US 'supercop' Bill Bratton says riot arrests not only answer
Communities cannot "arrest their way out" of gang crime, the prime minister's new crime adviser, US "supercop" Bill Bratton, has warned.
The former New York police chief meets David Cameron next month to discuss violence in English cities and says the issue is for society as a whole.
But some police described Mr Bratton's appointment as a "slap in the face".
Ian Hanson of the Greater Manchester Police Federation said Britain did not need someone from "5,000 miles away".
"There is anger, there is disappointment, a degree of incredulity as well," Mr Hanson told ITV News in excerpts to be aired on Saturday.
"What we've witnessed this week has been British policing at its absolute best.
"The police leadership has also stepped forward in support of their officers and the service and now to be given this slap in the face by the prime minister and told that he wants to bring in Bill Bratton to cure all policing ills."
Extra police numbers will be maintained on city streets through the weekend.
But the Chancellor, George Osborne, dismissed calls to reverse cuts to police budgets. He welcomed the advice from Mr Bratton, saying that he would help tackle the "deep-seated social problems" behind the riots.
Mr Bratton, who is also credited with restoring law and order in Los Angeles after the riots there in 1992, told US broadcaster ABC: "You can't arrest your way out of the problem.
"Arrest is certainly appropriate for the most violent, the incorrigible, but so much of it can be addressed in other ways and it's not just a police issue, it is in fact a societal issue."
Bill Bratton is not a complete outsider to British policing. He's been a consultant advising different forces.
His initial success in New York relied on big increases in resources - recruiting 5,000 new better trained officers. They needed a local crime tax to pay for that. In London, flooding the streets has only been possible as a temporary measure.
In Los Angeles he worked on smaller budgets, specifically tackling gangs, using Big Society ideas of local areas taking responsibility for fighting crime in their neighbourhoods.
He's talked of using escalating force - rubber bullets, water cannon, tasers - something David Cameron has also been talking about.
There are people in this country saying "we invented neighbourhood policing". It's a bit of a slap in the face for some of Britain's top police.
Accepting that the necessary changes would not be easy, he added: "Part of what the government is going to do is to take a look at what worked and what didn't work during the course of the last week."
He said he would share his experience of combining tough tactics with community outreach to reduce US gang violence in a bid to prevent recurrences of the violence in the UK.'Different culture'
Downing Street said Mr Bratton would not be a long-term, paid consultant and would not be formally appointed to any UK police force.
However, Metropolitan Police Federation chairman John Tully said he did not think American advice would help.
"Although he has a glittering record across in the States, it's a different style of policing. The gang culture's different," he said.
Former Scotland Yard Commander John O'Connor was also sceptical.
"The Americans didn't cure the social problems in New York. What they did is they locked people up. That's how zero tolerance works. We haven't got the heart for that over here," he said.