The Washington Post provides a lengthy report on the "FBI’s secret relationship with the military’s special operations." It reports that "the FBI’s transformation from a crime-fighting agency to a counterterrorism organization in the wake of the Sept. 11, 2001, attacks has been well documented. Less widely known has been the bureau’s role in secret operations against al-Qaeda and its affiliates in Iraq and Afghanistan, among other locations around the world."
"With the war in Afghanistan ending, FBI officials have become more willing to discuss a little-known alliance between the bureau and the Joint Special Operations Command (JSOC) that allowed agents to participate in hundreds of raids in Iraq and Afghanistan."
"The relationship benefited both sides. JSOC used the FBI’s expertise in exploiting digital media and other materials to locate insurgents and detect plots, including any against the United States. The bureau’s agents, in turn, could preserve evidence and maintain a chain of custody should any suspect be transferred to the United States for trial."