We found a lost/stolen restored iPhone 5S on our front porch?

My father and I found a random black iPhone 5S in a black OtterBox case on our porch. When he turned it on it was going through the setup process where you setup the password, login, etc, etc. (I'm guessing someone restored it) We went through the phone to see if there was any phone numbers on it we but we couldn't find anything.
The only thing we know is the phone's phone number and the carrier (Verizon)
I was wondering what we should do this situation. Who should we call? What can we do to make sure this phone is returned to the rightful owner?

Turn it in to the police department. That's where you normally turn in found property if you don't know who the owner is.

Turn it in to the police.