I had a young relative I chased around to try and get clean for years before he OD'd on opioids in a bay area Air BnB with his girlfriend. He would order laminated 'diving certificates' with drugs encased in them by mail, and other postal deliveries that were clearly really drug shipments. There is little reason for mules when 18 wheelers are bringing in hidden drug shipments from Mexico and the postal service are delivering deadly drugs from India as was the case with the San Jose police union dealer.