Britain should bang up the trouble-makers, but let's turn them round, too: Boris Johnson

It is a stunning fact that fully three quarters of those arrested for the August riots turn out to have had a previous criminal record – and 83 per cent of them were "known to the police". But what is even more stunning is that about half of these characters had been convicted of an average of 15 offences – and yet they had not been to prison for any of them. That's a lot, isn't it, 15 offences?

You have to wonder what on earth is wrong with a system where people can commit 15 offences and walk free every time, ready to go out and do it again, all set to get involved in a riot as soon as they think the police are occupied elsewhere. If you were a police officer, and you'd arrested these people – and gone to the immense difficulty of producing the evidence necessary to secure their convictions without infringing their human rights – I reckon you might be getting a bit frustrated. You might think that these thugs and creeps were thumbing their nose at justice, and you would be right.

It is very hard to ask our police to inculcate a fear of the law, when the perps know fine well that they can offend and re-offend 15 times, often violently, without coming anywhere near a jail. The sad truth is that our penal system – our prisons – are now under such pressure that we are issuing cautions to the kind of people who should really be inside. As the London Evening Standard revealed in a recent Freedom of Information request, there were a total of 16,447 violent offenders who received nothing more than a caution in the 12 months to March 2011 – and that was in London alone.

Of those cautions, 6,719 were for carrying out an assault with injury, and a further 5,162 were for common assault. I bet you are wondering how many of those violent offenders went on – after their slap on the wrist from society – to get involved in the looting and destruction of property in the August disturbances. And I bet the answer is that there were quite a few. We have a general belief in this country that we bang up more people than the rest of Europe, and it is certainly true that the prison population is at an all-time high.

But the wretched truth is even worse than that. We imprison fewer people, per crime, than Ireland, France, Spain, the Netherlands, Greece and Portugal. We may be locking up huge numbers, but the reality is that there are even larger numbers who are effectively getting away with it – and that is why I believe we would be totally wrong to relax our custodial policies and cut sentences across the board. more