In September 1971, his former
CIA superior,
E. Howard Hunt, recruited him for the "
Plumbers", the
Nixon White House's "Special Investigations Unit". He was recruited by Hunt to find background information on
Daniel Ellsberg. Ellsberg was under watch for leaking the "
Pentagon Papers", a series of articles featured in
The New York Times in 1971 detailing
U.S. government secrets concerning the
Vietnam War's history. Along with Hunt and
G. Gordon Liddy, Barker broke into the office of Ellsberg's psychiatrist, Dr. Lewis J. Fielding, in
Los Angeles. The mission's purpose was to find discrediting information on Ellsberg. The mission was completed, but largely unsuccessful in finding any damaging information about Ellsberg. In 1972, Barker was one of the five burglars paid by the
Committee to Re-elect the President (CRP), Nixon's re-election campaign fundraising committee, for a
break-in at the headquarters of the
Democratic National Committee, and subsequently was convicted in the
Watergate scandal. The others were
Frank Sturgis,
Virgilio Gonzalez,
Eugenio Martinez and
James McCord. Along with the other Watergate burglars,
G. Gordon Liddy, and
E. Howard Hunt, Barker was charged with, and
pleaded guilty to,
wiretapping, planting
electronic surveillance equipment, and
theft of documents. Hunt claimed that Barker gave testimony, corroborating his assertion to the
Senate Watergate Committee, that the reason they broke in was they were told by Liddy to search for evidence of clandestine financial contributions being received from foreign powers, such as Cuba. Barker also worked with CRP to get money which went into the Nixon campaign coffers off the books; it was via his bank account that $25,000 from
Archer Daniels Midland Chief Executive
Dwayne Andreas was obtained by CRP in violation of
campaign finance laws. On March 7, 1974, Barker, along with Ehrlichman,
Charles Colson, Liddy, Martinez, and Felipe de Diego, was indicted for the Ellsberg burglary. Barker was released pending appeal after serving one year of a two-and-a-half to six-year sentence. ==Later life and death==