E. Howard Hunt

Prior to working for President Richard Nixon as part of the White House "plumbers" unit--organized to track down the source of leaks of documents that the White House did not want to become known--Watergate operative E. Howard Hunt worked for the CIA. He conducted break-ins at the Watergate complex at Nixon's orders in the name of "national security" (supposedly they were looking for evidence that Cuban leader Fidel Castro was secretly contributing funds to the Democratic party). After the scandal broke and the investigations of the incident were complete, Hunt was imprisoned for his illegal activities in the operation.

Biography from TMDB.