Toronto police have arrested Shayne MacDonald, who was the subject of a Canada-wide warrant after the fatal stabbing of his aunt in west-end Toronto Friday night.

Police at 14 Division confirmed the 21-year-old is in custody at the station.

Officers arrived at the home of Sarah Vermelhudo — MacDonald's aunt — in the College Street and Dufferin Street area on Friday night and discovered the 38-year-old woman with serious stab wounds. A second woman, Vermelhudo's 59-year-old mother, also sustained serious stab wounds.

Both were taken to hospital but MacDonald's aunt succumbed to her injuries. Her mother is expected to recover.

Sarah Vermelhudo, 38, is dead following a double stabbing on Friday night in Toronto's west end. (Facebook)

The accused did not turn himself in, a police spokesman said Monday. Instead, officers credit the public for providing information that led to MacDonald's arrest.

MacDonald is facing a second-degree murder charge in the death of his aunt, Sarah Vermelhudo, and an attempted murder charge in connection with the stabbing injuries of Maria Vermelhudo.

He is scheduled to appear at the Old City Hall courthouse Tuesday morning.

Matthew Martin, who describes himself as a close friend to MacDonald, said he met MacDonald in elementary school and the two had remained in contact for over 10 years. He learned of the stabbing Saturday morning and was in disbelief.

"I didn't believe it," he said. "All of this is a complete shock to us."​