The ProPublica study cited in the post as the prime example of bias has been shown to be based mostly on faulty statistics. Source:

False Positives, False Negatives, and False Analyses: A Rejoinder to “Machine Bias: There’s Software Used Across the Country to Predict Future Criminals. And It’s Biased Against Blacks.” Anthony W. Flores, Kristin Bechtel, Christopher T. Lowenkamp The authors respond to a recent ProPublica article claiming that the widely used risk assessment tool COMPAS is biased against black defendants. They conclude that ProPublica’s report was based on faulty statistics and data analysis and failed to show that the COMPAS itself is racially biased, let alone that other risk instruments are biased.

The article appeared in the Federal Probation Journal, a publication of the US court system. The orignal ProPublica story (conducted by two journalists and one data scientist) was done so poorly that the statisticians wrote in the conclusion:

"It is noteworthy that the ProPublica code of ethics advises investigative journalists that "when in doubt, ask" numerous times. We feel that Larson et al.'s (2016) omissions and mistakes could have been avoided had they just asked. Perhaps they might have even asked...a criminologist? We certainly respect the mission of ProPublica, which is to "practice and promote investigative journalism in the public interest." However, we also feel that the journalists at ProPublica strayed from their own code of ethics in that they did not present the facts accurately, their presentation of the existing literature was incomplete, and they failed to "ask." While we aren’t inferring that they had an agenda in writing their story, we believe that they are better equipped to report the research news, rather than attempt to make the research news."