Berk’s expertise is being sought at nearly every stage of the criminal-justice process. Maryland is running an algorithm like Philadelphia’s that predicts who under supervision will kill—or be killed. The state has asked Berk to develop a similar algorithm for juveniles. He is also mining data from the Occupational Safety and Health Administration to forecast which businesses nationwide are most likely to be breaking OSHA rules. Back in Philadelphia, he is introducing statistics to the district attorney’s office, helping prosecutors decide which charges to pursue and whether to ask for bail. He may also work with the Pennsylvania sentencing commission to help determine whether and how long to incarcerate those convicted of crimes.
Is this a good thing? Berk’s algorithms evaluate offenders not as individuals, but as members of a group, about whom certain statistical probabilities exist. But most of us believe that individuals should be punished for what they do, not who they are. Consider race. In Berk’s experience, no institution has used it as a predictor, but it can enter the algorithm indirectly. Philadelphia, for example, factors in zip code, which often correlates with race.
Moreover, Philadelphia’s algorithm—like most other risk-assessment tools—relies heavily on variables related to the perpetrator’s criminal record. “When you live in a world in which juveniles are much more likely to be stopped—or, if stopped, be arrested, or, if arrested, be adjudicated—if they are black, then all of the indicators associated with prior criminal history are going to be serving effectively as a proxy for race,” said Bernard Harcourt, a law and political-science professor at the University of Chicago, who wrote Against Prediction: Profiling, Policing, and Punishing in an Actuarial Age. By using prior record to predict dangerousness, he insisted, “you just inscribe the racial discrimination you have today into the future.”
Ellen Kurtz has a ready response. “The commission of crime is not randomly or evenly distributed in our society,” she told me. “If you wanted to remove everything correlated with race, you couldn’t use anything. That’s the reality of life in America.” Harcourt counters that actuarial prediction inserts race into the analysis by over-sampling from a high-offending population.
In September, the Supreme Court appeared ready to take sides in the debate. It issued a last-minute stay of Duane Buck’s impending execution in Texas, saying that it would consider reviewing an appeal from his lawyers objecting to an expert’s testimony about Buck’s future dangerousness. Two months later, however, the Court decided not to review the appeal and lifted the stay, thereby allowing the expert’s testimony to stand. What, precisely, did Buck’s lawyers say the expert did wrong? He testified that blacks are more likely to commit violence.