The Royal Canadian Mounted Police (RCMP) said in an alert that they had "located and taken into police custody" Myles Sanderson, 30, the second suspect in a string of stabbings on Sunday that left 10 people dead and 18 injured in the James Smith Cree Nation and Weldon, Saskatchewan.
However, shortly after being taken into custody, the RCMP relayed to the media that Sanderson was pronounced dead by first responders after going into medical distress.
He had been apprehended in Rostern, about 55 miles west of Welden, the RCMP earlier said.
Myles' brother, Damien (31), who was the other suspect in the attacks, was found dead on Tuesday with stab wounds that are “not believed to be self-inflicted," according to the RCMP.
Myles is said to have an “extensive and lengthy criminal record” against property and people, according to Canadian media. He is charged with three counts of first-degree murder, one count of attempted murder and one count of break-and-enter, for the September 4 killings. However, more charges are likely to come.
The duo fled the area of the attacks in a Black Nissan Rogue SUV, although the vehicle was later erroneously reportedly spotted in Regina, a city 175 miles to the south.
The massacre was among Canada's deadliest mass killings.