For decades conspiracy theorists have pointed to the US government’s refusal to release the John F Kennedy files as evidence of a cover-up around the former president’s assassination.

So Donald Trump’s assurance that “everything will be revealed” as he signed an executive order to declassify the trove of redacted documents will have set some high expectations.

But experts on the Nov 22 1963 assassination in Dallas, Texas, unanimously believe those hoping for a “smoking gun” to rewrite history will be bitterly disappointed.

The release, however, could provide some revelations to help shed light on topics, including how much the CIA really knew about shooter Lee Harvey Oswald ahead of the killing.