The girlfriend purchased the lower receiver. As far as the ATF knew, this was a legal purchase.
Then Frank Perry purchased items online to finish the firearm. All those items were legal for Frank to purchase. He had them sent to his girlfriend's house.
It appears, though we do not know for certain, that data mining linked Frank's name to the Boogaloo movement, then linked to his conviction in 2012, then linked to his purchase of firearm related items and parts, sent to his girlfriend's house.
Finally, it appears they linked the purchase of the lower receiver, by the girlfriend, in order to make the case.
Where did they obtain probable cause to have a search warrant issued?
My best guess is they went to the girlfriend and broke her, (pretty easy) and used her testimony to get the warrant.
It would be very useful to know how they got the warrant.
and now the boating
Accidents are
“Walk the Planck.”