Staff Sgt. Sean Armstrong with the Edmonton police domestic offender crimes section told reporters Tuesday that family abuse is "everyone's responsibility" and doctors, neighbours and co-workers need to look for warning signs that someone might be in danger at home.
He also said there are many supports available for victims, if they really want help.
"You don't have to wait until things get out of control to contact someone," said Armstrong. "Don't wait until there's bruises and broken bones. Reach out ... There are plenty of resources to assist you, not just police."
Phu Lam gunned down seven people in his home on Dec. 28, including his wife, eight-year-old son and three-year-old niece.
Investigators have said the 53-year-old man spared two other children in the home — his one-year-old daughter and an eight-month-old nephew, and dropped them off at a relative's place the day after the massacre.
Hours later he shot a woman in another house where he was looking for someone else. He then killed himself in a restaurant in nearby Fort Saskatchewan, where he had worked as a maintenance man.
Court records show Lam's wife, 35-year-old Thuy Tien Truong, told police two years ago that her husband had DNA tests done that revealed their son was not his. He hurt her and threatened to kill her and her family, she said.
Her sister phoned police and Lam was charged with several offences. But Crown prosecutors have said several witnesses later recanted their stories and the charges were stayed. Truong had also been granted an emergency protection order against her husband but it was revoked when she failed to show up in court for a later hearing.
Armstrong said it's frustrating when victims change their minds but their decisions have to be respected.
"We do have victims in domestic violence who do want our services, so we turn our resources to those victims."
Edmonton police receive about 7,600 calls of domestic violence each year. Armstrong said while that number has remained static, the level of violence seems to be increasing.
The weekend following the mass murder, police received 15 domestic violence calls from across the city. Some involved alcohol and weapons, and in two cases there were very serious injuries, said Armstrong.
Debbie Clark with the Today Family Violence Help Centre said there was a spike in calls to her agency and others following the killings, but there is often an increase during the Christmas holidays. She said more funding and resources would help them do more work.
She hopes the crime will make everyone reflect on what they can do to combat domestic violence.
"There is help and we can each play a role in making sure that people are connected and they have supports to put a safety plan in place," she said.
"We keep our efforts focused on making sure we have the resources available for people when they need us and when they need us the most and to intervene as early as we can."