Less people are serving shorter prison terms, which, Iain Dale explains, is a very good sign

Have you ever had a lightbulb moment? That moment when suddenly the fog lifts and things become clear. That happened to me this week after I read an interview with the retiring chief constable of Durham Constabulary, Mike Barton.

He said that instead of thinking how many criminals we can lock up, and how long for, we should be concentrating instead on how we can best stop criminals reoffending. It's such a simple proposition, but we've so far been blind to it. Instead, we continue to support a criminal justice system which seeks to lock people up for the longest time possible, and then we let them back into society and expect them to become good citizens, having invariably treated them like animals.

Although improving, reconviction rates at Norwich Prison are still running at over 60pc. Think about that. Six in ten of the prisoners who are released go on to reoffend. And it's just in Norwich. Some prisons have far worse figures. Some are as high as 75pc.

In the 12 months following release from prison, 134,000 offences are committed by people who reoffend, with each offender committing an average of 4.05 offences - a 25pc increase over the last 10 years.

Those of us who have been burgled know what it's like to be a victim of crime. You feel personally violated and initially would happily string up the perpetrator from the nearest gibbet. But we have to think with our heads, rather than our hearts. Surely we could all agree that if we had a choice between punitive punishment and preventing reoffending, we would choose the latter, as we wouldn't want anyone else to experience the trauma we ourselves had gone through. Would we? Justice needs to be about more than revenge.

Mike Barton makes the point that crime is nowadays often an inherited family business. He says: "When I started locking up the sons and grandsons of the first burglars I had put away, I started to think this is a fool's errand. All we are doing is regurgitating the same families to inflict further pain on future generations of victims. Well, that isn't want [Sir Robert] Peel wanted us to do."

Barton says the police's job is not just to catch criminals but to stop them committing the crime in the first place. Well, yes, up to a point, but this is not just the job of the police. It's the job of wider society. Early intervention is absolutely vital, which is why SureStart centres and the government's Troubled Families Initiative have been so vital. Most children are not born evil, but they may be born into criminal families. Some will be strong enough to react against the lifestyle, but more often than not, they fall into a life of crime through no fault of their own. It really can be an accident of birth.

Durham Police has pioneered an innovative new scheme called Checkpoint, which offers some criminals the opportunity to avoid prosecution if they agree to work with professionals to stay on the straight and narrow. OK, it all sounds a bit lily-livered and liberal, but we should always judge these things by the results they achieve. All the evidence is that people who've gone through the scheme are 20pc less likely to reoffend.

Short prison sentences do not work. It costs more to keep someone in prison for a year than it does to pay Eton school fees for 12 months. It splits up families with all the consequences of that, both in the short term and long term. There must be other ways of punishing people, rather than sending them to prison for six months or a year.

Let's finish with some good news. The prison population has decreased by 3pc in the last year. The number of prisoners serving shorter sentences is on the decline. The number of people serving longer sentences is on the increase. And yes, that is good news. Serious offences should indeed attract longer sentences.

Email Iain at iain@iaindale.com or follow him on Twitter @iaindale