Correct, they hadn't charged them by the time they found their bodies, but they had enough ballistics and other evidence to name them as suspects. This gave them "probable cause" which allowed RCMP to get search warrants, etc. necessary to gather more information and evidence in order to apprehend them.
The killers already had quite a head start by the time RCMP discovered they were linked to all 3 murders. Autopsies and evidence testing were still incomplete by the time they reached Manitoba, IIRC. Preliminary autopsy results for Mr Dyck weren't ready until the 23rd, the same day the killers were spotted in Gillam.
JMO, it was surprising to see they still had so much ammo at the end. Everyone was speculating about why the killings stopped, assuming they had run out of ammo.
Question for any locals here: Was their plan to make their way to Hudson Bay and commandeer a boat or ship to go elsewhere realistic? Of course their plan to go down the Nelson River was ill conceived, but is there much ship traffic in the Hudson Bay? It doesn't look like it. They would have needed to go to the Port of Churchill
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