happened. >> there was a surprise witness at the watergate hearings today, and he made a dramatic disclosure. >> we didn't know who he was or why he was coming. we never heard of him. >> and so the mystery guest turns out to be alexander p. butterfield. he has been described as one of the half dozen people at the white house closest to the oval office. >> will you stand and raise your right hand? >> i knew -- i knew it was just going to be huge. >> mr. butterfield, are you aware of the installation of any listening devices in the office of the president? >> i wasn't sure what would happen to me, but one thing i did know is i had always been honest. >> i was aware of listening devices, yes, sir. >> did he say there were tapes? what? >> yeah, talk about a bombshell.