I work for the USPS, and the only thing I can say is that the chances of the culprit being the postal worker are slim to none. For the simple following reasons. If it was a mail handler who did it, the package would have been put into a plastic bag that read something along the lines of this mail has been found in this condition....blah blah blah. If it was the carrier, the package would have never reached its destination. Once a package or envelope has been opened or reported tampered with, that carrier will then be watched very closely by postal inspectors. It's easy for a carrier to say the package was never received (unless it was trackable) but is hard to explain why something was opened. I personally have worked with 2 guys fired for that exact reason, and they never took just a portion.