Why was suspect in Canadian stabbing rampage on the streets?

Mark Arcand, right, who's sister Bonnie Burns and nephew Gregory "Jonesy" Burns were killed during a series of violence attacks at James Smith Cree Nation speaks to media at a press conference in Saskatoon on Wednesday, Sept. 7, 2022. Myles Sanderson, 32, and his brother Damien, 30, are accused of killing 10 people and wounding 18 in a string of attacks across an Indigenous reserve and in the nearby town of Weldon. Damien was found dead Monday, and police were investigating whether his own brother killed him. (Liam Richards /The Canadian Press via AP)

Why was suspect in Canadian stabbing rampage on the streets?