The suspect in Canada's weekend stabbing spree that killed 10 people has died after suffering “medical distress” shortly after his arrest.
He was caught on a motorway near the town of Rosthern, in the province of Saskatchewan, after a four-day manhunt as officers responded to a report of a stolen vehicle being driven by a man armed with a knife.
The arrest took place about 100 kilometres south-west of one of the country's bloodiest acts of mass violence on Sunday.
Officers forced Sanderson’s vehicle off the road and into a ditch, Assistant Commissioner Rhonda Blackmore, commander of the RCMP in Saskatchewan, said at a news conference. He then surrendered to police.
Global News said he died shortly afterward of unspecified injuries that authorities believed were self-inflicted.
Ms Blackmore told reporters Sanderson “went into medical distress” shortly after he was detained.
Emergency medical personnel on the scene attended to him and he was taken to a hospital, where he was pronounced dead.
She did not address questions about whether he might have consumed a drug or other substance that killed him, saying the manner and cause of his death would be determined by an autopsy.
His brother and accused accomplice, Damien Sanderson, 31, was found dead on Monday in a grassy area of the James Smith Cree Nation.
Police were investigating whether Myles might have killed his brother, resulting in him sustaining an injury that required medical attention.
Ms Blackmore said an emergency caller who spotted Sanderson before his arrest indicated that he appeared to have had a visible wound.
In addition to the 10 victims killed on Sunday, 18 others were wounded in the rampage, which unnerved a country where instances of mass murder are rare.
Police said some of the victims appeared to have been on a list of targets while others were apparently random.
Authorities have offered no motive for the attacks, which occurred on the James Smith Cree Nation reserve, home to about 3,400 people, and the nearby village of Weldon, about 320km north of the provincial capital of Regina.
“We may never have an understanding of that motivation,” Ms Blackmore said, after Sanderson's death in custody.
The ten people killed in the attack:
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
Robert Sanderson, 49
Wesley Petterson, 78