Racial biases lead to the arrest and incarceration of more Blacks, and typically for lower level offenses
(like drug possession instead of drug sales)
Despite the rates of drug use/drug offenses being relatively equal between Black and White groups, statistically, racial biases lead to the arrest and incarceration of more Blacks, and typically for lower level offenses (like drug possession instead of drug sales).
This is really already fairly known data, so I don't feel the need to expand on this. And while this article calls for penal reform, I think drug policy reform (decriminalization and legal regulation) would be better.