The School-to-Prison Pipeline
The disciplinary policies that route children from classrooms into courts — and who those policies target.
The short version
- The 'school-to-prison pipeline' describes how zero-tolerance discipline policies, in-school police presence, and criminalization of school behavior funnel students — disproportionately Black and disabled — out of education and into the juvenile and adult criminal justice systems.
- Black students are suspended and expelled at three times the rate of white students for comparable behavior; students with disabilities are disciplined at twice the rate of non-disabled peers.
- A single suspension doubles a student's likelihood of dropping out; dropping out is one of the strongest predictors of future incarceration.
- The evidence on zero-tolerance policies is consistent: they do not improve school safety, they significantly harm academic outcomes, and their effects fall most heavily on the students who already face the greatest structural disadvantages.
What it is
The school-to-prison pipeline is a term describing the set of school disciplinary policies, practices, and systems that push students — particularly Black, Latino, and disabled students — out of educational environments and into the juvenile and criminal justice systems. It is not a single policy but a cluster of interacting forces: zero-tolerance disciplinary codes that mandate suspension or expulsion for a broad range of offenses, the presence of law enforcement officers (School Resource Officers, or SROs) on school campuses who transform behavioral incidents into criminal matters, and the downstream consequences of suspension and exclusion for students whose academic trajectory is disrupted. The pipeline metaphor captures the structural quality of the phenomenon — it is not a series of isolated bad decisions but a system that reliably produces predictable outcomes for specific populations.
Zero-tolerance disciplinary policies expanded dramatically in the 1990s, driven by the moral panic over school violence that followed high-profile incidents and accelerated by the Gun-Free Schools Act of 1994, which required a one-year expulsion for any student bringing a weapon to school and conditioned federal funding on states adopting the policy. Schools and districts extended zero-tolerance logic far beyond weapons to cover drugs, fighting, insubordination, and increasingly vague categories of disruptive behavior. The result was a sharp increase in school suspensions: the number of students suspended from American public schools grew from approximately 1.7 million in 1974 to 3.3 million by 2010. Expulsions, in-school arrests, and referrals to law enforcement also grew substantially during the same period.
School Resource Officers — law enforcement officers stationed in schools — became a major policy lever following Columbine in 1999, with federal funding through the COPS in Schools program accelerating their deployment. By 2017, approximately 43% of all public schools had at least one SRO present. The research on SROs is mixed regarding their effect on school safety but consistent regarding their effect on disciplinary outcomes: schools with SROs have significantly higher rates of arrests for disorderly conduct and other low-level offenses. Behavior that was previously handled by teachers or administrators — a fight in a hallway, a confrontational exchange with a teacher — becomes a criminal matter when law enforcement is the responding party. Students who are arrested at school face both criminal consequences and immediate educational disruption.
The racial and disability disparities in school discipline are among the most robustly documented findings in education research. The Department of Education's Civil Rights Data Collection has found consistently that Black students are suspended at roughly three times the rate of white students for comparable infractions, beginning in preschool — where Black children represent 18% of enrollment but 48% of children receiving more than one out-of-school suspension. Students with disabilities, who represent about 12% of enrollment, represent about 25% of students subjected to restraint or seclusion. These disparities cannot be fully explained by differences in behavior; researchers who have controlled for offense type and severity find that race remains a significant independent predictor of discipline severity.
Why it matters
The academic consequences of suspension are severe and well-documented. A landmark 2011 study by the University of Texas at Austin, analyzing six years of data on nearly one million Texas middle and high school students, found that being suspended or expelled even once more than doubled a student's likelihood of dropping out of school the following year. Students who were repeatedly disciplined were nearly three times as likely to have contact with the juvenile justice system in the year following their first suspension. These outcomes are not random — they are systematically worse for Black students and students with disabilities, the same populations whose baseline educational outcomes are already depressed by other structural disadvantages. Suspension removes students from the environment in which academic progress occurs, while simultaneously flagging them in school records in ways that affect their treatment by subsequent teachers and administrators.
The connection between educational exclusion and incarceration is statistical and structural. Approximately 68% of all males in state and federal prison lack a high school diploma. A student who drops out of school is 63 times more likely to be incarcerated than a four-year college graduate, according to Justice Policy Institute research. The causal arrow runs in multiple directions — factors that contribute to dropping out also contribute to incarceration — but the educational exclusion itself is an independent risk factor. Schools that suspend students heavily produce more dropouts; more dropouts means more young people without the credentials that open labor market alternatives to illegal income; more contact with juvenile justice systems early in life dramatically increases the probability of adult incarceration. The pipeline is not metaphorical — it is a documented empirical sequence.
The effectiveness of zero-tolerance policies as a school safety strategy has been examined in detail and found wanting. A comprehensive review by the American Psychological Association's Zero Tolerance Task Force, published in 2008, found no evidence that zero-tolerance policies make schools safer or improve the school climate, and substantial evidence that they produce harmful outcomes for students, particularly those from marginalized groups. Schools with higher suspension rates do not show better academic outcomes for the students who remain; the evidence suggests the reverse — school climate deteriorates when large numbers of students are excluded. The policies persist not because they work but because they provide administrators with legal cover and appear to send a signal about seriousness that is politically appealing regardless of whether it is educationally effective.
Reform has demonstrated measurable results where it has been seriously implemented. Los Angeles Unified School District eliminated suspensions for willful defiance — the broadest and most discretionary disciplinary category — in 2013. Over the following years, suspensions dropped by over 90% while school climate survey scores improved and academic outcomes did not deteriorate. Oakland Unified, Denver Public Schools, and several other large districts have implemented restorative justice practices — community-based accountability processes that address harm without exclusion — with documented reductions in suspension rates and improvement in the school relationships that the research identifies as protective factors against dropout and incarceration. The evidence that alternatives to exclusionary discipline can work is clear; the political will to implement them at scale in the face of persistent 'tough on discipline' politics is what the research consistently outpaces.
Sources & Further Reading
- Are Zero Tolerance Policies Effective in the Schools? An Evidentiary Review and Recommendations
- Breaking Schools' Rules: A Statewide Study of How School Discipline Relates to Students' Success and Juvenile Justice Involvement
- 2017–18 Civil Rights Data Collection: School Climate and Safety
- Restorative Justice in U.S. Schools: An Updated Research Review
- The School to Prison Pipeline