HRDAG at FAT* 2020: Pre-Trial Risk Assessment Tools

On January 29, at the Conference on Fairness, Accountability, and Transparency (FAT*) held in Barcelona, HRDAG’s Kristian Lum will present a new paper that addresses the question of how police officer booking decisions affect pre-trial risk assessment tools relied upon by judges to make pre-trial release decisions. The paper looks at a popular risk assessment tool known as the Arnold Public Safety Assessment (PSA) and uses data from a pilot run of the tool in San Francisco, California.
The key finding of the paper is that booking charges that do not result in a conviction (that is, charges that are dropped or result in an acquittal) increased the recommended level of pre-trial supervision in around 27 percent of cases evaluated by the tool. In other words, it is fairly common that a person is booked on charges that are not sufficiently supported by the facts of the case to result in a conviction—or overbooked—and these charges alone cause the risk assessment tool to recommend to judges that the defendants have greater supervision before the trial. 
The paper, “The impact of overbooking on a pre-trial risk assessment tool,” was co-authored by Kristian, HRDAG executive director Megan Price, and San Francisco’s newly elected District Attorney, Chesa Boudin.
“We were delighted to co-author this with Chesa, San Francisco’s newly elected DA, and we’re excited about continued collaborations with both the Public Defender’s Office and District Attorney,” says Megan. 
FAT* is an annual conference dedicated to bringing together a diverse community to investigate and tackle issues such as machine learning, and the ethical, moral, social, and policy implications of big data and artificial intelligence. The conference will livestream, and the paper authored by Lum, Boudin and Price is available here.

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