Lost and Found iPhone "Locked to Owner".

No, it cannot be unlocked. Activation lock is a security feature and only the owner of the Apple ID and phone can remove it. This phone is useless to you, turn it into the authorities.

The phone may have been in a bin behind a store because it was stolen, and the thief or fence found out that it was an Activation Locked brick.

From what you are saying, you do not have proof of original purchase from Apple or an Apple Authorized reseller that might be sufficient to convince Apple to clear Activation Lock. If you keep the phone, Activation Lock will stay in place and the phone will remain a “brick.”

That link is useless for them because they are not the owner and would not have proof of ownership that Apple requires.

Depending on how old the phone is and if it's set to "lost" by the owner, you could try this:

https://al-support.apple.com/#/additional-support