text: _________________________________________________________________________________FM 2-22.3
  HUMINT collector will need to arrange for security from the unit that has
  established the holding area.
  5-64. If the MP departs the immediate area where the detainee is being
  questioned (for example, asked to wait outside the interrogation room), the
  HUMINT collector will assume custody and responsibility for the detainee by
  signing for the detainee, noting the detainee’s physical condition.
  5-65. SOPs should be written to comply with a requirement that
  interrogation operations will always be under observation, whether
  conducted in fixed sites, holding areas, or in the field. Physical setup and
  logistical availability will dictate whether observation is conducted directly,
  from a concealed location, or by video monitoring. HUMINT collectors should
  never be alone with a detainee without being under observation.
  5-66. Once a HUMINT collector has assumed custody of a detainee, he will
  not turn the detainee over to anyone other than an MP. Specifically, he will
  not allow another government agency to assume custody from him. The
  HUMINT collector will instead return the detainee to the custody of the MP,
  and the agency seeking custody of the detainee will then be required to do so
  from the MP. Likewise, HUMINT collectors will not assume custody of a
  detainee directly from another government agency, but will require them to
  return the detainee directly to the custody of the MP.
  LEGAL, REGULATORY, AND POLICY PRINCIPLES AND GUIDELINES
  5-67. The GPW (Appendix A, Section I), the GC (Appendix A, Section III),
  and the UCMJ are relevant documents pertaining to interrogations of
  detainees.
  5-68. The approaches, psychological techniques, and other principles
  presented in this manual must be conducted in accordance with applicable
  law and policy. Applicable law and policy include US law; the law of war;
  relevant international law; relevant directives including DOD Directive
  3115.09, “DOD Intelligence Interrogations, Detainee Debriefings, and
  Tactical Questioning”; DOD Directive 2310.1E, “The Department of Defense
  Detainee Program”; DOD instructions; and military execute orders including
  FRAGOs. US policy is to treat all detainees and conduct all interrogations,
  wherever they may occur, in a manner consistent with this commitment.
  Authority for conducting interrogations of personnel detained by military
  forces rests primarily upon the traditional concept that the commander may
  use all available resources and lawful means to accomplish the mission and
  to protect and secure the unit.