Alexander Butterfield reveals the existence of the Nixon tapes:
When Nixon was re-elected, Butterfield was appointed on December 19, 1972 as administrator of the Federal Aviation Administration. He was routinely asked to appear before the United States Senate committee headed by Sam Ervin and was interviewed by staff of the committee on July 13, 1973, prior to going before the Senators. John Dean had previously mentioned that he suspected White House conversations were taped, and the committee was therefore routinely asking witnesses about it. Butterfield did not want to voluntarily tell the committee of the system, but had decided before the hearing that he would, if asked a direct question.
As it happened, Butterfield was asked the direct question by the minority (Republican) counsel, Donald Sanders. He told the staff members that "everything was taped ... as long as the President was in attendance. There was not so much as a hint that something should not be taped." All present recognized the significance of this disclosure, and Butterfield was hastily put before the full Committee on July 16 to put the taping system on the record. Chief Minority Counsel, Fred Thompson, catapulted himself into history by asking "Mr. Butterfield, are you aware of the installation of any listening devices in the Oval Office of the president?"