerite-Bourgeoys, and continued for several years.

“It is believed the teacher used his position of trust to befriend the victim and develop an ongoing sexual relationship with her,” CPS said in the release.

“Several of the assaults are believed to have taken place in his vehicle and at his residence.”

Police have charged Mario Joseph Denis Arsenault, 54, of Levis, Que., with two counts of sexual exploitation and one count of sexual assault.

He is scheduled to appear in court on June 6.

“It takes immense courage for victims of sexual assault to come forward to police, especially when they experience exploitation by someone whom they trust,” said Staff Sgt. Tom Hanson of the Calgary Police Service sexual assault investigations unit.

“Young people cannot give free and informed consent for any sexual activity with a person in a position of trust and authority over them, regardless of whether they say they agree to it or not.”

In a statement, FrancoSud, Calgary’s Francophone school board, said it is “deeply shocked and saddened” by the allegations.

“This teacher worked at Sainte-Marguerite-Bourgeoys School from 2000 to 2017 and the offences took place from 2000 to 2003,” the statement reads.

“We thank the Calgary Police Service for their dedication and ongoing work to charge and arrest this individual, who is currently residing in Quebec.”

Anyone with information about this incident is asked to contact police by calling 403-266-1234. Tips can also be submitted anonymously through Crime Stoppers .