Next month marks the 40th anniversary of the assassination of John F. Kennedy, an event surrounded by mystery and conspiracy theories.

Just in time for the milestone, a retired US Air Force sergeant is coming forward with new information he claims proves the CIA was involved in the Kennedy shooting.

Robert Vinson says the day of the assassination, he was trying to hop an Air Force flight from Washington D.C. to Denver, but instead ended up on an unmarked government plane which stopped in Dallas and picked up two men -- one of whom looked just like Lee Harvey Oswald.

Vinson says no one spoke to him during the flight, which terminated in Roswell, N.M. at a secret CIA base.

He admits he doesn't understand everything that happened that day, but he's sure the mysterious flight had something to do with Kennedy's killing...