Police ride along goes wrong for female passenger.

[saddler]

"Officer’s searched the area and located an AR15 style pistol and other evidence. "

What's one of those then?

As above (but I haven't engaged smug mode ), for some bizarre reason in the US if you remove the stock from a rifle that makes it a pistol under their legislation...

NOPE

Under US laws, if you remove the stock from a rifle that makes it an illegal rifle!

"Rifle" based pistols MUST start life as a plain brand new/unused receiver, that has NEVER had a shoulder stock fitted (& ideally has no provision for a stock) That way, as you are now instead, assembling "a pistol" it can be fitted with a pistol (sub-16") barrel.
It's also an offence to add a stock to a pistol in the US -though pay the $200 tax/BATF paperwork & it can be then fitted with a stock as a sub-16" carbine.

Similar options apply for shotguns.
Cut down a "shotgun" to sub 18" barrel = $200 tax stamp & BATF needed.
Use a virgin shotgun receiver (never been assembled as a gun or had a stock on it) = $5 A.O.W. tax stamp!! - then add a grip & a 12"-14" barrel