If the gun is important to you document why.
Get records of sale with serial numbers if possible.
Get records of all needed gun permits, for all those in possession of the gun you the safe owner and girl.
Get written letters of agreement for storage and handling from same.
Get written permission from those parties for the return of said gun, and written expressions that nobody is expected to suffer in any way from said gun's return to you. In other words, limit the liability of said police department in returning said gun to you. Do not leave them wondering why you were not handed the gun yourself. Explain this, fully.
If you cannot adequately explain why a dangerous firearm was not left with you, but rather them, you will likely never see said lethal weapon again. The liability is simply too great for them to responsibly ignore.
And then appeal to the officer in charge of that situation in person at a slow time in his day. He will not want to be trusting of you; his liability is high.
Should he give you a gun and anything happen to that gun with that gun or because of that gun his career might well be toast.
Tell him of any other guns you may have especially those of near similar charactoristics to the estranged gun. In other words show there is no increase in liability to the citizenry should the gun be returned.
If the gun still is not returned ask for a reason, in writing.
If the reason is that they told the girl it would be seen as a gift to the police department then I would actually consider three options: 1.) your house insurance, if his does not like your suit or goes after the girl (after all she seems to have been your friend even if you cannot see this, now, as she did try to make arrangements to protect your interests) 2.) small claims court (again against the police department) unless the gun is too very valuable and in that case why no insurance on this gun? 3.) a higher authority in the policing of firearms. It might well be that the firearm was not properly and legally transfered in ownership.
Even a gift does indeed need some doccumentation in some instances.
Actually ask to speak to the police department's supervising authority or it's retained attorney, in writing before civil case is innitiated.
In some cases there is no protocal for the handling of such cases in some police departments. After all, they are not a storage locker for private property.
I can see that your friend did indeed protect your interests in some respects. Nobody can fault you in a death from said lethal weapon, for instance. That is why you left the gun with her in the first place.
Evidently for what she did there was reason in her mind (and you yourself chose this mind to be the mind responsible for your property ~ a lethal weapon ~ I see no reason to fault your choice, you present no evidence she made a bad choice given her circumstances then).
Of course she did not satisfy your every whim. But your every whim is not the issue here, the greater good is. and even for you leaving your gun with the police offers you no increase in liability.
Liability in matters concerning lethal weapons can be in the millions.
Loss of a few dollars replacement cost is literally nothing compared to that.
You offer no evidence of a monetary arrangement to compensate her in any way for her increased risk in storing your arm, thus demonstrate no refered financial ability to provide for other arrangements that might have satisfied your own implied need to differ liability.
You yourself set by implication the minimum requirements for storage. You cannot then expect her to lower those requirements. Nor if you have not provided for contengencies can you expect her to do so. Gun clubs do background checks before issueing lockers even when they do issue lockers. She might not have been able to wait. And the locker at the bus depot or YMCA simply is not as safe as your implied requirement for reduction of your liability.
You knew situations can change, that is why you wanted your gun in a gun locker rather than a locker at the YMCA. Because you knew a gun left out on the street might get used to kill someone, you got secure storage.
She lost the ability for some reason to assure secure storage. I think you know that.
I think if YOUR insurance company is reasonable they will see you acted in their best interests, and give you your due ~ providing you: 1.) listed this gun as an asset if required by your home insurance 2.) did not get a decrease in your insurance based on the presence of said gun in your home, proper. After all, your acrtions decreased rather than increased thier liability.
And if they are worth thier salt they will not try and lay off this expense on the girl, who also acted in thier best interests, as well as yours.
His insurance company is not as liable as they 1.) might not know he had the gun and thus not have charged him for it 2.) might see this