Fun With Scammers...

In most states they have a "Bad check law" and here it states the check writer pays double the amount of a bad check.
Accept the checks, then hire a private investigator to find them.
On a bad 14,000 check you could end up with 28,000 and/or a lien on everything they own.
It could end up being worth the trouble.

...........or just turn them over to the authorities...........