There is little research evidence to suggest that prison is a deterrent. The opposite is often true: once someone has served a sentence of imprisonment, they are more likely to re-offend. The likelihood of being caught is a more effective deterrent than the prospect of a long prison sentence.
There has been a 20 per cent increase in the prison population between 2002 and 2018, with the number of people in prison at a record 11 million.
Evaluations of rehabilitative-focused alternatives to detention show that they can reduce re-offending rates more effectively than prison sentences, by better addressing the reasons why people offend and making communities safer. In 2019, an international review found that recidivism rates are typically lower for people who have served a community sentence, compared to that reported among people who had served prison time.
The range of alternatives is wide and should be tailored to suit the individual needs of each case. Alternatives to prison sentences include fines, drug treatment and supervision orders, electronic monitoring with conditions and supervision, restorative justice measures involving the victim and community, specific programmes to deal with the causes of crime (e.g. treatment programmes), probation orders, community service, and conditional and suspended sentences.
Most people who have been in prison re-enter society no better equipped to avoid a life of crime than when they were first arrested. Most have poor education, limited employment experience and dysfunctional families. They often suffer from alcohol or drug addiction. After a prison sentence, they experience social stigma, have no money and find it hard to find a job or somewhere to live. Alternatives to prison can provide solutions to at least some of these problems. Non-custodial sentences also help offenders to retain the support networks they have in the community, essential to rehabilitation.
The cost of imprisoning someone is generally far higher than the costs of a non-custodial sentence. Spending on an ever-growing prison population diverts funds from essential social, economic and healthcare services. This is compounded by the lack of funding provided to criminal justice systems more broadly, with countries spending on average less than 0.3 per cent of GDP on prisons.
People in pre-trial detention are legally presumed innocent until proven guilty, and such detention should be a measure of last resort (see UN Tokyo Rules). At the pre-trial stage of the criminal justice process, detainees are particularly vulnerable to violence, abuse and intimidation by interrogators. Alternatives, such as bail, reporting or curfews, help to avoid the risk of potential physical and mental harm, preserve the presumption of innocence, and give the defendant a better chance of preparing for and receiving a fair trial.
A prison sentence often punishes families and children as well as the person detained. It is estimated that millions of children worldwide have a parent in prison and approximately 19,000 are living in prison with their parent, most often their mother. Where the family member in prison is the breadwinner, families outside often face serious financial hardship, if not destitution.