text: _________________________________________________________________________________FM 2-22.3
  HUMINT collectors can use rooms within a building, tents, or other
  field-expedient methods to isolate the individual being screened.
  Screening a source within view or hearing of other potential sources
  may not only pose a danger to the source but also will tend to inhibit
  the source from freely cooperating.
  • Security. The personnel conducting the screening need to be able to
  concentrate on the individual being screened. Although the collector is
  ultimately responsible for his own personal security, screening is
  facilitated by having dedicated personnel present (for example, MPs)
  who are responsible for security. Screeners coordinate with MP or
  other security personnel concerning their role in the screening process.
  INITIAL DATA AND OBSERVATIONS
  6-30. Screening is a filtering process whereby, under ideal circumstances, all
  potential sources would be questioned to determine if they have information
  of intelligence interest. In actuality this is often impossible. Screeners often
  use visual and other aids to “prescreen” the sources in order to eliminate a
  substantial portion of the target population before conducting detailed
  screening. For example, if the HUMINT collector at a checkpoint is only
  interested in information concerning a specific denied geographic area,
  screeners may ask all refugees if they are from or have been in that denied
  area recently. A less experienced screener could do this allowing the
  experienced screener to conduct more extensive screening of the select target
  audience.
  6-31. If time and circumstances permit, screeners should question any
  friendly personnel who have had extensive contact with the persons to be
  screened. In the case of detainees, this could include holding area personnel
  or personnel from the capturing unit. These personnel may be able to help
  identify sources that might answer the collection requirements or who might
  match a particular source profile.
  6-32. Normally the screener will not have time to conduct any extended
  observation of the person to be screened; however, the screener should make
  a quick visual observation of the source prior to questioning him. He should
  note anything in the source’s appearance and behavior that indicates he is
  willing to cooperate immediately or is unlikely to cooperate. The screener
  should also note any physical indicators that the source may have the type of
  information or belong to a certain source profile category.
  6-33. Physical indicators include overall appearance such as rank, insignia,
  and condition of the uniform and type and condition of equipment for
  military sources and general type and condition of dress (for example,
  business suit as opposed to work clothes) for civilians. Certain physical
  indicators (dress, medals such as religious medals, physical type) may be
  indicators that the source belongs to a specific ethnic or religious group. The
  source’s physical reactions may also indicate a willingness or lack of
  willingness to cooperate. For example, does the source move forward in the
  group or attempt to hide within the group; does he intentionally place
  himself in the wrong segregation group; or does he show any overt signs of
  nervousness, anxiety, or fright?