Skip Navigation

How Many Americans Are Unnecessarily Incarcerated?

Published: December 9, 2016

Nearly 40 percent of the U.S. prison popu­la­tion — 576,000 people — are behind bars with no compel­ling public safety reason, accord­ing to a new report from the Bren­nan Center for Justice at NYU School of Law. The first-of-its-kind analysis provides a blue­print for how the coun­try can drastic­ally cut its prison popu­la­tion while still keep­ing crime rates near historic lows.

Read the Preface

Read the Fore­word

Preface by Inimai Chet­tiar

This Report’s Purpose

While mass incar­cer­a­tion has emerged as an urgent national issue to be addressed, the reforms currently offered are dwarfed by the scale of the prob­lem. The coun­try needs bolder solu­tions.

How can we signi­fic­antly cut the prison popu­la­tion while still keep­ing the coun­try safe? This report puts forth one answer to that ques­tion. Our path forward is not offered as the only answer or as an abso­lute. Rather, it is meant to provide a start­ing point for a broader discus­sion about how the coun­try can rethink and revamp the outdated senten­cing edifice of the last four decades. 

This report is the product of three years of research conduc­ted by one of the nation’s lead­ing crim­in­o­lo­gists, exper­i­enced crim­inal justice lawyers, and stat­ist­ical research­ers. First, we conduc­ted an in-depth exam­in­a­tion of the federal and state crim­inal codes, as well as the convic­tions and sentences of the nation­wide prison popu­la­tion (1.46 million pris­on­ers serving time for 370 differ­ent crime categor­ies) to estim­ate how many people are currently incar­cer­ated without a suffi­cient public safety rationale. We find that altern­at­ives to incar­cer­a­tion are more effect­ive and just penal­ties for many lower-level crimes. We also find that prison sentences can safely be shortened for a discrete set of more seri­ous crimes. 

Second, based on these find­ings, we propose a new, altern­at­ive frame­work for senten­cing groun­ded in the science of public safety and rehab­il­it­a­tion.

Many have argued that regi­men­ted senten­cing laws should be elim­in­ated and replaced with broad judi­cial discre­tion. Others counter that this would rein­state a system wherein judges are free to deliver vastly diver­gent sentences for the same crime, poten­tially exacer­bat­ing racial dispar­it­ies and perpetu­at­ing the tradi­tion of harsh sentences.

This report proposes a new solu­tion, build­ing on these past propos­als. We advoc­ate that today’s senten­cing laws should change to provide default sentences that are propor­tional to the specific crime commit­ted and in line with social science research, instead of based on conjec­ture. These defaults should mandate sentences of altern­at­ives to incar­cer­a­tion for lower-level crimes. For some other crimes that warrant incar­cer­a­tion, they should mandate shorter sentences. Judges should have discre­tion to depart from these defaults in special circum­stances, such as a defend­ant’s crim­inal history, mental health or addic­tion issues, or specif­ics of the crime commit­ted. This approach is groun­ded in the premise that the first prin­ciple of 21st century senten­cing should be to protect public safety, and that sentences should levy the most effect­ive, propor­tional, and cost-effi­cient sanc­tion to achieve that goal. It aims to create more uniform sentences and reduce dispar­it­ies, while preserving judi­cial discre­tion when needed. 

Our proposed senten­cing defaults for each crime weigh four factors:

  • Seri­ous­ness: Murder, for instance, should be treated as a far graver crime than writ­ing a bad check.
  • Victim Impact: If a person has been harmed in the commis­sion of a crime, espe­cially phys­ic­ally, weight toward a more seri­ous sentence.
  • Intent: If the actor know­ingly and delib­er­ately viol­ated the law, a more severe sanc­tion may be appro­pri­ate.
  • Recidiv­ism: Those more likely to reoffend may need more inter­ven­tion. Our find­ings and recom­mend­a­tions, determ­ined by apply­ing the four factors above to the prison popu­la­tion, are detailed below. (The rationale for these factors and our full meth­od­o­logy is described in Appendix A.)

Our Find­ings

As depic­ted in Figure 1, this report finds the follow­ing:

  • Of the 1.46 million state and federal pris­on­ers, an estim­ated 39 percent (approx­im­ately 576,000 people) are incar­cer­ated with little public safety rationale. They could be more appro­pri­ately sentenced to an altern­at­ive to prison or a shorter prison stay, with limited impact on public safety. If these pris­on­ers were released, it would result in cost savings of nearly $20 billion per year, and almost $200 billion over 10 years. This sum is enough to employ 270,000 new police officers, 360,000 proba­tion officers, or 327,000 school teach­ers. It is greater than the annual budgets of the United States Depart­ments of Commerce and Labor combined.
  • Altern­at­ives to prison are likely more effect­ive sentences for an estim­ated 364,000 lower-level offend­ers — about 25 percent of the current prison popu­la­tion. Research shows that prison does little to rehab­il­it­ate and can increase recidiv­ism in such cases. Treat­ment, community service, or proba­tion are more effect­ive. For example, of the nearly 66,000 pris­on­ers whose most severe crime is drug posses­sion, the aver­age sentence is over one year; these offend­ers would be better sentenced to treat­ment or other altern­at­ives.
  • An estim­ated 212,000 pris­on­ers (14 percent of the total popu­la­tion) have already served suffi­ciently long prison terms and could likely be released within the next year with little risk to public safety. These pris­on­ers are serving time for the more seri­ous crimes that make up 58 percent of today’s prison popu­la­tion — aggrav­ated assault, murder, nonvi­ol­ent weapons offenses, robbery, seri­ous burg­lary, and seri­ous drug traf­fick­ing.
  • Approx­im­ately 79 percent of today’s pris­on­ers suffer from either drug addic­tion or mental illness, and 40 percent suffer from both.35 Altern­at­ive inter­ven­tions such as treat­ment could be more effect­ive sanc­tions for many of these indi­vidu­als.


Based on these find­ings, this report issues the follow­ing recom­mend­a­tions to safely reduce the prison popu­la­tion. As shown in Figures 1 and 2, these recom­mend­a­tions will decrease the total prison popu­la­tion but ensure that those who have commit­ted the most seri­ous crimes remain behind bars. The major­ity of pris­on­ers remain­ing in the new system would be viol­ent offend­ers (59 percent), up from less than half in the current system (46 percent).

  • Elim­in­ate Prison for Lower-Level Crimes Barring Excep­tional Circum­stances: State legis­latures and Congress should change senten­cing laws to mandate altern­at­ives to prison as the default sentences for certain lower-level crimes. These include drug posses­sion, lesser burg­lary, minor drug traf­fick­ing, minor fraud or forgery, minor theft, and simple assault — offenses that now account for 25 percent of the prison popu­la­tion. Altern­at­ive sanc­tions — such as community service, elec­tronic monit­or­ing, proba­tion, resti­tu­tion, or treat­ment — should be the default for such crimes instead. Judges should have flex­ib­il­ity to depart and impose a prison sentence if certain enumer­ated factors are present — for example, repeat seri­ous offenses or hein­ous circum­stances of the crime.
  • Reduce Sentence Minim­ums and Maxim­ums by Law: State and federal legis­latures should reduce the current minim­ums and maxim­ums prison stays set by laws, or guidelines. These ranges should be propor­tional to the crimes commit­ted, with judges retain­ing discre­tion to depart when appro­pri­ate. We recom­mend that legis­lat­ors consider a 25 percent cut as a start­ing point to determ­ine how to reduce sentences for the six major crimes that make up the bulk of the current prison popu­la­tion: aggrav­ated assault, murder, nonvi­ol­ent weapons offense, robbery, seri­ous burg­lary, and seri­ous drug traf­fick­ing. Sentences would be shorter, but still substan­tial. For example, the aver­age inmate convicted of robbery now serves 4.2 years. A 25 percent cut would reduce the prison stay to 3.1 years. A similar analysis can be applied to other crimes for which prison may be warran­ted to determ­ine whether sentences can be safely shortened.
  • Retro­act­ively Apply Reforms: Current inmates should be permit­ted to peti­tion judges for retro­act­ive applic­a­tion of the two reforms above, on a case-by-case basis. This would allow for safe release of pris­on­ers whose sentences no longer serve a justi­fi­able public safety purpose.
  • Comple­ment­ary Recom­mend­a­tions: Prosec­utors should use their discre­tion to seek altern­at­ives to incar­cer­a­tion or shorter prison stays in line with the recom­mend­a­tions of this report. Further, the nearly $200 billion in savings from imple­ment­ing this report’s recom­mend­a­tions can be rein­ves­ted in proven crime preven­tion tactics and in altern­at­ives to incar­cer­a­tion proven to reduce recidiv­ism.

While the first steps many states have taken toward prison reform are welcome, they have not gone far enough. It took roughly four decades to build mass incar­cer­a­tion. Yet, at current rates of decline, it will take even longer to undo it.

This report provides evid­ence-based find­ings and puts forth one approach to rethink senten­cing that will reduce the dispro­por­tion­ate impact on communit­ies of color, while main­tain­ing hard-won gains in public safety and saving cash-strapped states signi­fic­ant sums. Our goal is to jump-start a conver­sa­tion about how the coun­try can imple­ment specific reforms that are auda­cious enough to truly end mass incar­cer­a­tion.

Inimai Chet­tiar is the director of the Justice Program at the Bren­nan Center for Justice. She direc­ted the research team conduct­ing this report.

Fore­word by Cornell William Brooks

In 1963, the March on Wash­ing­ton marked a turn­ing point in the long fight for civil rights for African Amer­ic­ans. A century after Pres­id­ent Lincoln issued the Eman­cip­a­tion Proclam­a­tion, hundreds of thou­sands converged at his memorial to celeb­rate a century of liber­a­tion and to protest what Rev. Dr. Martin Luther King, Jr. called “the manacles of segreg­a­tion and the chains of discrim­in­a­tion.” In the inter­ven­ing fifty years, we have come a remark­able distance, but the shackles of systemic racism continue to bind communit­ies of color. 

We stand on the front­lines in the fight to build a soci­ety free from racial discrim­in­a­tion. In 2015, we honored the sacri­fices of our forbear­ers and galvan­ized inter­na­tional atten­tion to systemic discrim­in­a­tion with a “Jour­ney for Justice” from Selma, Ala. to Wash­ing­ton, D.C. While national support for this effort provides hope the tide may be turn­ing, it also belies a sad truth: Many of the grave inequal­it­ies we fought decades ago still persist, more than fifty years after the Civil Rights Act. The single greatest injustice that threatens our safety and hinders our progress? Mass incar­cer­a­tion. People of color bear the brunt of our crim­inal justice system in dispro­por­tion­ate and devast­at­ing numbers. This is in part because racial dispar­it­ies exist at all stages of the system, which relies on corros­ive prac­tices that harm people of color. Our communit­ies have already suffered from historic and systemic economic injustice and racially targeted crim­inal justice policies. These wounds have not healed and have been aggrav­ated by the stag­ger­ing number of people trapped in pris­ons over the past forty years. Today, an estim­ated 2.2 million people are locked inside jails and pris­ons. African Amer­ic­ans make up roughly 13 percent of the U.S. popu­la­tion but 37 percent of the nation’s pris­on­ers.1 People with dreams and aspir­a­tions suffer in airtight cells of prison and poverty. But the injustice does not end there. More than half of formerly incar­cer­ated Amer­ic­ans are unem­ployed a year after release. Communit­ies of color are over policed, over-prosec­uted, over-incar­cer­ated and yet under­em­ployed.

If we do not take steps now, Amer­ic­ans of color will forever be releg­ated to a penal and perman­ent under­class, and mass incar­cer­a­tion will continue to cage the economic growth of our communit­ies. We have reached a crisis point, and we need solu­tions. This ground­break­ing report from the Bren­nan Center for Justice offers a path­way to reduce our prison popu­la­tion and its tragic racial dispar­it­ies. It docu­ments the number of people behind bars without rationale, and reveals the unne­ces­sary trauma this causes. It recom­mends real solu­tions that can help end over-incar­cer­a­tion. I urge lawmakers to give deep consid­er­a­tion and deeper commit­ment to this report’s find­ings and recom­mend­a­tions.

This nation must continue to march forward, toward a day when all people are treated based not on the color of their skin but on the content of their char­ac­ter, uncolored and un-stig­mat­ized by a crim­inal record. It is time that we end the plague of mass incar­cer­a­tion.

Mr. Brooks is the Pres­id­ent and CEO of the National Asso­ci­ation for the Advance­ment of Colored People.