Ferguson, St. Louis County, pop. about 21,000, is about 70% Black (2010; but in 1990, 74% white).
Whites moved or are moving out, but a white-guided governing structure remains, creating a problem city.
The police force has Black officers, but I don't know the percentage in the force, and the top seems to be White.

In 2013, 86% of vehicle stops were of Black people, and 93% of arrests.