The release of new Home Office statistics
this morning has pushed the issue of crime to the top of the news agenda. Nowhere is this truer than in London, which was shown to have the highest incidence of crime in the country.
It was therefore unsurprising that the Mayor of London Boris Johnson faced a grilling on the subject during Mayor's Question Time
BNP member of the Greater London Authority (GLA) Richard Barnbroke took the opportunity to accuse the Mayor's office of downplaying knife crime in London.
He claimed: "Last year there were 13 cases of minors murdered by knife crime, this year, at July, the figure is 14."
Responding, Mr Johnson argued that "youth crime is down substantially in the last couple of years...and we've taken 9,500 knives off the streets."
So who paints the more accurate picture of crime in the capital?
The Metropolitan Police launched 'Operation Blunt 2', an initiative aimed at reducing knife crime, in May 2008 in tandem with the newly-elected Mayor. According
to City Hall figures 9,500 knives have been seized since then.
However there has been some debate about how useful these numbers are for gauging the success of the Mayor's policies.
As the name suggests, 'Operation Blunt 2' was preceded by a crackdown on knife crime begun under the previous Mayor, Ken Livingstone.
Roger Grimshaw, of the Centre for Crime and Justice Studies, told Full Fact that Mr Johnson's use of this statistic needed greater context.
"Knife crime in London has been falling since 2004, and the original Operation Blunt, begun by Mr Johnson's predecessor as Mayor, is arguably the most important factor in instituting this trend," he said.
Furthermore, the British Crime Survey uses data gathered from victim surveys and incidents reported to the police to model the impact of crime. It therefore only records data pertaining to the victims of crime, and cannot be used to determine the ages of the offenders committing crime.
Full Fact contacted City Hall to enquire after the source of the Mayor's claims, and was directed to data held by the Metropolitan Police. We have yet to receive the figures we requested from the Met.
However Youth Offender Team data
published by the Ministry of Justice does seem to confirm Mr Johnson's assertion that youth crime has fallen during his tenure.
For the financial year 2007/08 there were 866,038 cases handled by Youth Offender Teams (YOTs), with 848,229 cases seen during Mr Johnson's first year in office. Data for the year 2009/10 has not yet been published.
Again however, this decline is less impressive than at first it may appear. Whilst Mr Johnson can legitimately claim to have presided over a fall of 2.06 per cent during his tenure as Mayor, this compares less favourably with drops of 6.34 per cent and 6.27 per cent seen in the last two years of the previous administration.
The YOT figures also give some weight to Mr Barnbroke's observations regarding a rise in the number of high-profile knife crime cases involving minors.
Cases of violence against the person recorded by YOTs actually rose during Mr Johnson's first year of office, from 172,979 in 2007/08 to 174,774 in 2008/09. This followed three consecutive drops in youth violent crime in London which began in 2004, the year in which the original Operation Blunt was launched.
This is particularly damaging for the Mayor, as violent crime amongst youths actually fell between 2007/08 and 2008/09 nationwide. There was also a 5.02 per cent fall in all youth crime nationally between these years, larger than the 2.06 per cent drop achieved by Mr Johnson in London.
When discussing the impact of Mayoral policy on London's crime statistics, it is therefore paramount that a wider context is not lost. Boris Johnson can point to a fall in youth crime over his first year in office, but the drop compares less favourably to historic and national benchmarks.
Likewise, the numbers of knives removed from the capital's streets cited by Mr Johnson do not seem to have precipitated a fall in youth violent crime, so Mr Barnbroke is justified in querying the Mayor's success in this sphere.
As a Youth Justice Board spokesperson told Full Fact: "There has been an encouraging downward trend in youth crime stretching back far earlier than 2008, and this has by no means been confined to London."