When Mathew and Isaac Auchterlonie entered the Bank of Montreal on Shelbourne Street on June 28 at 11:02am, wearing balaclavas and body armour and carrying SKS semi-automatic rifles, they had no interest in robbing the bank, according to an investigation by the Vancouver Island Integrated Major Crime Unit. Instead, motivated by anti-authority sentiment and enraged about restrictions to firearms ownership, they intended to shoot and kill as many police officers as they could. 

They ended up causing significant injuries to six officers from the Greater Victoria Emergency Response Team, before police killed them. None of the 22 hostages inside the bank were injured in the shootout.

At a press conference to announce the VIIMCU’s findings, police would not divulge or describe the evidence that they claim revealed the brothers’ motivation. They said the purpose of the investigation was to determine whether anyone had helped the brothers plot or carry out the attack. “We are now in a position to confirm that the suspects did act alone,” BC RCMP Superintendent Sanjaya Wijayakoom said. 

As the crime scene was still active, police officers went door-to-door in the neighbourhood, seemingly looking for a third suspect; one witness told Capital Daily that she had told police she believed there was a third person present during the robbery. Witnesses reported a white van driving erratically in the area around the time of the shooting; police later determined that it was the GVERT van responding to the scene.

In the aftermath of the shooting, police found more than 30 improvised explosive devices, four additional firearms, and more than 3,500 rounds of ammunition in the trunk of the brothers’ car. “Both the suspects held valid possession and acquisition licenses for both non-restricted and restricted firearms,” BC RCMP Corporal Alex Bérubé said.

Although the 22-year-old brothers had been planning “an act of extreme violence” since 2019, according to Bérubé, they were unknown to police. One of the brothers, Mathew, had been rejected from the military at some point in the interim, though a military spokesperson would not say what year he applied. The VIIMCU investigation revealed that the brothers intended to carry out their plans mid-2023 but had acted sooner because they had to move out of their home in Duncan and “having to move their arsenal would probably raise some suspicions,” Bérubé told Capital Daily.

The bank was chosen at random, according to the investigation. “Saanich wasn't a target for them,” Wijayakoom said. “They were simply trying to find a venue where they could start a confrontation with the police. And they happened to land on that bank and Saanich.”