Prosecutors and defense lawyers say Haley’s story is typical; the vast majority of illicit fentanyl — close to 90% — is seized at official border crossings. Immigration authorities say nearly all of that is smuggled by people who are legally authorized to cross the border, and more than half by U.S. citizens like Haley. Virtually none is seized from migrants seeking asylum.
You linked a report with methodology and limits, but did you read it? Traceability assumptions are, first and foremost, assumptions. To assume this agency has all required data points for some news article to claim a percentage on a number there is no way they could know, is…well I already touched on that in my first post.
I skimmed through the methodology. I’m a criminologist by training and the assumptions that aren’t based on nothing. It’s still science-based evidence.