[JangoSteve]

Your analysis above is a prime example of how dangerous statistics can be when not properly considered. Even if we took your numbers above as truth, it actually does not indicate that the system isn't biased. In order to determine that you'd need to know what percentage of each group _not_ labeled as high risk never re-offended. You're only analyzing the true positive rate without taking into account the false negative rate. You'd need to know how many people in each group that weren't labeled went on to re-offend.

Thankfully, the article I linked to looked at both:

                                               White  African American
    Labeled Higher Risk, But Didn’t Re-Offend  23.5%  44.9%
    Labeled Lower Risk, Yet Did Re-Offend      47.7%  28.0%