Crucial JFK information still unreleased: Author James H. Johnston
His comments come after the remaining classified files on the assassination of Kennedy were released Tuesday.
A missing memorandum documenting a conversation between former President Lyndon B. Johnson and ex-CIA Director John McCone days after President Kennedy's assassination could contain crucial information that was never submitted to the National Archives, according to an author.
James H. Johnston, author of "Murder, Inc., the CIA under John F. Kennedy," told NewsNation that the memorandum was written following a private hourlong conversation between Johnson and McCone at the author's residence six days after the former president's death.
His comments come following the release of the remaining classified files on the assassination of Kennedy were released Tuesday on the National Archives website.
"John McCone always wrote a memorandum for the record of any conversation he had with the president," Johnston said Wednesday on NewsNation's "Elizabeth Vargas Reports."
"And that memorandum was not given over to the National Archives and is not available," he added.
JFK memo reportedly discussed Cuba and Castro after assassination
According to Johnston, State Department historians viewed the document in 1997 and noted the conversation included discussion about Cuba and "how they were going to get rid of [Fidel] Castro." The full contents of this conversation remain unknown to the public.
President John F. Kennedy gestures with open hand during dedication ceremonies at the Nashville Avenue Wharf in New Orleans, May 4, 1962. (AP Photo/BS) 
The limousine carrying mortally wounded President John F. Kennedy races toward the hospital seconds after he was shot, Nov. 22, 1963, in Dallas. (AP Photo/Justin Newman, File) 
American President John F. Kennedy talks with American television news producer Fred Friendly in the White House during the filming a televised interview entitled 'After Two Years: A Conversation with the President,' in Washington D.C., on Dec. 16, 1962. (Photo by CBS Photo Archive/Getty Images) 
An undated image released by RR Auction shows home film footage of President John F. Kennedy's motorcade speeding down a Dallas freeway to the hospital after he was fatally wounded on Nov. 22, 1963. (RR Auction via AP, File)
Gerald Posner, investigative journalist and author of "Case Closed, Lee Harvey Oswald and the Assassination of JFK," acknowledged the document might exist but questioned its relevance to understanding the assassination.
"If there was a large conspiracy to kill the president, the evidence of it is not going to be found in the release of files from the National Archives," Posner said, suggesting any truly incriminating documents would have been retained or destroyed rather than archived.
Both authors discussed killer Lee Harvey Oswald's visit to Mexico City six weeks before the assassination, where he visited Soviet and Cuban embassies. Posner questioned why the CIA, which had monitored Oswald since his 1959 defection to the Soviet Union, didn't alert the FBI about his concerning behavior following this trip.
Johnston also explained that during this Mexico City visit, Oswald reportedly met with a KGB operative known for assassination operations, though he didn't suggest this directly connected Oswald to Kennedy's assassination.
NewsNation’s Ross Coulthart will host a special report, “Declassified: The JFK Assassination,” this Saturday at 8p/7C. Find out how to watch at NewsNationNow.com.
