fact is, blacks have NEVER had anything approaching a fair shake in the criminal justice realm. particularly not in the south; I don't even think we need to discuss pre-1965. since then it's a more complicated realm of oppression that has taken over via a synthesis of drug laws, several moves by the Supreme Court to weaken the power of the 4th Amendment, racially disparate on-the-ground policing tactics (a very small part of which is explained by the concentration of blacks in urban ghettos, to be fair), the high cost of access to legal services, and the
"Trial Tax" that effectively forces even those who believe themselves to be innocent to plead guilty/no contest. it's no coincidence that incarceration rates have skyrocketed since the implementation of civil rights law and the end of lynching as a tactic of state terrorism.
as a result there's a constant tinder of black resentment, anger, whatever you want to call it and a white cop pouring bullets into a black teen provides the propane.