Heather MacDonald has this great article in the City Journal, persuasively debunking the myth that high black incarceration rates result from racial discrimination. She reviews the available empirical evidence, which finds no evidence of systemic racism. Instead, the studies show that a disproportionate number of African-Americans are in prison because they have committed a disproportionate number of serious crimes.
It is a tragedy that so many minorities are languishing in prison. But the "solution" that the Left often proposes of targeting racist cops or racist prosecutors is, as MacDonald demonstrates, wide of the mark. Instead, we need to look at the causes of higher rates of minority offending.