Hopefully the owner will try and track it and or ring it @therivetman
I assume it's password protected.
If it says No Service in the top status bar then the owner has had the phone blacklisted and its imei blocked.
You could hand it into a place near where you found it as the owner may check in to see if the phone has been handed in or into a lost property desk at a police station.
Unfortunately Samsung themselves I doubt would be able to help due to privacy laws etc.
That said well done you for being honest and having integrity.