What's the meaning of the phrase 'Black-on-black'?
Interactions that occur between black people, notably crime that is perpetrated by one black person against another.
What's the origin of the phrase 'Black-on-black'?
This term originated during the race riots in the USA in the late 1960s. The earliest record I can find of it in print is this piece from The Chicago Daily Defender, March 1968:
"The violence of black man stabbing black man, mugging black man stomping black man, raping black woman. Black on black. And a black crime against a black gets cancelled out in the mind of a white precinct commander."