Two other comments:
Here is a DC conspiracy where _nobody_ talked _ever_. Thousands of people knew the secret and _nobody_ talked! It was only discovered by a professor doing obscure research at the Commerce Department after all the participants in the plot were dead:
https://www.scientificamerican.com/article/confirmed-the-us-census-b/
We do have a deathbed confession of one of the CIA conspirators in the JFK assassination—I would strongly encourage you to read it:
https://www.amazon.com/Bond-Secrecy-Watergate-Conspirator-Howard/dp/1936296837
No one has ever proved any concrete proof of a plot to kill JFK but dozens of people have made a lot of money picking at his corpse.