Saanich police confirmed Friday that the couple found dead in their Cadboro Bay home this week were victims of a murder-suicide, but officers refused to say who was responsible for their deaths.

Police confirmed the victims were husband and wife Erich Mueller, 72, and Kathy Mueller, 66, who lived in the beachfront home at 3931 Cadboro Bay Rd. for 10 years.

Autopsies conducted Thursday by the B.C. Coroners Service in Vancouver confirmed the deaths were a murder-suicide.

Police spokesman Sgt. Dean Jantzen said there is "no history of any police contact whatsoever" with the Muellers.

However, he added: "It is believed by both investigating detectives and family members that mental health issues may have been a contributing factor in this incident."

Jantzen would not elaborate about what type of mental health issues the Muellers might have had. Nor would he release information on their cause of death, when they died, or what kind of weapon was recovered from the home. He said he was unaware whether there were firearms in the home.

Jantzen said investigators know who is responsible for the murder-suicide but would not say who it was. It is typical for police departments to disclose who they believe is responsible for a crime.

"Those intimate details are not being released by us," he said. "It's not a crime, this is a family tragedy."

In the days after his parents' bodies were found, their son Tien Mueller said the two were "happily retired" and told the Times Colonist: "My parents were not suicidal."

The couple spent Christmas with their daughter in Abbotsford and hosted a friend from Terrace at their Saanich home from Dec. 28 to Jan. 5. Frances Birdsell said Erich was depressed at times, which worried his wife. But Erich did not seem depressed during her visit, Birdsell added.

The couple were found dead by their son-in-law Martin Hickman around 3 p.m. Tuesday.

Erich and Kathy Mueller have been characterized by family and friends as a well-off couple who loved their three children and six grandchildren, and were spending their retirement travelling the world.

Jantzen said family members were briefed by investigators Thursday evening and are asking for privacy.

Speaking for the family, Dan Stefanson, the couple's son-in-law, declined to comment further, saying it "is a family matter."

Friends said Erich was a quiet man and a skilled civil engineer who, at one time, worked in the planning department of the city of Prince George. Kathy was a teacher who taught in China and most recently in a remote B.C. First Nations community near the Alaskan Panhandle.

kderosa@timescolonist.com

Watch a video of the crime scene