Massachusetts Prison Classification Tool Found Accurate, But Restrictions Reduce Predictive Power

BOSTON — January 12, 2026 — A Massachusetts legislative commission heard Monday that the state Department of Correction's classification tool accurately predicts institutional misconduct, but that non-discretionary overrides are undermining its effectiveness. The Special Commission on Correctional Consolidation and Collaboration, co-chaired by Sen. Will Brownsberger and Rep. Dan Hunt, received findings from UMass Chan Medical School researchers Dr. Gina Vincent and Dr. Spencer Lawson, who analyzed reclassification records for 7,611 men between 2019 and 2022. The scored classification tool performed well on its own, with violent misconduct below 5 percent over three years, but accuracy degraded once researchers applied non-discretionary restrictions — which affected 43 percent of the sample. The biggest driver was Code C, a civil-commitment restriction applied to 18 percent of all cases. Claire Mazenton of the Mental Health Legal Advisors Committee told the commission the state classifies roughly 30 percentage points more of its prison population to medium security than the national average — and 30 points fewer to minimum.