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If we don’t know why the prison population is rising, we have little hope of halting the rise

Penelope Gibbs
26 Aug 2017

Who am I to comment on Ministry of Justice sentencing statistics? I am neither a criminologist, lawyer nor statistician. But I know what we don’t know, and worry that too many assumptions are being made without the data to back them up.  So the government has estimated the prison population is likely to increase despite a fall in the number of prisoners on indeterminate sentences, and despite Liz Truss announcing in February that “the prison population has remained relatively stable since 2010 – at around 85,000 people“.  The Ministry of Justice attributes the predicted rise in the prison population “to recent trends in offender case mix, with more serious cases coming before the courts resulting in longer custodial sentences”. As Rob Allen pointed out in his own excellent blog, we don’t actually know that the offences which attract prison sentences are getting more serious, because we don’t have the data. An equally plausible explanation, for which there is at least as much evidence, is that the same offences are being sentenced more severely, for complex reasons.

The Ministry of Justice in their prison population prediction imply that sentence inflation has and will affect a wide variety of sentences. This is a new development since in the same February speech Liz Truss denied that“we have seen sentence inflation across the board. There have been fewer shorter sentences being handed out for offences like shoplifting. What we have seen is significant increases in sentences in particular areas. In fact the biggest driver for prison growth in the last twenty years has been the exposure, pursuit and punishment of sexual offences and crimes of violence, and a toughening up of sentences for these crimes”.

The Lord Chancellor was right. Sentences for violent and sexual offences have shown greatest growth over the long term. But in the last couple of years, the average length of a prison sentence (ACSL) for those offences has gone down, whereas the ACSL for six other offence categories (including fraud and arson) has been going up. The only kind of offence where prison sentences have gone down in length is public order. So while sentence inflation is not “across the board” it is pretty widespread and even the ACSL for theft (which includes shoplifting) has gone up by two weeks since 2007.

Assuming the government doesn’t want their prediction of an increase in the prison population to come true, we need a proper analysis of why such widespread sentence inflation is happening. Rob Allen, I, and many a lawyer think sentencing guidelines are a key driver. And there is some agreement. The Ministry of Justice suggests the new guidelines on early guilty pleas will result in some increase in the prison population, while the Sentencing Council’s own assessment of the impact of burglary guidelines attributes most of the rise in length of sentences to their new guidelines, which came into force in 2012.

The Sentencing Council only occasionally produces this kind of analysis of the impact of guidelines. In 2015, it published an assessment of the impact of their guidelines on sentencing for assault. This also found that the new guidelines had led to sentence inflation, despite their commitment on publication that “the guideline aims to increase the consistency of sentencing whilst leaving the aggregate severity of sentencing unchanged”. So something is going very wrong with the modelling of the impact of new sentencing guidelines (very few of which do the Council predict will increase sentences) and this is leading to more and longer prison sentences.

Clearly guidelines are only one of the reasons for sentence inflation. Another unknown unknown is video justice. This is never mentioned in relation to sentence inflation, but a 2010 MoJ study suggests it is another cause. But we have no data since 2010 on video hearings, so don’t know. Ditto an increase in the number of unrepresented defendants. So we are all only making educated guesses. While the cost to the Ministry of Justice of an increase in the prison population is enormous, the cost of doing a full study of the causes of sentence inflation is tiny in comparison. So why not do this and, meanwhile, impose a moratorium on any new reforms or developments which may increase the prison population, such as new criminal sentences, an expansion of video hearings etc?

NB the Transform Justice survey on video hearings and vulnerable defendants is still open – please fill in if you have an experience of them whether as a participant or practitioner. Rob Allen’s call for reform of the Sentencing Council is here