John F. Pfaff · 2017

Locked In

The True Causes of Mass Incarceration—and How to Achieve Real Reform

Rough AI truth score

75/100

Pfaff convincingly corrects a common reform narrative: drug convictions alone cannot explain the prison population, violent offenses matter, and largely opaque county prosecutors deserve far more attention. His stronger prosecutor-centered causal account is plausible but contested because police, legislatures, judges, sentencing, crime, budgets, parole, and local heterogeneity interact.

Based on three central claims · high confidence

The three claims

01Supported

Ending incarceration for drug offenses alone cannot produce deep decarceration because people convicted of violent offenses make up a large share of state prisoners.

Official prison composition data supports the arithmetic: state prisons hold most prisoners, and violent offenses comprise a large share of that stock. Categories hide wide variation in conduct and risk, and drug policy still affects admissions, supervision, communities, and racial inequality.

Bureau of Justice Statistics: Corrections National Academies: The Growth of Incarceration

02Mostly supported

Prosecutorial charging decisions became more aggressive in important periods and substantially shape prison admissions through leverage over pleas and sentencing exposure.

Empirical work supports prosecutors as consequential gatekeepers, with charging and plea decisions affecting outcomes after arrest. Data is unusually sparse, trends differ across counties and offenses, and observed filing rates can reflect police referrals, law, evidence, staffing, and crime composition.

Michigan Law Review: Prosecutors Matter Southern California Law Review: Prosecutorial Power

03Mixed

Local prosecutors are the primary overlooked cause of the rise of mass incarceration and therefore the central lever for reversing it.

Prosecutors are undermeasured, politically important, and able to change charging and diversion quickly. Reviews challenge monocausal attribution: sentencing statutes, policing, judicial behavior, parole, crime changes, state finance, prison capacity, and county variation all contribute and may constrain reforms.

Michigan Law Review: A Reassessment of Locked In National Academies: The Growth of Incarceration

Other claims worth checking

County-level criminal justice deserves more transparent data and political scrutiny.
Reform must confront punishment for violent offenses rather than relying on low-level drug cases alone.

What this number means. It is an AI-generated first-pass judgment of three central factual or causal claims—not a rating, exhaustive fact-check, or human peer review. Claim credits are 100% for supported, 75% for mostly supported, 50% for mixed, and 25% for weak, then averaged and rounded. Lower confidence means the score should move more as better evidence arrives.

Method three-central-claims/0.1.0 · checked 2026-09-01 · 3/3 selected claims assessed · method and source audit