Sources said 53-year-old Phu Lam did maintenance work at the VN Express Asian restaurant in Fort Saskatchewan, a bedroom community northeast of Edmonton.
Police found Lam's body in the restaurant early Tuesday, dead by his own hand, following the killings in Edmonton on Monday.
Huong Tran said Lam was the ex-husband of her mother-in-law, an owner of the eatery, and that as an employee he had a key and access to the building after hours. Tran declined further comment.
Police have yet to publicly identify the suspect and have only said the man who killed himself in the restaurant had a business interest in the place. Police said he had a criminal record involving drugs and violence dating to 1987 and that he used a stolen handgun in the murders.
Despite the killer's criminal past, police have emphasized there is nothing to suggest the slayings were anything other than a "planned and deliberate" act of domestic violence.
The first victim was a woman in a home in southwest Edmonton.
Police said a man entered the house just before 7 p.m. Monday and opened fire before fleeing. When officers arrived, they found 37-year-old Cyndi Duong dead.
An hour and a half later, officers responded to reports of a suicidal man at a northeast residence. Family members reported in the call that the man was "depressed and over-emotional."
When officers arrived, no one answered the door. And when they searched the exterior of the home, they found nothing overtly suspicious and didn't have enough evidence to force themselves inside.
Hours later, after police were contacted by a second person who had more information, they returned to the residence and found the carnage. Two men and three woman between the ages of 25 and 50, and a girl and a boy — both under the age of 10 — were dead.
Police then tracked to the restaurant a black Mercedes SUV seen at the first shooting. Tactical officers rammed their way inside and found the body of the killer.
Investigators were waiting for autopsy results scheduled for New Year's Day to positively identify the shooter and the victims, other than Duong. They have not confirmed the relationships of any of those involved.
"It's just so awful," said Heather Ratsoy, owner of It's All About Kids daycare, who looked after Duong's three children until 2011.
When she heard the tiny woman with a bubbly personality had died in the mass murder, Ratsoy said she couldn't believe it.
Duong was married with three children, two boys 14 and 10, and had an eight-year-old girl. Ratsoy said she's concerned for the kids.
"You start thinking, was she killed in front of her children? Was the dad there?
"These are the answers we don't have."
Duong's Facebook page indicates she had worked at Enbridge and attended Beulah Alliance Church. Associate pastor Darren DeGraaf wouldn't comment other than to say the church has "profound grief at the senseless act of violence which took the lives of Cyndi" and the other victims.
Records show the shooter owned the home at the centre of the second crime scene, where the seven bodies were found. Neighbours there reported that in the past they had seen and heard a couple fighting there. Police said they had been called to the residence twice before and, in 2012, had laid charges of domestic and sexual assault.
Outside the home Wednesday, a memorial of stuffed animals, candles and flowers grew, while public figures paid their respects, including Edmonton Mayor Don Iveson.
"The scale of these events is rare and exceptional," Iveson said in a statement. "However, domestic violence remains all too common in our society and this tragedy is a harsh reminder of the continuing need for support for individuals and families in crisis, and the critical importance of reporting any instances of domestic violence to police.
"I would encourage anyone who is struggling to cope this holiday season to reach out to friends and family for support."
In 2013, Alberta had the second-highest rate of self-reported spousal violence in the country, according to the provincial government.
Alberta's Family Violence Death Review Committee, operational for a little over a year, has the responsibility of reviewing domestic violence cases and making recommendations to government to prevent future deaths.
Chairman Allen Benson expects the mass murder will be reviewed by the group.
"I would see this not just as something the review committee would want to review, but ... I would think the public would want answers," Benson said.
"What could have been done to prevent the deaths from occurring? What interventions might have been in place or could have been in place to prevent the deaths? We would look at all of those factors."
— With files from CHED
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