More jail time not a deterrent as criminals don’t think police will catch them

Longer prison sentences do not work as a deterrent because criminals do not believe they will be caught with police detection rates so low, according to research by the judicial body that oversees sentencing.

A major study by the Sentencing Council said that the “low risk of detection” undermined “any deterrent effect” that longer sentences had on criminals.

It said this was one of five reasons why there was “no strong evidence” to support longer sentences having a “general deterrent effect” on offenders.

“Moreover, we note that some have argued it is time to accept that sentence severity has no effect on the level of crime in society,” said the council.

The latest Home Office figures show police are solving the lowest proportion of crimes on record - as overall offences have hit a new high. Only 5.4 per cent of all crimes resulted in a charge in the year to June, equivalent to just over one in 20 offences being solved. That is more than half the rate six years ago.

By contrast, the average custodial sentence length for all indictable offences has reached 25.7 months in the year to March 2022, up from 16.8 months in 2012, according to Ministry of Justice (MoJ) figures. It follows successive crackdowns on sentencing in successive criminal justice bills by Tories and Labour.

The sentencing council said as well as detection rates, severe sentences could also only deter if offenders knew about them and understood them but research suggested there was “limited understanding” of them among defendants.

Another reason highlighted by the council was that a lot of crime was carried out by people with low self-control, who were highly impulsive and underestimated the consequences of their actions.

“Deterrence-based policies assume that offenders make at least broadly rational decisions, ‘giving some thought to benefits and costs’, whereas research shows that a myriad of psychological and situational factors mean that would-be criminals very often depart from normatively rational behaviour,” said the council.

Many offenders also set more store by “peer group influence and fear of lost respect or social standing” among the criminal fraternity than their fear of facing a long prison term.

The council said that tougher sentences appeared to have little effect not only generally but also in deterring specific individuals from committing crimes.

“There is evidence that sentence enhancements (that is, increases in sentence severity) for those with prior records do not appear to produce a deterrent effect in terms of reductions in rates of reoffending,” said the council.

“For example, in the context of burglary, research with offenders found that assistance with drug misuse rather than the deterrent effects of punishment was the most common reason given for reducing offending.

“Even the more draconian ‘three strikes’ rules in the USA (whereby even three relatively minor offences can lead to prison sentences of between 25 years to life) do not seem to be effective in producing deterrent effects.”

The council said there was even less evidence that “short, sharp shock” punishments for young offenders were effective as teenagers and young people aged over 18 “may still be in a formative phase of their life where deterrent effects as less likely (until as late as 25-30 in terms of neurological development)”.

The council said its review of research suggested short prison sentences under 12 months were less effective than other punishments such as suspended jail terms or community sentences.

It said “certain requirements” of community or suspended sentences such as treatment for drug or drink addiction “may be more effective at promoting positive outcomes than others”.

“The evidence against the effectiveness of short custodial sentences is amongst the most robust. There is also good evidence on what is effective in certain circumstances (for example in cases involving addiction or mental health issues),” concluded the council.

“The council will consider undertaking work with offenders to understand which elements of their sentence may have influenced rehabilitation. Additionally, further research into ‘what works’ for different sectors of the population (for example different ethnicities and genders) would be beneficial.”