At any rate they didn't just say the information exists, they also said it was basic pawn shop training, so I googled "pawn shop detect stolen goods" the top answer was from quora https://www.quora.com/How-do-pawnbrokers-verify-that-the-ite... and there was something from a blog of somebody called the blog nerd which is a little difficult reading because of all the SEO keyword optimization he seems to have done

https://www.pawnnerd.com/how-do-pawn-shops-track-stolen-item...

there seemed to be a reasonable number of other informative links.