Arnold Ventures, which funded the development of the PSA, engages independent researchers to continuously subject the PSA to rigorous evaluation. Independent evaluators are validating the PSA in jurisdictions across the country to maximize predictive accuracy and minimize disparities.

The results of the studies completed to date demonstrate that the assessment is predictive across different jurisdictions and, in combination with additional system improvements, is often associated with decreases in the use of money bail and increases in pretrial release rates. Further, these studies indicate that in jurisdictions where pretrial release rates have increased, new criminal arrests and missed court appointments have not increased. All studies to date have shown the PSA does not exacerbate racial disparities.

Arnold Ventures is committed to further evaluating the PSA and engaging researchers to conduct broader pretrial research. Through the Advancing Pretrial Policy and Research initiative, an independent researcher will examine implementation of the PSA and other local policies, validate the PSA, and consider improvements across ten jurisdictions. In addition, Arnold Ventures is investing in a broader and more comprehensive pretrial research agenda, including research into jail bookings, pretrial detention, pretrial release conditions, access to effective defense services, and prosecutorial discretion.

The results of completed studies involving the PSA are summarized below (in chronological order, from newest to oldest). This list will be updated as additional research is conducted and published. Notably, many of these studies identify implementation of the PSA as just one of several pretrial improvements that jurisdictions have undertaken. Often in conjunction with implementing the PSA, jurisdictions have, for example, increased the use of citations/summons; expanded the role of defense counsel at first appearance hearings; established or expanded the use of diversion; developed supportive pretrial services; and dramatically reduced the use of secured money bail.

Selected Research Articles

  • The Public Safety Assessment: A Re-Validation and Assessment of Predictive Utility and Differential Prediction by Race and Gender in KentuckyAuthors: Matthew DeMichele, Peter Baumgartner, Michael Wenger, Kelle Barrick, Megan Comfort & Shilpi Misra
    • The authors found the PSA predicts well across all three outcomes—Failure to Appear (FTA), New Criminal Activity (NCA), and New Violent Criminal Activity (NVCA); its predictive abilities fall within what is considered good in the criminal justice field.
    • For NCA and NVCA, the PSA predicts equally well for black and white defendants.
    • For FTA, the PSA predicts differently for black and white defendants in that it assigns black defendants lower risk scores than white defendants who fail to appear at the same rate.
  • What do Criminal Justice Professionals Think About Risk Assessment at Pretrial?Authors: Matthew DeMichele, Peter Baumgartner, Kelle Barrick, Megan Comfort, Samuel Scaggs & Shilpi Misra
    • 79 percent of judges surveyed report that the PSA’s recommendation “always” or “often” informs their decision making.
    • 61 percent of judges, prosecutors, public defenders, and pretrial officers surveyed report they “often” agree with the PSA’s recommendation.
  • The Intuitive-Override Model: Nudging Judges Toward Pretrial Risk Assessment InstrumentsAuthors: Matthew DeMichele, Megan Comfort, Shilpi Misra, Kelle Barrick & Peter Baumgartner
    • The authors’ findings indicate that judges perceive a tension when reconciling the actuarial aspect of the PSA and their experience-based inclination to learn about defendants’ lives as a way of assessing risk through determinations of culpability and blameworthiness.
    • Authors recommend the creation of researcher-judge feedback loops along with increased transparency of model development.
  • Assessing Risk Assessment in ActionAuthor: Megan Stevenson
    • Stevenson’s paper shows that a 2011 law making risk assessment a mandatory part of the bail decision in Kentucky led to a significant change in bail setting practice, but only a small increase in pretrial release.
    • Risk assessment had no effect on racial disparities in pretrial detention once differing regional trends were accounted for.
    • Stevenson calls for additional research and experimentation to help risk assessment produce larger benefits.