MONTREAL -- Montreal police are trying to determine who mailed a powdery substance to murder suspect Luka Magnotta.
But they say the substance found in an envelope was not dangerous, but yesterday's discovery prompted authorities to shut down one of Canada's biggest postal centres.
Magnotta is facing multiple charges, including first-degree murder, in the death and dismemberment of Montreal student Jun Lin.
The 29-year-old has pleaded not guilty to all counts.
Two postal workers and two managers were treated for what the local union chief called "adverse psychological reactions."
