That's in the US. What is Canada's version of the Miranda decision? Or do they have a law?
Not "to win an acquittal." Yes, people get convicted late. But in this case and this case only, it could become a sticking point. Maybe I'm jaded by O.J., but minor issues involving police became major ones, due to the general attitude that "the public" developed during the trial. People can also develop attitudes during manhunts.
Reasonable doubt can be deposited in many ways. If there really is scant evidence (and there may be - there may be no DNA, there may be no traceable weapon, only the fact that the pair were on the same highway and later committed a crime - a crime with an apparently different MO) and then, on top of that, the RCMP has not shown that there's enough on them for charges, it will mean a more drawn out trial.
And at some point, drawn out trials can be an issue. BTW, I don't know anything about Canadian juries. Do they have to be unanimous?