I, like everyone, else likes to buy in cell phones from people who come in to my store and just wants to get rid of their phone. 99% are honest and don't attempt to sell you stolen goods.

However, that 1% sure can be costly. I had the police in my shop today that said two phones were reported stolen I had in my display case. I did some more investigating and sure enough the dirtbag sold me phones he stole. I lost the phones and $75.

Now, for the question... What do you all do to prevent this from happening? This is the first time it has happened to me in three years of doing this so, it isn't a terrible problem. But since it did happen, I want to prevent it from happening again.