What’s the actual case for CIA involvement in JFK’s killing?

It helps to separate the official findings. The Warren Commission concluded that Lee Harvey Oswald acted alone. In 1979, the House committee investigating the assassination said it was probably the result of a conspiracy, relying substantially on acoustic evidence. A later National Research Council review found that the acoustic evidence did not support the conclusion of a second gunman. The House committee did not identify another shooter or establish CIA involvement.

So there have been competing official conclusions about whether Oswald acted alone, but no public evidence that proves the CIA killed Kennedy.

The suspicion didn’t come from nowhere. The CIA ran covert operations against Cuba, including plots targeting Fidel Castro, and those efforts were not fully disclosed to the Warren Commission. That history gives people a reason to ask whether the agency had a motive or concealed relevant information.

But motive and secrecy are not a demonstrated connection to the assassination. Claims that Oswald was working for the CIA, or that the agency directed the killing, remain unproven.

For today, the clearest effect is on public trust. When intelligence agencies keep information secret, later gaps can make even ordinary uncertainty look like evidence of a cover-up. That is a reason to support oversight and timely disclosure, but it isn’t proof of a particular theory.

I’d keep the question narrow: what records support a specific claim, and what do they actually establish?