text: _________________________________________________________________________________FM 2-22.3
  problems with the use of the "we know all" approach. The HUMINT collector
  is required to prepare everything in detail, which is time consuming. He
  must commit much of the information to memory, as working from notes may
  show the limits of the information actually known. It is also only usable
  when sufficient prior information exists to convince the source that “we know
  all.”
  8-55. File and Dossier. (Interrogation) The file and dossier approach is a
  variation of the “we know all” approach. The HUMINT collector prepares a
  dossier containing all available information concerning the source or his
  organization. The information is carefully arranged within a file to give the
  illusion that it contains more data than actually there. The file may be
  padded with extra paper if necessary. Index tabs with titles such as
  education, employment, criminal record, military service, and others are
  particularly effective. It is also effective if the HUMINT collector is reviewing
  the dossier when the source enters the room and the source is able to read his
  name on the dossier and sees the numerous topics and supposed extent of the
  files.
  8-56. The HUMINT collector proceeds as in the “we know all” approach. He
  refers to the particular labeled segment of the dossier before, during, or after
  asking a question. In the early stages of questioning, the HUMINT collector
  asks questions to which he has the answer. He may answer along with the
  source, complete the information for the source, or even show the source
  where the information is entered in the dossier. He never lets the source
  physically handle the dossier. As the source becomes convinced that all the
  information that he knows is contained within the dossier, the HUMINT
  collector proceeds to topics on which he has no or little information. In doing
  so, he still refers to the appropriate section of the dossier and may even nod
  his head knowingly or tell the source that the information the source is
  providing still matches what is in the dossier.
  8-57. This technique has several limitations and drawbacks. The preparation
  time in developing the dossier is extensive. The success of this technique is
  largely dependent on the naiveté of the source, volume of data on the subject,
  and skill of the HUMINT collector in convincing the source that the dossier is
  more complete than it actually is. There is also the risk that a less naïve
  source will refuse to cooperate, claiming that, if the collector already knows
  everything, there is no need for him to talk. Also with this technique, the
  HUMINT collector is limited in the method he may use to record new
  information. If the HUMINT collector writes down information, it destroys
  the illusion that all the information has already been obtained. The
  HUMINT collector is normally limited to using electronic recording devices or
  his memory. The HUMINT collector can also arrange ahead of time for
  another interrogator or analyst to take notes for him, undetected by the
  source. This could be especially effective in a situation where a separate
  monitoring area (for oversight) is used by the analyst.
  8-58. Establish Your Identity. (Interrogation) In using this approach, the
  HUMINT collector insists the detained source has been correctly identified as
  an infamous individual wanted by higher authorities on serious charges, and
  he is not the person he purports to be. In an effort to clear himself of this