The FBI was warned that Lee Harvey Oswald, President John F. Kennedy's assassin, might be in danger of being killed himself just before Oswald was shot by Dallas nightclub owner Jack Ruby.

The revelations are part of a new trove of more than 2,800 records released Thursday evening from the National Archives pertaining to the 1963 assassination of President Kennedy.

In one document written on Nov. 24, 1963, just after Ruby shot and killed Oswald, then-FBI Director J. Edgar Hoover dictates in a memo that the FBI field office in Dallas had received a phone call from a man "saying he was a member of a committee organized to kill Oswald." The FBI notified the Dallas Police Department, which "assured us adequate protection would be given. However, this was not done," Hoover said. The memo also notes Ruby denies he made the phone call to the FBI.

Hoover goes on to call Oswald's killing "inexcusable" given the warnings they gave to Dallas Police about the threats they had received, and the FBI director also surmises that the president's shooter being shot so soon after his arrest would only sow doubt that Oswald was the real killer.

In the nearly 54 years since President Kennedy was assassinated, that's exactly what has happened, with questions continuing to arise about Oswald's motives, possible ties to Communist forces in Cuba and Russia and why Ruby, who had ties to the mob, would murder Oswald. And that's exactly why the release of these latest government documents is of so much interest.

As NPR's Brian Naylor reported:

The files are among the last to be released by the National Archives under a 1992 law that ordered the government to make public all remaining documents pertaining to the assassination. There has long been a trove of conspiracy theories surrounding Kennedy's death in Dallas on Nov. 22, 1963, including doubts about whether assassin Lee Harvey Oswald acted alone, as the Warren Commission determined in its report the following year.Other files are being withheld owing to what the White House says are national security, law enforcement and foreign policy concerns. The vast majority of what's being withheld is at the request of the FBI and the CIA.

Hoover also wrote that the FBI held out hope that Oswald would confess before he died, but that did not happen.

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