How can I remove an iPhone activation lock?

Apple can completely reset a device if a person can provide sufficient evidence of valid ownership. Do this online at: Activation Lock support request - https://al-support.apple.com/#/additional-support Apple says, "Proof of ownership documentation is required," but does not detail what currently constitutes proof. Prior to this new online service Apple typically required the original receipt issued by Apple or an Apple Authorized Reseller and documented provenance (so typically it would be the original owner who does this, or a descendant with legal proof of ownership). This will give you access to the device but won't restore access to the account used to lock it. There is nothing that can be done to expedite an Activation Lock request.

Apple recommends you "Keep your receipt after you buy an Apple device" --> Keep your receipt after you buy an Apple device - Apple Support

My personal observation is that even though you got it from the police, it does not demonstrate you are truly the owner according to Apple (the owner may still be the person who lost the device and is signed in on it) or that it was not in fact even stolen and something they recovered but couldn't find the common—but not Apple's definition of—owner. However, Apple will determine what they will accept.

I also do not know if they will still do this at an Apple Store, or since it has now been formalized, it only exists as an online service. An Apple Store may well just run it through the online request system. Back when it was done at stores the criteria were somewhat arbitrary and depended on the store's manager's opinion. It wasn't even a recognized procedure and a store could just say no, they didn't want to get involved. I get the impression Apple then decided to formalize and standardize the procedure and take it online.

None of that changes anything. You may be in possession of the iPhone, and even have paperwork to prove that you bought it at the police auction. It is entirely up to Apple if they want to unlock it for you. And you are not talking to Apple in these forums.

Hello ~ I can almost assure you Apple will not unlock that iPhone. It matters not where you purchased it. That iPhone was probably seized and unless the person/s who set the activation lock unlock it …it stays locked. Try if you would like and let us know how it goes for you.

~ Katana-San~

This is a strange case. I think you should just go to the Apple Store and see.