The CIA holds documents that show presidential assassin Lee Harvey Oswald was involved in an intelligence operation before the assassination of John F. Kennedy, a prominent Kennedy assassination reporter alleged Tuesday.

“We’re talking about smoking-gun proof of a CIA operation involving Lee Harvey Oswald,” reporter Jefferson Morley said.

Morley claimed the CIA operation involving Oswald took place in the summer of 1963, three months before the assassination. The allegation from Morley, who has written extensively about the CIA in the 1960s, could shake up the history of the Kennedy assassination if it proves to be true. …

The claim from Morley, a former Washington Post reporter, came at a press conference for Kennedy assassination investigators that includes a sitting federal judge.