Travis Baumgartner's case is due back in court Oct. 5.
He did not appear in court Friday and no date was set for his trial.
A court order had previously prevented him from talking with his mother, but she has been removed from the no-contact list.
Baumgartner, 21, was charged with three counts of first-degree murder and one count of attempted murder following the June robbery.
The Alberta Crown has elected to proceed to trial without a preliminary hearing.
Michelle Shegelski, 26, Eddie Rejano, 39, and Brian Ilesic, 35, were killed in the attack and a fourth guard was seriously injured and is recovering.
Baumgartner was the fifth man on that crew.
He was arrested a day after the robbery at the Canada-U.S. border with $334,000 in a backpack. Search warrants filed by police at the time of the shooting said that between $600,000 and $1.9 million was missing from the car.
The warrants also said his mother, Sandra Baumgartner, told officers she awoke on the morning of the shooting and found $64,000 in cash in her house and her son gone.
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