I could be mistaken but I thought is was Attorney General, John Mitchell, under President Nixon.
John N. Mitchell, Principal in Watergate, Dies at 75. John N Mitchell,
the only United States attorney general to serve a prison sentence,
died here yesterday after suffering a heart attack. He was 75.- Nov 10, 1988
I think you are right, and if Nixon had not been pardoned, he may have spent some time in jail.