Myles Sanderson, 32, was the primary suspect in the mass stabbing that left 10 people dead and 18 wounded.
Sanderson had 59 prior convictions and a documented history of violence. He was released in February while serving a four-year sentence.
Only now, after the damage has been done, will Canada’s parole board review its decision to release Sanderson. “I want to know the reasons behind the decision,” Public Safety Minister Marco Mendicino said. “I’m extremely concerned by what occurred here.”