Who is Deep Throat ?

After working as an investigative reporter for 36 years William Gaines retired to teach jouranlism at University of Illinois at Urbana-Champaign. One of the assignments he gave his students was to find the identity of Deep Throat of Watergate fame.
Many attempts had been made before to find the identity of this person. Bob Woodward and Carl Bernstein have said that they will not reveal the identity of this person till his death. So it has been all speculation so far.
The strategy taken by Gaines’ students was to search information to find out who all were present in Washington during the time Deep Throat met the jouranlists. Also from analysing the information, they concluded that only a member of FBI or White House would have access to the information which was revealed.
Finally, they narrowed it down to one person. Fred Fielding, an attorney and assistant to White House chief legal counsel John Dean.
bq. As far as we could determine, Fielding shared Deep Throat?s taste for cigarettes and whisky. He had access to information that Deep Throat corroborated for Woodward and Bernstein. And as student Robert Breslin found in 2002, Fielding even fit a characterization of the mysterious source that Woodward and Bernstein deleted from that early, unpublished draft of their book. The reporters wrote that Deep Throat was “perhaps the only person in government in a position to possibly understand the whole scheme and not be a potential conspirator himself.”
[via “Smithsonian”:http://www.smithsonianmag.si.edu/smithsonian/issues03/dec03/presence.html]