How to verify if an iPhone is stolen using Serial number?

There is no way to check on the status of a phone with the serial number.

If you are thinking of buying the phone, don't even touch it unless it displays the "hello" screen.

To add what Bob Timmons said, you won't always be able to rely on the seller providing you the correct information. They can easily just send you the same picture that you see here. Also review these other situations that may apply:

The All Too Common SAD Reality of Buying … - Apple Community

Another common scam going around involves a person selling their phone, then filling a theft claim where they will get a new device and their old one will then no longer be functional.