More than 70% of the 1,715 brought to court had previous convictions or cautions, but many youngsters had clean records The riots that swept through English cities last month involved a hardcore of repeat offenders but also drew in others, particularly youngsters, who had no criminal history at all, the first official analysis has found. Detailed Ministry of Justice scrutiny of the 1,715 defendants on riot-related charges who have faced the courts also show that magistrates and judges have taken an even tougher approach to sentencing than previously thought. London courts are dealing with convicted rioters more harshly than those in other cities, according to the analysis. The figures show that 90% of those before the courts were male, and most were young ? with 21% aged 10-17 and 31% aged 18-20. The analysis confirms the claims by the justice secretary, Kenneth Clarke, that "existing criminals were on the rampage" with its data showing that 73% of those before the courts had been previously cautioned or convicted. Clarke said the figures lent weight to his intention to bring in radical prison reforms to prevent this "hardcore of repeat offenders" simply going round and round the system. The "hardcore" claim is bolstered by figures showing 25% of those charged had been convicted of more than 10 previous offences and had previously served a jail sentence. About 10% of those brought to court were either already serving a community order or had been released from prison on licence. But beyond that the evidence is more complicated. While it is true that 77% of adult riot suspects had a criminal history, this falls to 55% among juveniles ? indicating that many more of those defendants had been drawn into the criminal justice system for the first time. The former Labour lord chancellor, Lord Falconer, has also questioned whether the previous convictions were simply cautions for shoplifting or lengthy prison sentences for serious violent attacks. Here the figures are less conclusive. The 1,100 or so riot suspects with a previous criminal record are said to have committed a total of 16,598 previous offences between them ? an average of 15 each. But the detailed breakdown shows that 39% of these are described as "summary and breach offences", ie more minor crime, and 9.6% of the total were dealt with by a caution. The 61% of previous convictions for more serious indictable crimes include mainly theft and handling stolen goods and drug offences. The MoJ analysis also shows that the courts have actually been handing out tougher sentences than previously thought. So far 315 people have been sentenced, of whom 176 were given an immediate jail sentence with an average length of 11.1 months. For the magistrates this represents an imprisonment rate of 43% for riot cases compared with just 12% of cases for similar offences in 2010. In theft cases, the imprisonment rate has risen to 67% ? compared with 2%. At crown courts, which have so far dealt with 79 cases, the immediate custody rate has risen to 89% compared with 33% normally. Sentence length is also longer ? up to two or three times longer than the normal term for similar offences. Theft cases have attracted an average sentence of 7.1 months compared with the normal "going rate" of 2.4 months; burglary 14.1 months (normally 8.8 months); and violent disorder 10.4 months (normally 5.3 months). The figures also underline how much the London disturbances dominated the riots. So far 1,149 of the 1,715 riot cases relate to London. Greater Manchester has 198 cases, West Midlands 139, Merseyside 69, Nottingham 65 and the rest of England and Wales 95. On Wednesday the Guardian revealed a memo had been circulated to London's courts telling magistrates to ignore sentencing guidelines when dealing with rioters. London magistrates appear to have referred more cases to crown court than other regions and kept more prisoners on remand: 58% of those passing through London courts were remanded, compared with 36% in Manchester. The effect is even more pronounced for juveniles, with 85 of the 183 youths passing through London courts remanded in custody, compared with just two of Nottingham's 17 youth cases and one of 14 in Manchester. Early indications from the Guardian's data also suggest sentencing varies between the cities. One 17-year-old, who admitted stealing clothes and sweets from Poundland in Peckham received an 8-month sentence, four months of which will be served in detention. By contrast, a 16-year-old who admitted looting Swarovski's jewellers in Manchester received a non-custodial sentence. ? This article was amended on 21 September 2011. The original said a 17-year-old, who admitted stealing clothes and sweets, received a 12-month sentence, six months of which will be served in detention. This has been corrected. UK riots Crime London Youth justice Sentencing UK criminal justice Young people Prisons and probation Kenneth Clarke Alan Travis James Ball Fiona Bawdon guardian.co.uk © 2011 Guardian News and Media Limited or its affiliated companies. All rights reserved. | Use of this content is subject to our Terms & Conditions | More Feeds