BBC News | June 18, 2008

Sir Ian Blair, the Metropolitan Police Commissioner, believes there is "almost no public faith" in crime figures. 

At the second Colin Cramphorn memorial lecture, he said the way crimes were categorised had been changed "so frequently they are bewildering".

He said British authorities should adopt a more straightforward approach.

Sir Ian also said the media and politicians had weakened confidence, adding that there was more faith in simpler statistics in New York, US.

The Met chief said: "Few question the crime figures in New York. Residents largely accept that their city is safer than it was.

"And that is because New York has not fiddled about with how they collect crime statistics in the way the UK has."

Crime decline

He argued that many people would be surprised at how many crimes were recorded. By way of example he said that until recently gun-enabled crime had included attacks with CS gas.

And he mocked a definition of knife crime provided for police which included an exhaustive list of weapons ranging from machetes, axes and crossbows to darts and needles.

Sir Ian, whose speech was delivered at the Policy Exchange, called for crime counting rules to be revised to make figures simpler and more credible.

The police commissioner also stressed that recent crime figures showed almost every category of crime was in decline in London.

Political accountability

Sir Ian also rejected calls by London Mayor Boris Johnson for the Home Office to examine whether the Met should keep national responsibilities such as counter-terrorism.

The mayor has said that if such responsibilities were hived off, Londoners would be able to have a commissioner who is directly politically accountable.

But Sir Ian said he feared that the creation of separate units could lead to unhelpful inter-force rivalries like those he said existed in the US.

"Losing Met primacy in this field would diminish UK counter-terrorism capability, as well as risking bringing in its wake the disadvantages I have described in some parts of the US," he said.