Ferguson city leaders say they haven't heard from the U.S. Department of Justice regarding two federal investigations, one into the fatal shooting death of Michael Brown in August and the other into the city police department's practices.

Earlier this week, Attorney General Eric Holder said he expects the Justice Department to announce the results of those investigations before he leaves office. His successor will likely be confirmed within weeks.

Ferguson City Attorney Stephanie Karr and Mayor James Knowles III said Thursday they haven't been contacted by the Department of Justice about any findings, nor given a timeline for completion of the investigations.

The shooting raised concerns about the racial makeup of the mostly white police department and its relationship with the suburban St. Louis community, which is about two-thirds black.