The war on drugs weighs particularly heavily on black defendants. The police target their neighborhoods, herding people into a court system where judges are demonstrably harder on black offenders. The report found that nearly half of the counties in Florida sentenced African-Americans convicted of felony drug possession to more than double the jail time of whites — even when their backgrounds were the same.
This may just be a Florida problem, but I doubt it.
https://www.nytimes.com/2016/12/17/opinion/sunday/unequal-se...
From someone I know with personal experience, after they were charged with possession with intent to distribute due to growing pot, they had 3 choices. Go to jail, spend $X on an attorney who would get them probation, or spend 10 * $X on an attorney who would get them off. Both attorneys had perfect records, n>100, at their respective objective.
So, then, why would black people spend less money on legal defense?
300 is a small statistic.
10% of 300 is even smaller.
Science is hard.
At some point Britain thought that wealthy highly-educated people were incapable of being criminals, until time proved them wrong. Science is always evolving.