Understanding the consequences of different sentences can help us decide which aims of sentencing we want to prioritise, writes Dr Ian Marder of the School of Law and Criminology.

    In 2013, the Oireachtas Joint Committee on Justice issued a landmark report calling for Ireland to adopt a 'decarceration strategy'. Back then, Ireland imprisoned 4,068 people, giving us a rate of 88 people in prisons per 100,000 population.

    This meant we relied on imprisonment more often than European neighbours like Germany, the Netherlands, and all the Nordic countries.

    Calls for a ‘decarceration strategy’ – a coordinated plan to reduce imprisonment and increase the use of community-based responses to crime – were not made lightly. Oireachtas members heard evidence that most people in prison were not dangerous, prisons do not assist with rehabilitation, and rising prison numbers reflected political decisions, but did not reduce crime.

    The Committee cautiously proposed reducing the prison population by one-third in 10 years. They suggested using community-based sentences for nonviolent offences and instead of short prison sentences, and structured early releases to help people reintegrate safely.

    Where are we now?

    Twelve years on, Ireland's prison population has now grown over a quarter to 5,322. This trajectory drastically exceeds the latest Department of Justice projections, suggesting Ireland might reach a prison population of 5,282 people by 2030.

    Assuming that Ireland’s population is 5.3 million, our imprisonment rate has risen from 88 to 100 people per 100,000. Rates are important: by controlling for population growth, the rise demonstrates that a person is more likely than ever to be imprisoned, giving rise to massive prison overcrowding.

    Data from 2023 show that most prison sentences in Ireland (78%) are under a year and thousands of people are in prison for nonviolent offences. This raises questions about what we are aiming to achieve, and the consequences of using prison more and more often.

    Why increase or decrease imprisonment?

    Many will wonder: why reduce the use of prison? A common belief is that increased imprisonment lowers crime by deterring people from committing (or recommitting) offences, gives the State the opportunity to rehabilitate people, and keeps us safe. It also metes out justified retribution.

    We need to separate out different rationales for increasing imprisonment to understand whether prisons can achieve them. First, the evidence does not show that making sentences longer deters people from offending in the first place. Increasing sanctions has little influence on behaviour, as we tend to break rules assuming we won’t get caught, without thought as to the consequences of being caught or, for some people, not caring if we are caught or not.

    But can spending longer in prison reduce reoffending by deterring or rehabilitating the people who go? The evidence suggests not: imprisonment usually causes more reoffending than community sentences. Being imprisoned, especially for the first time, disconnects you from things that would help you avoid breaking laws as you mature: employment, housing, family, education. The stigma of imprisonment then makes it even harder to rebuild your life around these later.

    For those in prison who have difficult lives on the outside, underlying causes often include mental health, trauma, homelessness or alcohol and drug addiction. Prison exacerbates such problems, whereas making services accessible during community-based sentences helps address them. It is also more expensive: in 2022, prison cost almost €85,000 per person per year, not including the cost to society and victims of failing to reduce reoffending.

    This is why another possible goal of prison, incapacitation, is also difficult to achieve. Few dispute that there will always be a need to temporarily isolate persons who represent an imminent serious danger to themselves or others. Criminal justice is not the only system we have for this, of course. Some people are detained against their will in psychiatric centres. Through Tusla, children can be held in secure Special Care Units.

    As Ireland knows well, however, institutionalisation, even when purportedly in the person’s own interests, can lead to significant human rights abuses and should be minimised. As prison can increase reoffending anyway, any incapacitative effect is temporary, and must be weighed against the likely consequences and the alternatives. Even serious violence can be prevented in communities if police collaborate intelligently with other services. If we avoid imprisoning people, we avoid the risk that prison causes more harm than it prevents.

    But if a person lacks control to such a degree that the State must isolate them, should the goal of that also be to make them suffer? That brings us to something prison does achieve: retribution.

    Imposition of pain

    We shouldn’t be surprised that prison fails to rehabilitate, given that it is designed with retribution in mind. Retribution is the idea that the State must intentionally impose pain on people who break laws. Deterrence, incapacitation and rehabilitation are all about lowering crime. With retribution, imposing pain through punishment is the priority, even if this increases crime.

    Retribution is a sentencing rationale that many people hold dear. Judges and politicians think that the public want it. Many people assume it helps victims, even though prison doesn’t compensate victims or meet their needs. Meanwhile, victims’ services operate on shoestring budgets, playing second fiddle to big investments in prison expansion.

    Another issue arises if we assume that increasing imprisonment for retributive purposes will also reduce crime. The evidence shows that, generally, these goals are mutually exclusive. If we want less crime, we can place greater emphasis on community justice and reinvest the money we save in services that prevent crime and support victims. If we want sentencing to increasingly prioritise retribution, we have to accept that this will likely create more victims.

    A debate requiring clarity

    People are not wrong if they feel that retribution may be warranted in a given case, or as an overall goal of criminal justice. But we must be clear about the likely outcomes of different approaches when deciding what we want our justice system to prioritise in practice.

    If we cannot prioritise everything, and if our resources are finite, policy debates must be informed by this evidence. Do we want more prisons if this comes at the expense of investing in prevention? Recent public attitudes surveys, including a Red C poll from October 2024, found that most people want investment in policing, prevention, and alternatives to prison. 

    US research asked victims what they prefer. Large majorities favoured investing in services other than prison to make society safer. Ireland can lead the world in meeting victims’ needs if we design systems to do this independently of what happens to the offender.

    Irish criminal justice is at a critical juncture. Speaking to prison officers in May, the Minister for Justice himself noted that some people in prison ‘probably’ don’t need to be there. We need brave leaders to recognise that prison is harmful and develop a decarceration strategy to systematically and ethically reduce our use of imprisonment.

    This piece originally appeared on RTÉ Brainstorm