The displayed number is an observation
Caller ID information can be manipulated. A displayed number may belong to a real person or business that had nothing to do with the contact, or it may be deliberately chosen to resemble a local or familiar number.
Callback numbers can be different
A voicemail or live caller may tell you to call a number that is different from the number displayed by caller ID. Record both. They are separate observations and may play different roles in later research.
What STIR/SHAKEN does — and does not do
STIR/SHAKEN is a caller-ID authentication framework used by voice service providers. It helps providers authenticate and verify caller-ID information carried with many IP-based calls and is one tool used to combat illegal spoofing.
It is not, by itself, a determination that the person or business associated with a call is legally responsible for a marketing campaign. It is also not simply a call-blocking system.
Network participation is not campaign control
A carrier or intermediate provider appearing in a call path can be technically important without being the advertiser, seller, call-center operator, or party directing the campaign. Those roles should not be collapsed without supporting records.
Official FCC material
Consumer complaint guidance covering unwanted contacts and spoofing.
FCC consumer guidanceFCC materials describe STIR/SHAKEN as a framework for authenticating and verifying caller-ID information.
FCC call authentication