This question already has an answer here:
I don't have a source for this, but it is a well-known argument in the USA that:
black on white crime is huge, ergo black racists are a big problem
But, is black on white crime actually huge in the USA?
One way to judge whether its "huge" is of course, by comparisons. So, is black on white crime bigger than black on black crime in the USA? If not, then black on white crime might be explained not by racism, but simply by the fact that black people commit more crime on average, period.
Since there are more white people than black people in the USA, an appropiate answer should take that into account, using per capita units or something.