The first public revelations of the program came in a video conference aired in October by To the Stars Academy for Arts and Sciences, the firm Elizondo joined as a consultant after retiring from his Pentagon job. The New York Times and Politico reported the existence of the program on their websites Saturday. The Washington Post conducted several confidential interviews over two months with Elizondo and Christopher Mellon, a former deputy assistant secretary of defense for intelligence who also is an officer of the private firm.