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

  • Evaluation of Pretrial Justice System Reforms That Use the Public Safety Assessment: Effects in Mecklenburg County, North Carolina (2019)Authors: Cindy Redcross, Brittany Henderson
    • The PSA and related policy changes were associated with a decrease in the use of money bail and an increase in individuals released on their own recognizance.
    • The greatest impact on pretrial release conditions occurred at the initial magistrate hearing, before the PSA is completed; researchers suggest the PSA sparked a change in culture that contributed to this effect.
    • Following implementation of the PSA, Mecklenburg County released more people pretrial but did not see an increase in missed court appointments or new criminal charges.
  • New Jersey Courts, 2018 Report to the Governor and the Legislature (2019)Author: Glenn A. Grant, J.A.D.
    • Two years after the PSA and other criminal justice improvements were implemented, more than 6,000 fewer people are held pretrial in New Jersey’s jails, compared to the pre-implementation timeframe.
    • More than 70 percent of people charged with a crime are released on a summons pending the disposition of their cases, without first being placed in jail.
    • Although more people are released pretrial in New Jersey after the changes, the rates of new criminal arrests and court appearance for individuals released pretrial remain virtually the same.
  • Bail Reform in Cook County: An Examination of General Order 18.8A and Bail in Felony Cases (2019)Author: Office of the Chief Judge, Circuit Court of Cook County
    • The Cook County jail population declined by 42 percent after pretrial changes were implemented.
    • The proportion of people who received a recognizance bond more than doubled, and the increase was highest among minority groups.
    • Over 80 percent of people made all of their court appearances and remained charge-free while on pretrial release.
  • The Public Safety Assessment: A Re-Validation and Assessment of Predictive Utility and Differential Prediction by Race and Gender in Kentucky (2018)Authors: Matthew DeMichele, Peter Baumgartner, Michael Wenger, Kelle Barrick, Megan Comfort & Shilpi Misra
    • 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? (2018)Authors: Matthew DeMichele, Peter Baumgartner, Kelle Barrick, Megan Comfort, Samuel Scaggs & Shilpi Misra
    • Seventy-nine percent of judges surveyed report that the PSA’s recommendation “always” or “often” informs their decision making.
    • Sixty-one percent of judges, prosecutors, public defenders, and pretrial officers surveyed report that they “often” agree with the PSA’s recommendation.
  • The Intuitive-Override Model: Nudging Judges Toward Pretrial Risk Assessment Instruments (2018)Authors: Matthew DeMichele, Megan Comfort, Shilpi Misra, Kelle Barrick & Peter Baumgartner
    • 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 Action (2018)Author: Megan Stevenson
    • 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.
  • Yakima County, Washington Pretrial Justice System Improvements: Pre- and Post- Implementation Analysis (2017)Author: Claire M.B. Brooker
    • Judges decreased their use of secured money bond, relying far more heavily on recognizance in the post-implementation time period.
    • While the release rates for whites did not differ significantly between the pre- and post-implementation time periods, the rates increased significantly for Latino/Hispanic and other groups (from 49 percent to 75 percent and 41 percent to 65 percent, respectively).
    • The overall pretrial release rate increased from 53 percent to 73 percent with no statistically significant change in new arrest and court appearance outcomes.