This is due to over-incarceration when police officers see people as threats. This is also due to the war on drugs.
states with the highest rates are Louisiana, Delaware, Mississippi whereas states with the lowest rates are Maine and Massachusetts.
Robbery, which might be considered a more common factor, is only 3.4% of all incarcerations
One of the key contributing factors is drugs, which attributes to 46.3% of total incarcerations in the United States.