Then you’re fucking comically unlucky, there’s a shooting and some old enemy offs someone at the same address and flee, minutes before the police gets there.
Some pissed off riff-raff family member decides that you look like the killer.
You’d better have a top notch lawyer in your family or prepare to spend lots of money hiring one.
If you're really concerned about that you could go to a local bar and call from there. Make sure you have the attention of the bartender while making the call. Easy alibi, the bartender won't forget something like that
I think the idea isn't to really bring a firearm into the situation, it is just to tell the cops that you are considering doing so.
Which, in your hypothetical "you might get extremely unlucky" scenario, should give you no problem, since you never had a firearm on you in the first place.