Even if that number was in the general ball for black men being arrested, would you automatically assume most didn't actually commit a crime? That the American "system" is mostly to blame for it?
I would assume that most had not committed a crime - at least until the arrest statistics were compared to analogous conviction statistics.
These statistics report ARRESTS - not convictions. Our justice system is based on the philosophy that one is innocent until one is proven guilty. And as far as I know, that applies to people of all races. Do you think it does not?
What about 38% whites?