What cops and courts believe doesn't mean a darn thing if a single juror can be caused to doubt it. I was personally burglarized once, and the ONLY reason I got my camera gear back is that I recorded specific serial numbers, which matched those on the suspected stolen items. For the same reason, I told my customers to record their serial numbers on their receipts, and carefully file those away, or else they could never prove specific theft, or have full leverage with the insurance company itself. We once did that for them, but over the long haul, due to the sheer volume of sales, it became unrealistic for us to keep doing ourselves. Or take a xerox copy of that to a suspect outdoor trade fair, and if you see what your think is yours there, snag the attendant pollice officer, and he'll reclaim it and arrest the seller on the spot.
Storefront fences - retailers specializing in stolen goods, require a lot more caution and plainclothes officer attention. They've got guns and buddies with guns keeping an eye on people. Those busts take time, but involve serious prison sentences, typically around 12 to even 20 yrs in the instances I was involved with, since it was often our own diverted shipments which brought attention to the felons. A few times, entire warehouses of stolen equipment were identified, predictably in LA. Nowadays, some of the smash and grab operations even have the gall to have their own websites and online sales function. One of those was busted a few weeks ago with over 18 million in stolen goods in it. You buy something like that, you lose your money, and still have to give back the item you paid for, if it was stolen. And an online purchase makes that easy to trace. Too good a deal to be true? - it probably is.