James Allan Christians, who is 65, was picked up at a gas station in the city's southwest.
He is charged with second-degree murder, aggravated assault and possession of a weapon.
Carmel Leah Christians, who was 55, was stabbed to death and a female friend she was staying with was seriously injured in an attack on Wednesday.
Documents show Carmel Christians had gone to court to get a protection order.
She had testified at a hearing Sept. 3 that her husband punched her in the face and tried to strangle her.
She also testified that he poured gasoline in front of her and threatened to burn their house down.
She told the court that even with a restraining order, she feared for her life.
James Christians was ordered not to be within 500 metres of her.