Newly aggressive police methods have helped to lower crime figures in New York, said Professor Ronald Clarke, who was head of research and planning at the Home Office until 1984, but he warned that they were unlikely to do much good in Britain. Worse, they could incite a backlash in neighbourhoods with large minority communities.
"There is really no comparison between New York and Britain," Prof Clarke, who is now dean of the school of criminal justice at Rutgers University in New Jersey, said in an interview. "I really doubt that developing the same sort of tactics is really going to do any good in Britain. There is a real risk of applying this in an overly heavy-handed way. I think that it could quickly run into problems in areas like south London."
Shaking off its reputation as one of the world's most dangerous cities, New York has recently boasted an astonishing decline in its crime statistics. Figures released last month by the FBI on violent crime ranked New York 138th among America's cities, on a par with Boise, Idaho. The number of car thefts last year fell to 71,000 compared with 150,000 in 1990. Most dramatically, the murder rate has virtually halved over the same period.
Lest we get carried away, it remains true that New York still suffers a murder rate that would be unacceptable to most other Western cities. (There were 1,182 murders in New York over 12 months from April 1994, compared with 174 in London, with comparable populations in the two cities). But still, something dramatic has occurred to reverse the criminal trend.
Criminologists offer a pot pourri of explanations. There has been a demographic shift, with fewer young males in the American population, the group most prone to violent crime. The turf wars between rival drug gangs that spurred much of the worst violence are considered to have stabilised. Moreover, many of the most heinous offenders now find themselves behind bars, no longer able to spray the streets with their bullets. Along with these insights is the observation that crime levels have also been falling in many other American cities, such as Houston, New Orleans and Miami.
But nowhere has the decline been as spectacular as in New York. It becomes impossible, therefore, not to give some credit to the New York police and, in particular, their recently-retired chief, William Bratton.
Mr Bratton instigated several changes in policing tactics in the city, and the apparent success of those changes has attracted the attention not just of Mr Howard, but of other US cities hoping to emulate them.
At the heart of the strategy was the espousal of a "zero-tolerance" approach, whereby New York's finest would respond to all offences instantly, no matter how minor. Even public nuisance violations, such as urinating in the streets or drinking alcohol in public, were challenged. (Hence, in the precinct houses, it became known as the "piss and beer" strategy.)
Mr Bratton, who pioneered the approach as head of New York's subway police in the late Eighties, took his cue from the "broken window" theory developed by the criminologist James Wilson, 15 years ago. It holds that tolerating small blemishes on the social landscape - broken windows, graffiti - helped to engender more serious types of transgressions, because would-be criminals got the message that no one cared. Tackle those blemishes, and crime levels will fall. Mr Bratton's blitz against turnstile-jumpers and graffiti artists on the subway helped to cut violent crime on the New York system by nearly two-thirds.
In his two-and-a-half years as New York police commissioner, Mr Bratton was blessed with the perfect political environment to pursue his aggressive policing strategy across the city. Rudolph Giuliani, a former federal prosecutor, was elected mayor in 1993 on a promise to tackle crime. A new get-tough attitude also flourished at the national level. Only last week, President Bill Clinton spoke in support of those cities, including Chicago and New Orleans, that have introduced strict curfews to keep teenagers off the streets after dark.
Nor is it hard to fathom why the Bratton doctrine, with its whiff of big-stick authoritarianism, should have found favour with Mr Howard. But Prof Clarke and others say there may be several reasons to wonder whether what has been done here can provide the Government with a "silver bullet" against crime in British cities.
Their doubts are explained when one understands how "zero tolerance" actually worked for police in New York. By hauling in every turnstile- jumper and graffiti artist and checking with their precinct headquarters, the police often found that the transgressor was guilty of more serious crimes, particularly gun possession. The threat of arrest for the slightest petty offence also discouraged criminal elements from having guns or drugs on their person. "Zero tolerance enabled them to net a lot of people and net some bigger fish," explained Prof Clarke. But despite horrors such as Dunblane, gun possession is not a problem on British streets.
Lawrence Sherman, a criminologist at the University of Maryland, is an unabashed fan of Mr Bratton, firmly believing that his tactics are directly correlated to the city's lowering crime figures.
But London, he is quick to point out, is not New York. "It was just what New York needed, but it is not what London needs," he concluded last week. "England is not New York City, especially in the realm of gun- carrying, which was always the main target of the police intervention under Bratton.
"Trying to target gun-carrying in England would be about as useful as trying to combat malaria in Iceland."
The new police tactics appear to have led to a sharp rise in civil complaints, which rose by a third in the first half of last year - three-quarters of all the complainants were black or Hispanic. But, in general, criticism has remained strikingly muted in New York. There has been no backlash, such is the gratitude of most of the residents for the opportunity to get their neighbourhoods back.
In London, by contrast, there is a far higher degree of policing by consent than in New York. Violent crime and the fear of it are far lower. The more aggressive approach welcomed by many on the streets of the Big Apple would seem alien in British cities, and might have the effect of raising tension rather than reducing it.
Prof Clarke resigned from the Home Office after making public his view that increasing the numbers of police officers on the streets would not help reduce crime, as his then minister, Sir Leon Brittan, had been contending. "I feel terribly weary when I think about these debates and how they always focus on the simplistic solutions that every criminologist knows will not work," he said last week.