Would shorter prison sentences ‘spark a crime wave'? Here's what the evidence says

Independent

23-05-2025

The final report of the Independent Sentencing Review has proposed the most significant reform of sentencing and punishment in England and Wales since the 1990s.
The review, chaired by former Conservative justice secretary David Gauke, calls for a number of changes to address the crisis of overcrowding in prisons. These include using fewer and shorter prison sentences, enhanced opportunities for early release based on good behaviour, and more use of community sentences.
The government has already accepted most of the recommendations in principle, though many will require legislation to bring them into effect. The justice secretary, Shabana Mahmood, has said that the most serious offenders should not be eligible for an earlier release under the proposals.
Prisons in England and Wales have been at or near capacity for a number of years, and frequently exceed their safe capacity. Official data shows that the current adult prison population is estimated to be around 87,700, compared with a maximum operational capacity of around 88,800. However, maximum capacity figures are only recorded annually, and the poor conditions of the prison estate mean the usable maximum may often be lower at any given time.
Without reforms to sentencing, the prison population is projected to increase to up to 105,000 by 2029.
In September 2024, prison overcrowding resulted in the emergency early release of around 1,700 prisoners serving sentences of less than five years who had served 40% of their sentence. They would ordinarily have not been eligible for early release until they had served 50% of their sentences.
The Gauke review was commissioned to create a more sustainable solution to prevent further emergency measures. However, both the review and the emergency measures have come under criticism, namely that dangerous offenders will be released and communities and victims will be at risk. The shadow home secretary, Robert Jenrick, has claimed that the most recent proposals will 'spark a crime wave'.
So, will shorter sentences make communities less safe?
What does the evidence say?
A core recommendation is that custody should be used only as a last resort. It calls for sentences of less than 12 months to only be given in exceptional circumstances, for example, where the offender is known to pose a high level of risk to a specific victim despite being sentenced for a less serious offence.
The research on short-term imprisonment consistently shows that it is ineffective for a number of reasons. Short prison sentences are disproportionately expensive, especially when compared with community sentences. The offenders serving them have committed relatively minor offences, so pose a low risk other than in exceptional cases.
Perhaps the most significant finding is the fact that the shorter the sentence, the higher the reoffending rate. Reoffending is around 55% for prisoners sentenced to less than 12 months, compared with an overall rate of 27.5%. If reoffending can be reduced by using more effective sentences, communities will be safer.
Another key proposal is the 'earned progression model'. Under this, most prisoners (except those sentenced for specified serious sexual or violent offences) would be eligible for release after serving one-third of their sentence. They must have engaged constructively with the prison regime.
They would then be supervised intensively in the community by probation services until they had served two-thirds of their sentence. After this, they would not be actively supervised.
Prisoners who fail to engage constructively would not be eligible for release until the halfway point of their sentence. Under the early release policy introduced by the government in September 2024, these prisoners would be released after serving just 40% of their sentences.
There is a sound evidence base for incentivising good behaviour in prison, rather than simply punishing bad behaviour. It is shown to help prisoners develop a sense of autonomy and accountability for their actions. This can help them abstain from reoffending once released.
A focus on effective rehabilitation, rather than punishment alone, runs through the review. For example, recommendations for improved and targeted substance abuse and mental health treatment.
There is widespread evidence across jurisdictions which suggests that a focus on rehabilitation, and not longer prison sentences, is what reduces overall crime levels and makes communities safer. It also makes economic sense.
The chief inspector of prisons, Charlie Taylor, made clear in his most recent annual report in September 2024 that a fundamental reorientation of prisons towards rehabilitation is needed in order to reduce overall crime levels.
The Howard League for Penal Reform has also welcomed the proposals in the sentencing review.
Concerns
Victims groups have raised concerns about the risk of sex offenders or domestic abusers being released early, even under the current regime. The review recommends strengthening protections for victims, for example, by expanding specialist domestic abuse courts and tagging for all perpetrators of violence against women and girls.
More controversially, it recommends increasing trials into the use of voluntary chemical castration for serious sex offenders. The justice secretary is reported to be considering the use of mandatory chemical castration.
Other questions remain around the implementation of the reforms, not least how they would be funded in the current economic climate. The chief inspector of probation, Martin Jones, has warned that without better funding and other reforms in the probation service, the proposals in the Gauke review would be 'catastrophic'. The review recommends investing in the strained probation service, and bringing in third-sector organisations to support it.
These are ambitious reforms that would require a considerable investment in the probation service, prisons, community rehabilitation and technology. There are also emerging human rights concerns about the adoption of advanced AI by probation services, as is recommended by the review.
Ultimately, there is little evidence to suggest that fewer prisoners and shorter sentences will make communities less safe. It is ineffective rehabilitation leading to reoffending which comes at a considerable social and economic cost.