Why would they require a background check for your property?
Next they will ask for a psych exam.
Look, they obviously don’t want to give the gun back.
Cops do whatever they want, to whomever they want every day.
I can look up and find hundreds and hundreds of links and articles that support that statement. Cops can say and do whatever they want.
I’m telling you what to do, and you’re getting all defensive about it. Get a lawyer, contact your state reps, contact the NRA, contact the DA. Continue going into the station/courthouse every day and telling them you want your gun back.
They are already giving you a hard time, when they should have returned your property. You’re dealing with the POLICE who get away with murder on an almost daily basis. If you really want your gun back then you’re going to have to put some time and effort into it, since they haven’t given it back already.