(Newser) – It's been 50 years since JFK was shot, but thousands of documents from the probe into his death are still off-limits to the public. Now an increasing number of serious researchers are seeking their release, reports the AP. "This is not about conspiracy, this is about transparency," says former Washington Post journalist Jefferson Morley, who has been fighting the CIA to see the documents for a decade. "After 50 years, there is no reason that I can think of why such operations should still be concealed," says the author of a book on JFK. "By withholding ... material, the agency continues to encourage the public to believe they're covering up something more sinister."

Among answers sought by the researchers include what ties Lee Harvey Oswald had to a pro-Castro activist group—was he a real member or part of a counterintelligence operation to discredit the group? And what is inside some 300 still-sealed pages on CIA agent George Joannides, who was involved in an anti-Castro group that clashed with Oswald's? The former chief counsel for the White House investigation into the assassination says he wasn't given the full background on Joannides, and neither was the 1964 commission that determined Oswald acted alone. "You have to wonder what is so important in a 50-year-old document," says Morley. "I've come to the conclusion that they're guarding something big, and that has stiffened my determination." (Read more JFK assassination stories.)

