The files in question, some released under direction of the court and hundreds more that are still secret, involve the curious career of George E. Joannides, the case officer who oversaw the dissident Cubans in 1963. In 1978, the agency made Mr. Joannides the liaison to the House Select Committee on Assassinations — but never told the committee of his earlier role.
In other words, the CIA planted a man with a good reason to keep the secrets of the JFK assassination on the very committee tasked with re-examining the JFK assassination.
BTW I notice that History(?) Channel is pounding away at shows reinforcing (re-selling) the official version of the JFK assassination. It's a refreshing break from the Nostradamus and Nazi fare, but still not worth wasting bandwidth on.