[drcy]

The science used in other areas of collecting and history is so sophisticated that, for example, it can tell you when an artifact was buried in the ground by measuring the atomic energy released since it was hidden from sunlight.

Yes, I think science could be used to conclusively identify all sorts of alterations, including trimming, in trading cards.

Whenever I'm asked to examine an item, I ask "Where'd you get it?" The answer may just be that they picked it up in a garage sale or found it in an attic, but I expect an answer. If it was bought in an auction, I always check out the auction listing.