The Saskatchewan Coroner's Service and Saskatchewan Royal Canadian Mounted Police provided names and ages of the victims in a statement Wednesday but declined to confirm the relationships between them. Six of the victims share the last name Burns, two share the last name Head, and one shares the last name of the two suspects in the attacks.
Petterson is from Weldon, Saskatchewan, while the other nine victims are from James Smith Cree Nation.
Several family members of some victims spoke at a press conference Wednesday about their loved ones. Saskatoon Tribal Chief Mark Arcand identified Bonnie Burns as his sister and Gregory Burns as her son, and he said another of her sons was stabbed but survived.
"Let me be honest in saying this, we don't really know what happened. We just know that our family members were killed in their own home, in their yard," Arcand said.
In addition, 18 people were injured in the stabbing attacks, but authorities will not be releasing their identities. "We can confirm one young teen was injured and the remaining injured are all adults. We will not be confirming other specific ages," the agencies said.
Police have warned that Myles Sanderson may be injured. He is wanted on a warrant for three counts of first-degree murder, one count of attempted murder and breaking and entering into a residence.
Police on Tuesday reported a potential sighting of Sanderson at the James Smith Cree Nation, but police later determined he was not in the community. The search has expanded to the entirety of the province of Saskatchewan, authorities said.
Some of the victims were apparently targeted, police say
It remains unclear what motivated the violence and how or whether the brothers knew any of the victims.
Some were apparently targeted while others may have been attacked randomly, Royal Canadian Mounted Police Assistant Commissioner Rhonda Blackmore said in a Monday briefing.
It's also unknown if the brothers carried out the attacks at the same time, according to Blackmore.
The first stabbing was reported on the James Smith Cree Nation at 5:40 a.m. local time. Minutes later, several more calls came in about stabbings at other locations, police said.
The nation has a population of around 3,400 people with about 1,800 members who live on the reservation, according to its website.
By 9:45 a.m., authorities were reporting victims in multiple locations, including one in Weldon.
Lydia Gloria Burns, a first responder, was responding to a crisis call when she was caught up in the violence and killed, her brother Darryl Burns told Reuters, though the agency didn't say if the call was related to the stabbings.
"She was butchered," her brother Ivor Burns said to Reuters.
The discovery of Damien Sanderson's body a day after the attacks also raised questions about his brother's involvement in his death. But police said Monday that it was unclear if Myles Sanderson was involved.
"It is an investigative avenue that we are following up on, but we can't say that definitively at this point," Blackmore said.
Suspect had a 'lengthy' criminal history and was released by parole board
Myles Sanderson was described as being approximately 6 feet 1 inch tall and weighing about 240 pounds, with brown hair and brown eyes. Police on Tuesday released an updated photo of him.
Blackmore previously said that Sanderson had warrants out for his arrest before the stabbings.
"Myles' record dates back quite a number of years and it includes both property and persons crimes," Blackmore said, without elaborating on the alleged crimes.
"His actions have shown that he is violent and so we're continuing to emphasize for people to remain vigilant," Blackmore added.
Sanderson was granted statutory release by the Parole Board of Canada, according to a ruling made on February 1, 2022.
Statutory release is a presumptive release by law that allows an offender to serve part of their sentence in the community under direct supervision, according to the board. By Canadian law, the Correctional Service of Canada must release most offenders with supervision after they have served two-thirds of their sentence, if they have not already been granted parole, except for those serving a life sentence.
The board said in the ruling that it didn't believe Sanderson would present a risk to the public if released. The decision did note his long criminal history and that he was assessed by a psychologist for a "moderate risk of violence."
"Your criminal history is very concerning, including the use of violence and weapons related to your index offences, and your history of domestic violence which victimized family, including your children, and non-family," the ruling states.
In a statement, the Parole Board said it "extends its thoughts to the victims, their families and all those who have been impacted as a result of these senseless and horrific acts of violence."
Citing the Privacy Act, the board said it could not discuss specifics of an offender's case.
CNN's Paula Newton, Tina Burnside, Chuck Johnston, Michelle Watson and Cara Lynn Clarkson contributed to this report.