On July 19, 2019, the National Institute of Justice (NIJ), a research arm of the U.S Department of Justice’s Office of Justice programs, published a report to accompany the release of PATTERN as a new risk and needs assessment tool that fulfills the First Step Act’s statutory requirement to assign a “recidivism score” to each incarcerated person which predicts their risk of committing crimes three years after release. This expert commentary specifically addresses fundamental, technical problems with PATTERN. Beyond the technical flaws outlined in this comment, a broader and growing body of research questions the validity, ethics, and efficacy of actuarial risk assessments. The PATTERN risk assessment will produce distorted results and is ill-suited as a diagnostic tool to inform risk reduction programming.