They pretty much had to search the books for something to charge him with:
> 3rd degree criminal possession of a weapon... which sounds to me like an invented charge for the unassembled AR-10/AR-15 parts.
> 1st degree reckless endangerment, which is effectively a trumped up charge for feeling “disturbed.”
You can have every AR part but one, and not have a firearm, assembled or unassembled. The fact that they refer to “parts” not “guns” suggests there were no lower receivers involved, just a bunch of parts that anyone can legally buy and own.