Dogs can sniff through coffee.
Drug dogs wouldn't go over every single package, though.
Does FedEx use their own drug-sniffing dogs? How likely would it be for them to be trained to sniff prescription painkillers?
A quick Googling found me the USPS's "drug packaging profile," maybe FedEx uses something similar?:
I dunno if FedEx uses a similar policy or what, but only the address, odor parts, and maybe "source state" parts really seem like strong criteria. I'm pretty sure I've sent plenty of packages that fit the other three that didn't contain drugs.
Well, the circumstances of the arrest weren't public until today so I guess no reporter would have known anything but I would think that someone working on the case would know what happened to the sender and it's a pretty important question to ask.