The FSA Detention Facility was a jail facility located in San Francisco, California on Earth. The facility was operated by the Federation Security Agency.
The facility had a color scheme similar to that of Galaxy-class vessels in the 2360s. It was primarily used to hold individuals arrested by the FSA prior to trial, which included both Starfleet and civilian personnel.
Following the exposure of Section 31 to the public, a number of its agents were arrested by FSA agents and after being returned to Earth were held at this facility. Among the high value detainees being held at the facility was Admiral William Ross. One of the people assigned to guard him was Margo Dempsey, who killed Ross and his attorney in retaliation for the death of her husband Clark at the hands of Section 31.
After Ross's death, the FSA and Starfleet reevaluated procedures, with access to Section 31 detainees being limited to those approved by Federation Attorney General Phillipa Louvois or Fleet Admiral Leonard James Akaar. (TNG novel: Available Light)