[RS]

If these people presented NO acceptable ID, they could have been presented with the option of giving fingerprints and photos to be checked BEFORE entry, or to simply turn around and go back.

Through checking of their ID does NOT entail taking photos and fingerprints AFTER they have proved their right to entry, no matter where they have been.

[FreeReign]

If these people presented NO acceptable ID, they could have been presented with the option of giving fingerprints and photos to be checked BEFORE entry, or to simply turn around and go back.

Various ID's can be forged. Apparently, fingerprints are the accepted ID.