Turkey, propaganda and eyewitness media: A case study in verification for news by Sam Dubberley.
I would amend Michael Garibaldi‘s line in Babylon 5: Exercise of Vital Powers (#4.16):
Everybody lies.
to read:
Everybody lies. [The question is why?]
No report (“true” or “false”) is made to you without motivation. The attempt to discern that motivation can improve your handling of such reports.
Sam’s account is a great illustration of taking the motivation for a report into account.