It was G.H.W. Bush (Bush Sr) and there photographic evidence proving he was there, despite his insistence that he wasn't. He was ALWAYS deeply involved with the CIA and later became head of it. That's a pretty good indicator that the murder of JFK was a CIA operation.
The Bushes have some loose connections to the assassination attempt on Regan as well.
If Bushes are involved, it makes sense that, even though the JFK files are supposed to be released now, it’s not happening.