A red oak tree is to be planted in their honour during a service at the University of Alberta.
Relatives of the dead guards, city and university officials and representatives of the G4S security company have been invited to attend.
The three guards were working a night shift and were reloading ATM machines at the university's HUB mall when they were gunned down.
Colleague Matthew Schuman miraculously survived after being shot in the head.
A fifth guard on the crew, Travis Baumgartner, was arrested the next day at a B.C. border crossing and is to stand trial in September on charges of first-degree and attempted murder.
The victims — newlywed Michelle Shegelski, 26; rookie guard Eddie Rejano, 39, and Brian Ilesic, 35 — died at the scene.
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