Edwin Proctor, who had been found guilty of several charges including first degree murder, attempted murder and rape in 1995, died in custody in Saskatoon on Friday.
Proctor was 68-years-old and died of natural causes following an illness in the Regional Psychiatric Centre, a statement on the Correctional Service Canada website said.
In 1979, a 27-year-old Proctor killed 21-year-old Catherine Cluney and raped then-15-year-old Tracey Walsh and a friend near Winnipeg. Walsh has since asked the courts to remove the publication ban on her name.
He was convicted years later because he spent more than a decade in a mental health facility, after being deemed unfit to stand trial.
—With files from the Canadian Press
© 2020 Global News, a division of Corus Entertainment Inc.