The claim
“Violent crime almost doubled under the last government.”
David Cameron, prime minister’s questions, 7 July 2010

Cathy Newman checks it out
Beware politicians peddling crime statistics. Many a minister has come a cropper by making misleading claims about law and order. So when David Cameron asserted at prime minister’s questions today that gun crime and violent crime went “through the roof” under the last government, FactCheck decided to take a look.

Over to the team for the analysis
One series of stats seems – at a glance – to show violent crime has increased sharply under Labour. This is police-recorded crime – the number of violent incidents reported to, and noted down by, the police.

But that doesn’t conclusively prove violent crime actually increased on the ground. The figures are affected by whether people choose to report that they’ve been attacked, and how that’s then recorded by the police.

The other main source of crime statistics, the British Crime Survey (BCS), takes a difference approach. It asks thousands of people about their experiences of crime in the past year, regardless of whether or not they went to the police. It’s not perfect – it doesn’t include under-16s, students in halls of residence or people in care homes, and doesn’t cover all types of offences. But it is widely reckoned to be the best way of measuring trends in crime over time, because it isn’t affected by changes in crime policy or counting rules in the way police-recorded crime might be.

And the BCS shows the opposite picture to Cameron’s claim – that violent crime in fact went down by 41 per cent under Labour. According to the latest Home Office statistical bulletin, this shows that the growth in violent recorded crime “should be attributed, at least in large part, to a change in recording practice”.

The Tories have tripped up on this before.  Chris Grayling, when he was shadow home secretary, was slapped down by the statistics watchdog for claiming violent crime had gone up under Labour.  The stats authority chief wrote to him – and copied the letter to David Cameron – saying this kind of bold assertion based on recorded crime stats was “likely to mislead the public”.

But Cameron made exactly the same kind of unqualified claim today. FactCheck asked the UK Statistics Authority if it would be taking any action or wished to comment, and will update this if we get further info. The shadow home secretary, Alan Johnson, has also written to Sir Michael Scholar asking for the watchdog’s view on the PM’s comments.

The prime minister’s spokesman said: “There’s been a long-standing debate on the figures and that different people interpret them in different ways”.

Update: A Statistics Authority spokesperson later said it was “looking into the issues raised” in Alan Johnson’s letter.

Cathy Newman’s verdict
David Cameron will no doubt say that the police-recorded crime figures back him up. But the prime minister really should have learnt from Chris Grayling’s mistake. If the stats watchdog has any teeth, it’ll rebuke Cameron too – and Labour would presumably demand some kind of clarification in the Commons. So after carefully taking down the evidence, FactCheck is handing the PM a fiction rating.

Update (14 July 2010): The Statistics watchdog wrote to David Cameron today, confirming FactCheck’s verdict on the PM’s dodgy violent crime comparison. In a letter copied to No. 10, Sir Michael Scholar said he stood by a previous ruling that it was “not possible” to compare recorded crime statistics over Labour’s time in office. The longest recent period in which the stats could be compared showed violent crime rose from 845,000 offences in 2002-3 to 1,060,000 offences in 2005-6, then fell back to 903,000 in 2008-9, he said – far from the doubling Cameron claimed. Sir Michael also pointed out that the British Crime Survey, which the watchdog considers to be the most reliable measure of violent crime, had not shown an increase since the late 1990s.

Sir Michael said the Statistics Authority did not want to be drawn into political debate. ” But I hope that those who comment in parliament and elsewhere on trends in violent crime will take account of the points made in this letter,” he wrote. New crime figures are due out tomorrow – FactCheck will be watching closely for any selective spin from politicians of any party.