DCist has this follow up story on the year long quest of a DC ANC commissioner to get information about crime prosecutions in the city. The DOJ insisted that it didn't have the information, but released similar information to Congress. After it finally handled over the information, the DOJ and the requester settled the litigation brought by the requester.
DOJ still insists that it wasn't a FOIA request that brought about the release because they claimed to not have the information in the specific way the requester sought it - the requester sought it by Ward, the DOJ had it by Police District and the two are not the same.
This case illustrates a fundamental problem in FOIA and agency unwillingness to deviate from black and white rules - even though some courts have already done so - If the records are not exactly how the agency has them maintained they will argue they have no responsive records rather than offer what they have or make changes to lists to produce them how they are requested. Because DOJ will defend these types of bureaucratic stubbornness rather than make agencies reach compromises in the spirit of openness, requesters will continue to have difficulty in getting information compiled in databases for the foreseeable future.