Predictive policing predicts police harassment, not crime / Boing Boing

/predictive-policing-predicts-p.html

  • Predictive policing predicts police harassment, not crime / Boing Boing
    http://boingboing.net/2016/08/18/predictive-policing-predicts-p.html

    In Chicago, the “Heat List” system is used to direct policing resources, based on data-mining of social media to identify potential gang-members; the model tells the cops where to go and who to arrest, and is supposed to reduce both violent crime and the likelihood that suspects themselves will be killed — but peer-reviewed analysis (Scihub mirror) of the program shows that while being on the Heat List increases your chances of being harassed and arrested by Chicago PD, it does not improve crime rates.

    • In the paper, published in the Journal of Experimental Criminology, Rand Corporation researchers conclude that “once other demographics, criminal history variables, and social network risk have been controlled for using propensity score weighting and doubly-robust regression modeling, being on the SSL did not significantly reduce the likelihood of being a murder or shooting victim, or being arrested for murder” but “individuals on the list were people more likely to be arrested for a shooting regardless of the increased contact.

      In other words, predictive policing predicts the police, not the crime. Moreover, as is so often the case, racist training data produces racist predictive models, which allow racist institutions to claim to be undertaking objective and neutral measures while continuing to be totally racist.

    • L’étude en question est accessible ici

      Predictions put into practice : a quasi-experimental evaluation of Chicago’s predictive policing pilot
      http://sci-hub.cc/downloads/6fa8/10.1007@s11292-016-9272-0.pdf
      et son résumé

      Objectives In 2013, the Chicago Police Department conducted a pilot of a predictive policing program designed to reduce gun violence. The program included development of a Strategic Subjects List (SSL) of people estimated to be at highest risk of gun violence who were then referred to local police commanders for a preventive intervention. The purpose of this study is to identify the impact of the pilot on individual- and city-level gun violence, and to test possible drivers of results.

      Methods The SSL consisted of 426 people estimated to be at highest risk of gun violence. We used ARIMA models to estimate impacts on city-level homicide trends, and propensity score matching to estimate the effects of being placed on the list on five measures related to gun violence. A mediation analysis and interviews with police leadership and COMPSTAT meeting observations help understand what is driving results.

      Results Individuals on the SSL are not more or less likely to become a victim of a homicide or shooting than the comparison group, and this is further supported by citylevel analysis. The treated group is more likely to be arrested for a shooting.

      Conclusions It is not clear how the predictions should be used in the field. One potential reason why being placed on the list resulted in an increased chance of being arrested for a shooting is that some officers may have used the list as leads to closing shooting cases. The results provide for a discussion about the future of individual-based predictive policing programs.

      Pfff ! ça fait du bien de voir ce genre d’évidences écrites dans une revue scientifique peer reviewed