The claim

“The read-across from America to the UK is not perhaps as obvious as some people think… His (Bill Bratton’s) particular success in tackling crime in New York was very much due to a huge ramp up in numbers from about 30,000 to 42,000 officers in New York”

Boris Johnson, Mayor of London, The New York Times, 14 August 2011

The background

Boris Johnson doesn’t want America’s Supercop swooping down on the Met Police with his hard-line “zero tolerance” policies.

And neither does Sir Hugh Orde, President of the Association of Chief Police Officers, who said America’s heavy-handed tactics are employed to tackle levels of violence that are “so fundamentally different from here”.

By way of explanation, Mr Johnson cherry picked the murder rate in New York City – which is four times higher than London’s.

But murder aside, how does crime in the two cities compare? And is the NYPD better equipped to deal with it, than the Met? FactCheck does some sleuthing.

The analysis

Former New York Mayor Rudy Giuliani cut crime in half during his term, which ended in December 2001. It’s a well documented fact that violent crime fell 56 per cent in New York under Giuliani; while police numbers rose to around 40,000 in 2000.

But FactCheck‘s counterpart in the US, the well-respected has long proved this rise in police numbers a slight of hand.

Mr Giuliani claimed he’d put police numbers up by 12,000 between 1994 and mid-2000. But actually, 7,100 of them were already working as housing or transit police and were simply recounted under the merger of departments.

The real increase was 3,360 over the six year period, and crucially the cost of hiring these officers was partially covered by the Federal Government under President Bill Clinton’s 1994 crime bill.

In the years since, the New York Police Department (NYPD) has shrunk to a force of 34,500 today – not much larger than the Met’s 32,000. While the Met has done the opposite – dipping from a force of almost 28,000 in 1994 to just under 25,500 in 2000, before climbing again.

The economic crisis has hit the NYPD too, with the force facing budget cuts of $19m (£11.6m) and announcing plans to cut 349 civilian jobs this year.

While it’s not cutting frontline jobs, the NYPD does admit the move “may have a negative impact on the Department’s uniform deployment strength to the extent that it becomes necessary to assign active duty uniforms to clerical, non-law enforcement functions”.

The Met is dealing with much heftier cuts – with the Government scaling back its funding by £109m. But at £3.6bn, the Met’s budget eclipses the NYPD’s $4.5bn (£2.7bn) budget for 2011.

As it stands today, the NYPD has a few thousand more officers than the Met, policing a population of a few hundred thousand more than London.

Yet the rate of violent crime rate is less than half that of London’s

Some argue that New York City’s crime rate was already on the wane before Giuliani – in Freakonomics, for example, Steven Levitt and Stephen Dubner put it down to the rise in abortion rates in the 1970s.

Either way, back in 1998 the UK’s own Police Federation acknowledged the zero tolerance policy for “causing dramatic falls in crime in New York City in the mid 1990s under the city’s then Police Commissioner, Bill Bratton”

What is zero tolerance? It’s a strategy devised in the 1983 by two American academics, George Kelling and James Wilson.

Under their “broken windows theory”, minor criminality leads people to feel unsafe and ultimately leads to more serious crimes. Or as David Cameron put it: “If you leave the bus shelter with graffiti all over it, it gets trashed even further.”

But is it right for Britain? The debate rages on, but it has been proven to work – most famously by Ray Mallon who as Detective Superintendant of Middlesbrough CID in 1996 promised to quit if he didn’t manage to cut crime by 20 per cent in 18 months. He brushed off his zero tolerance approach as “no more than good, basic policing”.

In 1997, he said: “It is about the police intervening on the street wherever they see crime or anti-social behaviour. It doesn’t mean arresting lots more people for so called ‘minor’ offences but it does mean that turning a blind eye is not an option”.

The verdict

Mr Johnson would have us believe that pitting London against New York is as fruitless as comparing The Bill to CSI:NY – flagging the high murder rate as proof of America’s gun-toting badland.

But murder aside, why does London have a vastly higher rate of rape than New York? Or of violent crime?

Mr Johnson says it comes down to police numbers. “In the end there’s going to have to be an argument about money. The case I make to Government and I’m going to continue to make is that numbers matter. People need to see police out there on the streets,” he insists.

As we’ve shown, New York has a similar number of officers to London, policing a similar number of people. Granted, Greater London is double the size of New York City’s 301 square miles, but the Met Police’s budget is almost a billion more than the NYPD’s.

Comparing the two cities then, surely isn’t completely outlandish – it can’t just be police numbers that curb crime, it must be tactics too.

By Emma Thelwell