Assessments of the roughly 2,200 files posted by the U.S. National Archives and Records Administration on its website came with a huge caveat: No one had enough time as of Wednesday to review more than a small fraction of them. The vast majority of the National Archives’ more than 6 million pages of records, photographs, motion pictures, sound recordings and artifacts related to the assassination have previously been released.

An initial Associated Press review of more than 63,000 pages of records released this week shows that some were not directly related to the assassination but rather dealt with covert CIA operations, particularly in Cuba. And nothing in the first documents examined undercut the conclusion that Kennedy assassin Lee Harvey Oswald was the lone gunman in Dallas on Nov. 22, 1963.

“Nothing points to a second gunman,” said Philip Shenon, who wrote a 2013 book about the assassination. “I haven’t seen any big blockbusters that rewrite the essential history of the assassination, but it is very early.”

Kennedy was killed on a visit to Dallas, when his motorcade was finishing its parade route downtown and shots rang out from the Texas School Book Depository building. Police arrested the 24-year-old Oswald, a former Marine who had positioned himself from a sniper’s perch on the sixth floor. Two days later Jack Ruby, a nightclub owner, fatally shot Oswald during a jail transfer broadcast live on television.

Historians hope for new details about the man who killed JFK

A year after the assassination, the Warren Commission, established by President Lyndon B. Johnson to investigate, concluded that Oswald acted alone and there was no evidence of a conspiracy. But critics of the commission still spun a web of alternative theories.

Historians are hoping for details fleshing out Oswald’s activities before the assassination and what the CIA and FBI knew about him beforehand.

Shenon pointed Wednesday to previously released documents about a trip Oswald made to Mexico City at the end of September 1963. Records show Oswald intended to contact the Soviet Union’s embassy there after living as a U.S. defector in the U.S.S.R. from October 1959 until June 1962.

Shenon said the U.S. government may have kept information about what it knew about Oswald before the assassination secret to hide what he described as officials’ possible “incompetence and laziness.”

“The CIA had Oswald under pretty aggressive surveillance while he was there and this was just several weeks before the assassination,” Shenon said. “There’s reason to believe he talked openly about killing Kennedy in Mexico City and that people overheard him say that.”

Speculation about such details surrounding Kennedy’s assassination has been intense over the decades, generating countless conspiracy theories about multiple shooters and involvement by the Soviet Union, the mafia and the CIA. The new release fueled rampant online speculation and sent people scurrying to read the documents and share online what they might mean.

Many documents already were public but information had been redacted

The latest release of documents followed an order by President Donald Trump, though most of the records were made public previously with redactions. Before Tuesday, researchers had estimated that 3,000 to 3,500 files were still unreleased, either wholly or partially. Last month, the FBI said it had discovered about 2,400 new records related to the assassination.

Jefferson Morley, vice president of the Mary Ferrell Foundation, a repository for files related to the assassination, said in a statement posted on the social platform X that much of the “rampant overclassification of trivial information has been eliminated” from the documents.

The timing of the release drew criticism from a Kennedy grandson, Jack Schlossberg. In a post on X, Schlossberg said the Trump administration did not notify family members before the records were made public.

“a total surprise, and not shocker !!” Schlossberg wrote.

Trump issued his executive order to release the files on Jan. 23.

A boon to historians of the Cold War

The latest release also is a boon to historians of the Cold War. Timothy Naftali, an adjunct professor at Columbia University who is writing a book about JFK’s presidency, said scholars now appear to have more details about U.S. intelligence activities under Kennedy than under any other president.

For example, in October 1975, U.S. senators were investigating what the CIA knew about Oswald, and an October 1975 memo said they considered the agency “not forthcoming.”

A version of that memo released in 2023 redacted the name of the CIA’s security contact on Oswald in Mexico, as well as the identity of someone behind the “penetration of the Cuban embassy” there. The latest version shows that the security contact was the president of Mexico in 1975, Luis Echeverria Alvarez, who died in 2022, and that the Mexican government itself penetrated the Cuban embassy.

Also, Naftali said, before the latest release, the government had made public copies of Johnson’s presidential “daily checklist” of highly sensitive foreign intelligence in the days after Kennedy’s assassination, but with much of the material redacted. Now, he said, people can read what Johnson read.

“It’s quite remarkable to be able to walk through that secret world,” he said.

Some records provide small details about covert operations

Documents show that in December 1963, the CIA director’s office was receiving messages from and replying to operatives in Cuba seeking to undermine the government under Fidel Castro. One, on Dec. 9, 1963, relayed a message to the director from Cuba: “TODAY RECD THE MAGNUM PISTOLS BUT NO BULLETS.”

“You’re getting both a bird’s-eye view of U.S. foreign policy, and you’re also getting a snail’s eye view of covert action, right there on the ground,” Naftali said.

In a previously released April 1975 memo, the CIA downplayed what it knew about Oswald’s visit to Mexico City before the assassination. The memo said the CIA recorded three phone calls between Oswald and a guard at the Soviet embassy, but only in the last one did Oswald identify himself.

“We’re now discovering how much more the CIA and the FBI knew before the assassination about Oswald,” Shenon said. “And the question is, why didn’t they act on the information in their own files?”