I recently sent a 19 pound package to Jacksonville. It arrived resealed, no notice of opening it, and light 18 pounds! USPS went shopping in it. It was filled with childhood memories for my daughter. They did nothing. They laughed at her and said it happens all the time. They refused to reimburse for the missing weight I paid for. They called the issue resolved and closed the case. The cops were called and a report filed. They said they could do nothing without more complaints.
File criminal reports people.
All the temp workers probably treat it as a shopping trip.