COMPAS (software)

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COMPAS, an acronym for Correctional Offender Management Profiling for Alternative Sanctions, is a case management and decision support tool developed and owned by Northpointe (now Equivant) used by U.S. courts to assess the likelihood of a defendant becoming a recidivist.[1][2]

Risk Assessment[edit]

The COMPAS software uses an algorithm to assess potential recidivism risk. Northpointe created risk scales for general and violent recidivism, and for pretrial misconduct. According to the COMPAS Practitioner's Guide, the scales were designed using behavioral and psychological constructs "of very high relevance to recidivism and criminal careers."[3]

Pretrial Release Risk scale[edit]

Pretrial risk is a measure of the potential for an individual to fail to appear and/or to commit new felonies while on release. According to the research that informed the creation of the scale, "current charges, pending charges, prior arrest history, previous pretrial failure, residential stability, employment status, community ties, and substance abuse" are the most significant indicators affecting pretrial risk scores.[3]

General Recidivism scale[edit]

The General Recidivism scale is designed to predict new offenses upon release, and after the COMPAS assessment is given. The scale uses an individual's criminal history and associates, drug involvement, and indications of juvenile delinquency.[4]

Violent Recidivism scale[edit]

Similar to the General Recidivism scale, the Violent Recidivism score is meant to predict offenses following release. The scale uses data or indicators that include a person's "history of violence, history of non-compliance, vocational/educational problems, the person’s age-at-intake and the person’s age-at-first- arrest."[5] An individual's risk score for violent recidivism is calculated as follows:

Violent Recidivism Risk Score = (age∗−w)+(age-at-first-arrest∗−w)+(history of violence∗w) + (vocation education ∗ w) + (history of noncompliance ∗ w), where w is weight, the size of which is "determined by the strength of the item’s relationship to person offense recidivism that we observed in our study data."[6]

Current Applications[edit]

COMPAS has been used in a variety of places, including Broward County of Florida, the State of New York, the State of Wisconsin, and the State of California, among others.[7]

Legal Rulings[edit]

In July 2016, the Wisconsin Supreme Court ruled that COMPAS risk scores can be considered by judges during sentencing, but there must be warnings given to the scores to represent the tool's "limitations and cautions."[7]


  1. ^ Sam Corbett-Davies, Emma Pierson, Avi Feller and Sharad Goel (October 17, 2016). "A computer program used for bail and sentencing decisions was labeled biased against blacks. It's actually not that clear". The Washington Post. Retrieved January 1, 2018.CS1 maint: Multiple names: authors list (link)
  2. ^ Aaron M. Bornstein (December 21, 2017). "Are Algorithms Building the New Infrastructure of Racism?". Nautilus. No. 055. Retrieved January 2, 2018.
  3. ^ a b Northpointe 2015, p. 27.
  4. ^ Northpointe 2015, p. 26.
  5. ^ Northpointe 2015, p. 28.
  6. ^ Northpointe 2015, p. 29.
  7. ^ a b Kirkpatrick, Keith (2017-01-23). "It's not the algorithm, it's the data". Communications of the ACM. 60 (2): 21–23. doi:10.1145/3022181.