Ask for an NCIC check via local police or sheriff's office.
Edited to add: If the firearm is coming from someone who is a resident of a different state, the transaction must be intermediaried by a ND FFL holder assuming the receiving party is a ND resident.
Thanks for the advise, I intend to run the numbers prior to purchase. Negotiations seemed to have stalled as I wanted more on his end to make the trade square.