To minimize injustice, use big data

In recent weeks, there have been questions about the criminal justice system’s use of “big data” in sentencing decisions. Some have even alleged that the practice is “deeply unfair and almost certainly unconstitutional.” This assertion is simply incorrect. There is no question that risk assessment tools are constitutional, provided that they don’t take into account things that are problematic, such as race.  Indeed, when used correctly, these tools can actually help to ensure that all defendants are treated fairly.
At the Laura and John Arnold Foundation, we work to improve decision-making in the criminal justice system in an effort to increase public safety, improve efficiency, and promote the fair administration of justice. We focus on the “front end” of the system – the period that runs from the time an individual is arrested until the case ends.  Our research has shown that the current system – which relies much more on subjective judgment than objective, evidence-based tools – does not adequately protect the public or ensure fairness. Defendants that you would expect to be locked up while awaiting trial – the very highest-risk individuals and those accused of violent crimes – are often released. Meanwhile, low-risk, nonviolent defendants often spend extended periods of time behind bars. This is counterintuitive and unfair, and it is putting our communities at risk.
These findings prompted us to dig deeper and develop strategies that could help to advance the fair administration of justice. We spent more than two years gathering and analyzing data on over a million criminal cases from across the country. We isolated the factors that are the best predictors of whether a given defendant will commit violence, reoffend, or skip court if released before trial. Factors that critics have suggested may be discriminatory – for instance, an individual’s level of education, socioeconomic status, and neighborhood – are not on the list. Rather, our findings show that the best predictors of future misconduct are primarily related to a defendant’s criminal history and current charge.
We then developed a pretrial risk-assessment tool – the Public Safety Assessment-Court.  The PSA-Court provides judges with a data-based risk assessment that they can use to inform their decisions as to whether to detain or release a defendant pretrial. The tool, which does not employ the factors that have recently been critiqued as potentially discriminatory, is helping judges accurately determine which defendants should be detained because of the threat they pose to public safety, and which can be safely released. The PSA-Court is now being used in seven cities and counties across the U.S., as well as throughout the state of Kentucky. Data compiled after the first six months of use in that state show that Kentucky is detaining fewer defendants. And yet even with more people on pretrial release, there has not been a spike in crime. In fact, crime levels in the pretrial period have dropped by nearly 15 percent. And the assessment has proven to be race- and gender-neutral.
This is consistent with what I saw as the attorney general of New Jersey, where we implemented a risk assessment for juveniles who were arrested as part of the Juvenile Detention Alternatives Initiative.  Once the risk assessment was in place, the state reduced the average number of juveniles in detention by more than half, with minorities accounting for nearly 90 percent of this decrease.
In short, evidence-based tools can help reduce crime and cut costs. But their value extends beyond improved public safety and taxpayer savings. Contrary to what others have claimed, evidence-based risk assessments can accurately classify defendants’ risk levels without considering problematic factors. In a society that values equal justice and the presumption of innocence, it is clear that, far from violating the Constitution, risk assessments can help uphold key principles of the American judicial system.
Anne Milgram is vice president of criminal justice at the Laura and John Arnold Foundation.

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