A method and system of security screening of packages before packages are shipped by a commercial shipper. The method and system compares the configuration of the contents of the package when it is packed to the configuration of the contents of the package just prior to placement of the package on a commercial carrier. A first image of the configuration of the contents of the package is created when the package is packed. A second image of the configuration of the contents of the package is created by scanning the package at the shipping station. The images are compared to determine whether the images are the same within preset parameters. The package is segregated if the image differs beyond a preset amount.