They seized the 4473 forms every gun buyer fills out when they purchase a gun at a licensed dealer.
Probably going to check if the info on the forms is accurate and truthful. You know, like they’ve done with the 4473 Hunter Biden filled out by hand, and signed, where he stated he wasn’t a user of illegal drugs.
Despite all the contemporaneous selfies of Hunter smoking crack/meth, should be added to that for completeness.
The evidence is out there.