Analysis: The riots data so far

So what do we know with certainty about the rioters and looters? Are they a criminal, feral underclass or victims of socio-economic blight getting their own back on the rest of society?

Sadly, official statisticians and academics haven't thought of a way to measure such things accurately - as my colleague Mark Easton recently pointed out - but the people with the slide rules in the Ministry of Justice have given us the first real picture of the people now filling up the courts and prisons.

Their new figures cover those who have appeared before the courts. It may be stating the obvious but if someone hasn't had their collar felt, it is difficult to know a lot about them. What's more - the vast majority of those charged - 1,400 defendants - are still in the system. It will be months before we have the full facts on sentencing.

HOW OLD WERE THE RIOTERS AND LOOTERS?

What's clear from the initial analysis is that of those who have come before the courts, under 18s account for a larger proportion than they did among those before the courts in 2010. Just over half of all the people who have appeared in court have been 20 or under.

Drilling further into that figure reveals that about a fifth were aged between 10 and 17 - and 31% were between 18 and 20.

The MoJ looked at the ages of those hauled before the courts for "similar offences" last year and found that 16% were juveniles and 15% were 18 to 20.

Statisticians have counted the types of offences, but given that there were no riots last year, they cannot take into account the actual circumstances of the offending.

What that means is that there is a danger of comparing apples with pears which becomes more important when we look at sentencing a little later.

WHAT DID THEY DO?

The key offence so far has been burglary - and that shows why these events were so different to previous bouts of mass disorder.

In many past disturbances - think of riots in the 1980s and the 2001 disorder in northern English towns - the target has been the police or other groups, typically leading to lots of convictions for violence-related crimes.

This time around, many of those out on the streets were out shopping with a crowbar. While there was still some very serious violence, the charges so far broadly reflect what we all watched live on TV.

WHAT SENTENCES DID THEY GET?

Only 315 of 1,715 defendants have so far been sentenced because magistrates have been sending so many cases to the crown courts for longer jail terms.

The average sentence for violent disorder has been 10.4 months compared with 5.3 last year. The average for theft has been almost three times longer at just over seven months.

During 2010, just under a quarter of all burglaries dealt with at magistrates' courts in England and Wales led to an immediate custodial sentence - a percentage that has more doubled for rioters.

So more of the offenders are being locked up - and they are being locked up for longer, with the average sentence dished out by magistrates twice the length for similar offences last year.

The courts are not treating defendants as ordinary burglars - they are taking into account the aggravating circumstances of the riots. If you want to understand more about how these decisions are being taken, Manchester's top judges issued a very important judgement explaining why they need to sentence rioters and looters for longer.

PREVIOUS CONVICTIONS

The statisticians say that 45% of juveniles who have appeared have had no recorded criminal history. We've also found out that 73% of all of those brought before the courts have criminal histories. Each defendant with a criminal record has committed an average of 15 offences. Roughly a quarter of them have committed 10 or more offences and about 15% had between six and 10 crimes on their record. This is why Justice Secretary Ken Clarke says the figures vindicate his analysis that the offenders are a product of a penal system that has failed to turn them around.

All these previous crimes total 16,598 offences. Just under a quarter were for theft-related offences, but almost 40% were for less serious summary and breach offences.

On one level, this could suggest many looters were not serious criminals, but, given the younger profile of those involved, it could also mean the courts are dealing with lots of people whose criminal careers had only just begun.

The government's statisticians are drilling further into this data - including an attempt to establish the socio-economic background of offenders. The search for answers is still on.