Court documents filed by police allege that in the hours after the shooting, the accused, Travis Baumgartner, left approximately $64,000 in cash on the kitchen table at the home he shared with his mother.
Baumgartner, 21, was arrested at a U.S. border crossing near Vancouver the next day. Border officials said he had $334,000 with him.
However, according to the court documents, G4S officials believe their armoured vehicle was missing between $1 million and $2 million. No one knows where the rest of the money is.
The new details are contained in information used to obtain a search warrant, which was unsealed by an Edmonton judge on Friday. They can now be made public after the court granted a joint application from CBC and the Edmonton Journal.
According to the document, Sandra Baumgartner told police that she argued with her son about rent money before he went to work that night.
Travis told her not to worry. He told her that he wasn't coming back home and that she would get her money.
When she woke up, she found a bundle of cash on the table and his work boots by the door of their Sherwood Park home.
Guards' weapons not drawn
The court document also provides additional details about what police believe happened at Hub Mall early that morning.
The G4S guards were filling an ATM just after midnight on June 15 when shots rang out.
According to the court document, a witness told police that he glanced out the window of Hub Mall and saw the armoured truck with every light blazing.
About a minute later he heard three pops in succession; then another shot after a pause. The armoured truck drove away seconds later, according to the witness.
One guard was found dead outside Hub Mall, close to where the armoured truck was parked. Three more victims, including the survivor, were found inside a small, secure room behind the ATM.
According to the court documents, the lead detective said that the positioning of the bodies led police to believe they were loading the ATM when they were shot.
Police said all four guards were shot in the head. Their guns were still in their holsters, suggesting that they had no chance to defend themselves.
Michelle Shegelski, 26, Brian Ilesic, 35 and Eddie Rejano, 39, died at the scene. Matthew Schuman, the lone survivor, continues to recover in hospital.
A former G4S armoured guard, Baumgartner faces three counts of first-degree murder and one count of attempted murder.
He is also charged with four counts of robbery with a firearm.
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