ROSTHERN, Saskatchewan >> The last suspect in a horrific stabbing rampage that killed 10 and wounded 18 in western Canada is dead following his capture, but how he died after being taken into custody has prompted fresh investigations.

One official said Myles Sanderson, 32, died from self-inflicted injuries Wednesday after police forced the stolen car he was driving off a highway in Saskatchewan. Other officials declined to discuss how he died .

“I can’t speak to the specific manner of death. That’s going to be part of the autopsy that will be conducted,” Assistant Commissioner Rhonda Blackmore, commander of the Royal Canadian Mounted Police in Saskatchewan, said at a news conference Wednesday night.

The other suspect, Sanderson’s 30-year-old brother, Damien Sanderson, was found dead Monday near the scene of the bloody knife attacks inside and around the James Smith Cree First Nation reserve early Sunday. Both men were residents of the Indigenous reserve.

Blackmore said Myles Sanderson was cornered as police units responded to a report of a stolen vehicle driven by a man armed with a knife. She said officers forced Sanderson’s vehicle off the road and into a ditch. He was detained and a knife was found inside the vehicle, she said.

Sanderson went into medical distress while in custody, Blackmore said. She said CPR was attempted on him before an ambulance arrived and he was taken to a hospital, where he was pronounced dead.

“All life-saving measures that we are capable of were taken at that time,” she said.

Blackmore gave no details on the cause of death. But an official, who spoke on condition of anonymity, earlier said Sanderson died of self-inflicted injuries, without elaborating.

Video and photos from the scene showed a white SUV alongside the road with police cars all around. Air bags had deployed in the SUV. Some photos and video taken from a distance appeared to show Sanderson being frisked.

Members of Saskatchewan’s Serious Incident Response Team went to the arrest site and will review Sanderson’s death and police conduct.

The federal public safety minister, Marco Mendicino, also stressed that the events will be investigated.

“You have questions. We have questions,” he told reporters during a Cabinet retreat in Vancouver, British Columbia, adding: “There will be two levels of police who will be investigating the circumstances of Myles Sanderson’s death.”

Mark Mendelson, a former Toronto police detective, said the police are bound by police service laws that govern the work of internal affairs when there is a death in police custody. Mendelson said police can’t comment yet on how the interaction took place or on what the officers saw or what he said to them.

“They have to at least wait until the forensic autopsy is concluded and hopefully the pathologist will come up with a cause of death. If it’s drugs, then toxicology is going to take sometime,” he said. “If it’s a stab wound that didn’t leak through his clothes then we should hear that. Everybody wants answers.”

His death came two days after the body of Damien Sanderson was found in a field near the scene of the knife rampage. Police are investigating whether Myles Sanderson killed his brother.

Darryl Burns, who lost his sister Gloria Burns to the attack, hugged Damien Sanderson’s widow at a news conference Wednesday, telling her that the family was ready to forgive.

“Damien was caught up in the life,” Darryl Burns said. “He was caught up in a moment. But hearing the stories of Damien. He tried to stop it, he tried to stop it, but he paid with his life.”

Sobbing, his widow muttered, “That’s not my husband.”

Chief Robert Head of Peter Chapman Band said the community was like a “war zone” in the immediate aftermath of the attack. He said four helicopters were swooping down to transport the wounded and dying to medical treatment.

“Right now, we still have 14 families that are in the hospitals there,” he said, noting that one of his first cousins was among the dead.

Blackmore said that with both men dead, “we may never have an understanding of that motivation.”

But she said she hoped the families of the stabbing victims will find some comfort “knowing that Myles Sanderson is no longer a threat to them.”

The stabbings raised questions of why Myles Sanderson — an ex-con with 59 convictions and a long history of shocking violence — was out on the streets in the first place.

He was released by a parole board in February while serving a sentence of over four years on charges that included assault and robbery. But he had been wanted by police since May, apparently for violating the terms of his release, though the details were not immediately clear.

His long and lurid rap sheet also showed that seven years ago, he attacked and stabbed one of the victims killed in Sunday’s stabbings, according to court records.

Tribal leaders at the news conference criticized the decision to release Myles Sanderson back into the community.

“The system itself is broken,” said Chief Wally Burns of James Smith Cree Nation. “The parole board let this young fellow out, this young man. And they didn’t notify any of our community members or our leadership or even our local detachment. All that we knew was that after the fact. This tragedy could have been avoided.”

The leaders declined to answer questions on the crime itself but called for more resources for mental health and substance abuse services and more control to police themselves.

Mendicino, the public safety minister, has said there will be an investigation into the parole board’s assessment of Sanderson.

“I want to know the reasons behind the decision” to release him, Mendicino said. “I’m extremely concerned with what occurred here. A community has been left reeling.”

The Saskatchewan Coroner’s Service said nine of those killed were from the James Smith Cree Nation: Thomas Burns, 23; Carol Burns, 46; Gregory Burns, 28; Lydia Gloria Burns, 61; Bonnie Burns, 48; Earl Burns, 66; Lana Head, 49; Christian Head, 54; and Robert Sanderson, 49. The other victim was from Weldon, 78-year-old Wesley Patterson.

Authorities would not say if the victims might be related.

Court documents said Sanderson attacked his in-laws Earl Burns and Joyce Burns in 2015, knifing Earl Burns repeatedly and wounding Joyce Burns. He later pleaded guilty to assault and threatening Earl Burns’ life.

Many of Sanderson’s crimes were committed when he was intoxicated, according to court records. He told parole officials at one point that substance use made him out of his mind. Records showed he repeatedly violated court orders barring him from drinking or using drugs.