It is commonly publicized about the amount of illegal drugs that ARE seized at the ports of entry to the US. Obviously illegal drugs that are NOT seized, can not be directly counted. So it is difficult to directly determine the effectiveness of ports of entry inspections.
However, audit practices in the past by TSA and DHS relative to bringing guns (illegally) onto planes provided insight into the effectiveness of TSA screening. As I understand it, these audits involved having officially sanctioned officers to attempt to smuggle firearms through security. These audits were made public (often results were announced on the evening news).
So, is there a similar audit process used to rate the effectiveness of inspections for drugs that are attempted to be smuggled through ports of entry?
And if so, have those audits results ever been made public?