I wonder. It's really not a region that sees violent robberies, car jackings, home invasions, etc, except when someone has driven way up there trying to outrun the law. This seems awfully cold-blooded, psychopathic.
It seems very odd. If their van was broken and they stopped on the side of the road waiting for a tow truck, what are the chances that someone drove by and killed them there on the side of the road? Robbery, sure, but no reason to kill them. They look like the type of hippies who would say go ahead and take what you need, and they would be thankful for their lives and sort it out later.
The Highway of Tears killer was a transient construction worker from the USA who commuted to Northern Alberta and BC for work. Maybe this couple encountered someone like that too.