SSN Key Findings

Why Alternatives to Imprisonment are Needed to Prevent Violent Crime in America

Policy field

Connect with the author

University of California-Berkeley

After decades of imprisoning more and more people, U.S. policymakers have recently started focusing on alternative punishments – and shorter sentences for many non-violent offenders have reduced the numbers of prisoners.  But current reforms rarely reach violent offenders who make up nearly half of the population of state and federal prisons on any given day. These offenders are still locked up because it is widely assumed that imprisonment makes communities safer and deters offenders from committing additional violent offenses after release.

Are these assumptions correct?   As controlled environments, prisons do prevent inmates from engaging in violence in the community while they are incarcerated. But researchers dispute and have largely disproven the proposition that incarceration reduces violence over the long run.  Prisons are costly, and the savings the country could realize from imprisoning fewer violent offenders – especially first-time offenders who commit less serious crimes – could be better spent on other strategies to prevent violence.

Prisons and Violence

Studies comparing offenders that some judges give prison sentences while others give only probation demonstrate that imprisonment does little to prevent violence. Many analysts have presumed what is called the “incapacitation effect” – the idea that every time a violent offender is imprisoned, a new violent crime is prevented from occurring in the community. But research shows that imprisonment only prevents crime for a short time, while offenders are behind bars but rarely after they leave prison. New calculations show that to prevent a single individual from committing a future violent crime over a five year stretch, society must imprison more than sixteen convicted violent offenders. The preventative effect of imprisoning a non-violent felony offender is even smaller (specifically, 40 non-violent offenders must be imprisoned to prevent a single individual from committing a violent felony over five years).

This research demonstrates that imprisonment has no preventative effect in the long-term. Over comparable periods of time after offenders are released from prison versus probation, no differences in rates of further offenses are found – a finding that holds whether offenders were originally sentenced for violent crimes or not. In short, imprisonment only prevents violent crime while the prisoner is incarcerated.

Although this research shows that prison sentences are no more effective than probation at preventing crime, some observers nevertheless stress the value letting convicts know that crime begets serious punishment and point out that communities are safer while violent offenders remain incarcerated.  This rejoinder might make sense were it not for the potential negative effects of imprisonment.  For many reasons, imprisonment can actually increase violent behavior after people are released.  This can happen for a variety of reasons. 

  • Harsh environments for inmates can exacerbate their mental health problems, engender cynicism and distrust, and make them more distrustful of law and the legal system after as well as during their time behind bars.
  • While in prison, weaker people may have to learn to fend off victimization by other prisoners by developing more aggressive dispositions or by joining prisoner groups that socialize them into criminal behaviors.
  • Imprisoned inmates are cut off from normal social support networks in community and experience deteriorations in their skills and interpersonal ties that damage their chances of finding jobs and resuming normal lives after they leave prison. 

New violent offenses become more – not less – likely as a result of all these detrimental effects. Researchers compared convicted felons sentenced to prison in Michigan between 2003 and 2006 to other convicted felons sentenced to probation supervision in the community. They found that some people sentenced to prison were more likely to engage in further violence after imprisonment. In short, prison did not work as intended to deter and reduce violence.

Justice Reinvestment – Reinvesting the Savings from Less Imprisonment

If violent offenders are not simply locked up, what could be done instead?  Advocates should push for alternative approaches to violence prevention than the handing down of harsh prison sentences, and policymakers would be wise to institute such changes.

  • Most basically, judges can be urged – and legally enabled – to opt for probation in more of the sentencing cases brought before them.
  • Probation supervision can be accompanied by more active steps to require and help offenders find jobs and other supports for building law-abiding lives.
  • Community based interventions can do more than imprisonment to keep communities safe, and at much lower cost. For example, offenders guilty of less serious acts of domestic violence can be assigned to programs that have proved able to change gender expectations and substantially reduce this kind of offense. Similarly, so-called violence interrupter programs have been shown to reduce clashes between rival gangs or street corner groups.

Are such efforts affordable for states and localities?  They are if understood as “justice reinvestments” of savings from excessive imprisonments. When policymakers consider the costs of incarceration, they should take into account well-documented negative effects on prisoners and their families and communities. Those negative impacts lead to higher taxpayer costs, not just to pay for prisons themselves but also to fund mental health services and school and social work efforts to help damaged children and families. Substantial savings will flow from shrinking prison populations, especially if effective alternatives are found those convicted of the least serious violent offenses.  Those savings, in turn, can be reinvested in the community-based programs known to be more effective at preventing violence and rehabilitating many offenders. Meanwhile, additional research can discover more non-prison approaches that work.    

Read more in David Harding, Jeffrey D. Morenoff, Anh P. Nguyen, Shawn D. Bushway, and Ingrid A. Binswagner, "A Natural Experiment Study of the Effects of Imprisonment on Violence in The Community," Nature Human Behavior, (2019).