It's not a PO Box, it's General Delivery (https://www.usps.com/manage/forward-mail.htm). There is no owner, but you may be able to get the info they recorded when the person showed up (undoubtedly fake).
Wouldn't doing something like that (providing fake ID at pickup) be considered Mail Fraud? I seem to recall mail fraud investigations having really big teeth.
IANAL (I've said that a lot in this thread), but I believe so. Actually, I think it may be mail fraud in any regard, if he's using the US Mail to take delivery of his booty and you can show that he had prior intent to commit this scam (which is why he didn't have the packages shipped to his home address). So, maybe the right place to start is with the Postal Inspector, especially since this guy seems like a repeat offender with the same MO.
