W. Mark Felt and Edward S. Miller
Edward S. Miller, not as notorious as Felt, was the head of the division of the FBI that ran the illegal searches of the homes of people suspected to be part of radical groups in the United States. He referred to these searches as “black-bag jobs.” He ran the jobs associated with the Weather Underground illegal searches.
Ford's Pardon of Nixon
A question remains whether the pardon was a quid pro quo; i.e. that Nixon agreed to make Ford president if Ford agreed to pardon tricky dick.