Canada has long been very proud of the longest undefended border in the world. In comparison with the border in the south of the United States, which is a much more militarized border, it seems much more likely that they would catch a lot more fentanyl coming from the southern border than from the northern border.
Is there any way to determine the provenance of fentanyl? I'm wondering if there's a chemical compound such that you could say, “This fentanyl originated from here”, or if it's chemically the same regardless of the provenance or the jurisdiction it came from.