The United States Senate Hearings on the events at Abu Ghraib prison indicated an interesting lack of understanding between Major General Taguba and Undersecretary of Defense Cambone. Taguba said that when control of the prison was turned over to military intelligence officials, they had authority over the military police who were guarding prisoners. But Stephen Cambone, the Pentagon's undersecretary for intelligence, said that was incorrect, that authority for the handling of detainees had remained with the MPs.
Whos right? The answer is in the Fragmentary Order (FRAGO) issued by LTG Sanchez. It places the MPs under the tactical control (TACON) of the 205th Military Intelligence Brigade. The military has developed specific language to avoid such confusion. Terms such as TACON are clearly defined so that everyone in the field has a common base of understanding. Going to the source resolves this conflict.
FM 101-5-1 Operational Terms and Graphics defines Tactical Control as tactical control (TACON) (JP 1-02) - The detailed and, usually, local direction and control of movements or maneuvers necessary to accomplish missions or tasks assigned. (Army) - Tactical control allows commanders below combatant command level to apply force and direct the tactical use of logistics assets but does not provide authority to change organizational structure or direct administrative and logistical support. See FMs 1-111, 31-20, 71-100, 100-15, and 101-5.
The military individuals involved would understand that the 205th could issue orders to the MPs telling them what to do, with the limits of not changing the organizational structure. The Undersecretary of Defense should have understood that as well.