Paul Zilly COMPAS sentencing risk assessment

Accused thief Paul Zilly was landed with a jail sentence based directly on a risk assessment by a controversial violence recidivisalgorithm 

Zilly was accused of stealing a push lawnmower and other tools in north Wisconsin. Zilly had long struggled with a meth habit and in 2012 he'd been working toward recovery with the help of a Christian pastor when he relapsed and committed the theft, according to an investigation by ProPublica.

Having scored as a high risk for violent recidivism by the Correctional Offender Management Profiling for Alternative Sanctions (COMPAS) tool, Zilly was sent to prison for two years and given three years of supervision, despite his lawyer agreeing to a plea deal with prosecutors in which the state would recommend one year in a county jail followed by supervision to ensure Zilly would 'stay on the right path.'

In his sentencing, Judge James Babler referenced the score generated by COMPAS, which calculated Zilly as high risk for future violent crime and medium risk for general recidivism. 

However, at an appeals hearing, Babler reduced Zilly's prison sentence to 18 months after he had heard testimony given by Northpointe CEO Tim Brennan, who said that he had not designed his software to be used in sentencing and that his focus was on 'reducing crime rather than punishment.' 

According to Judge Babler, he would have given a lower sentence. 'Had I not had the COMPAS, I believe it would likely be that I would have given one year, six months.' he said at the appeal.

Paul Zilly’s case brought attention to the use of the Correctional Offender Management Profiling for Alternative Sanctions (COMPAS) tool in sentencing decisions12. COMPAS is an algorithm designed to assess a defendant’s risk of recidivism, i.e., the potential risk that the defendant will commit a crime in the future.

In Zilly’s case, despite his lawyer agreeing to a plea deal with prosecutors in which the state would recommend one year in a county jail followed by supervision, the COMPAS tool scored him as a high risk for violent recidivism3. As a result, Zilly was sent to prison for two years and given three years of supervision.

➕ The use of COMPAS in sentencing was upheld by the Supreme Court of Wisconsin in State v. Loomis, with the court controversially ruling that the use of the tool did not violate the defendant’s due process rights to be sentenced individually and using accurate information.

Research, advocacy 🧮

• Rowe E.A., Prior N. (2022). Procuring Algorithmic Transparency (pdf)

• Collins E. (2018). Punishing Risk (pdf)

• Carlson A.M (2017). The Need for Transparency in the Age of Predictive Sentencing Algorithms (pdf)

Investigations, assessments, audits 🧐

• ProPublica (2016). Machine Bias

News, commentary, analysis 🗞️

• https://www.sciencefocus.com/future-technology/can-an-algorithm-deliver-justice/

• http://archive.jsonline.com/news/crime/risk-scores-attached-to-defendants-unreliable-racially-biased-b99732973z1-381306991.html

• https://www.theatlantic.com/ideas/archive/2019/06/should-we-be-afraid-of-ai-in-the-criminal-justice-system/592084/

• https://boingboing.net/2016/05/24/algorithmic-risk-assessment-h.html

• https://theamericanscholar.org/the-future-of-silicon-valley/

• https://digital.hbs.edu/platform-rctom/submission/man-or-machine-who-holds-the-stronger-suit-in-the-courtroom/

• https://ilr.law.uiowa.edu/print/volume-103-issue-1/the-need-for-transparency-in-the-age-of-predictive-sentencing-algorithms/

• https://www.cdotrends.com/story/17205/pleading-your-case-ai-judge

• https://www.criminallegalnews.org/news/2020/jan/21/compute-or-not-compute-algorithm-driven-ai-criminal-justice-system/

• https://www.theatlantic.com/ideas/archive/2019/06/should-we-be-afraid-of-ai-in-the-criminal-justice-system/592084/

• https://urbanmilwaukee.com/2017/01/05/murphys-law-justice-system-uses-biased-test/