Law & Order: CI - Season Premiere question.

A friend of mine just got around to watching the season premiere of Law & Order CI, and has a question about one of the clues, but I didn’t really pay attention last week and can’t remember enough to help her. Can one of you astute souls please lend a hand?

Specifically, there was some revelation about a key chain, and that was the clue that triggered everything. So, what was it that Goren noticed about the keychain?

Thanks for any help,
thwartme