Courtney Struble's disappearance is now being investigated as a homicide, as opposed to a missing person case.

Courtney hasn't been seen since July of 2004. She finished watching a movie with friends and declined a ride home. She was last seen walking along Highway 39 on the western outskirts of the city.

She was 13 at the time.

The RCMP Historical Case Unit was tasked in 2009 with taking over the case from the Estevan Police Service and the Missing Children's Society of Canada. Corporal Robert Zentner from the RCMP unit said they studied all the information compiled by the other agencies during their investigations, and then decided that they were dealing with a murder case.

"We have had an opportunity to … listen to all of the statements, and piece together the events that were taking place at the time that Courtney disappeared," said Zentner. "From there, based on obviously our experience in working with other missing persons or homicide cases, we believe, obviously, that something bad happened to Courtney Struble on the night she disappeared."

Zentner couldn't reveal the specifics from the investigation, nor could he state if they have any suspects in the case.

Information on Courtney's disappearance arrived at the Historical Case Unit in the fall of 2009. The unit then had to gather data from the Estevan Police Service and the Missing Children's Society of Canada. The information then had to be re-organized into the RCMP's major case management system that is used for such incidents.

Zentner said they have been actively investigating the case for eight to 10 months, and the investigation remains open.

"We're actively following up on information provided by the public, as well as conducting interviews or re-interviews, depending on the circumstances," said Zentner. "We've been down to Estevan on numerous occasions, and spoken to members of the public there, as well as at other locations in Canada."

Tips have continued to come in from the public, he said. When they sent out a press release last year near the sixth anniversary of Courtney's disappearance, they received phone calls from people who claimed they had seen her, or that they had details on the case. Tips have come from current and former Estevan residents, and from people across Canada who haven't lived in Estevan.

Zentner said the Historical Case Unit will continue to visit Estevan to speak with people in the community, including Courtney's family and friends, as part of their investigation.