I agree completely with this. I've gotten the long beep at the metal detector a handful of times (no pun intended). I suppose I could see how someone unfamiliar with these sorts of processes could think they were fingerprinted when in fact their hands/fingers were swabbed.

I have also been fingerprinted for government security clearance and you KNOW when you've been fingerprinted. It may be easier to explain to your father how the hand swab typically is performed (ie, wipe a piece of paper over your hand and fingers) and looking for the deviations, rather than asking exactly what happened.