That’s a reason I don’t generally think we have secret alien tech. Too many people. Too many loose lips.
In the JFK case, you could have kept it to under a handful of people who actually were aware.
Again, I don’t necessarily think a “hit” came from the head of the CIA on the president.
I don’t think it’s unreasonable that individuals in the CIA made contact and in some fashion “encouraged” or “aided” LHO in his desire to kill JFK.
Once again, if there was nothing to be hidden, things wouldn’t be hidden.