London (CNN) -- Tim Godwin, acting commissioner for the Metropolitan Police, defended the performance of London's police force in battling street gangs blamed for the violence that raged nationwide last week.
Referring to the disorder that first erupted in north London's Tottenham neighborhood about a week ago, he said: "The sequence of events was completely unprecedented in the history of London."
At one point, there were problems in 22 of London's 32 boroughs, he said.
Godwin added it was "a little unfair" for people to criticize the police for not foreseeing that what had started as a peaceful protest would escalate into full-scale riots.
"We take the criticism ... we have to make things better. But this was an unprecedented situation," he said.
British Prime Minister David Cameron has angered some senior police officers by saying he thought that initially there were "simply far too few police deployed onto the streets" in London, and that "the tactics they were using weren't working."
"Police chiefs have been frank with me about why this happened," Cameron said last week. "Initially, the police treated the situation too much as a public order issue rather than essentially one of crime."
Godwin pushed back against the idea that the return of Cameron and Home Secretary Theresa May from vacation had made a big difference to the police response to the unrest.
"They don't take operational decisions," he said. "We are the ones who take them and we are accountable for them."
But he said that politicians had played a role in coordinating the broader response, having summoned the government's Cobra emergency committee, which helped police to deal more effectively with government agencies and local authorities.
In an effort to better control street gangs, the British government has enlisted the help of a former New York and Los Angeles police chief.
Bill Bratton, who had private talks with Prime Minister Cameron on Friday, said there are lessons from the United States that were relevant to the situation in England.
"The specific responsibility that the prime minster has asked me to look at and help and advise on is the issue of gang crime," he told CNN's Jon Mann.
"In Los Angeles for seven years, where I was chief of police, we had great success combating it, reducing it, controlling it and it's that success that I think the prime minister is hoping might help to inform their current discussions about that issue," he said.
Large numbers of police were expected to be on the streets over the weekend following widespread rioting and looting in London and other cities, including Birmingham and Manchester, at the start of last week. Five deaths are believed to be linked to the unrest.
Police have arrested more than 2,200 people around the country, many of whom have already appeared before magistrates. Hearings are being held round-the-clock in some courts to deal with the large numbers charged.
Some 500 detectives are working on finding those responsible for looting and rioting, Godwin said, making it one of the largest investigations by the force in years.
As many as 3,000 people could pass through the courts if all those suspected of involvement are tracked down, he added.
The violence first broke out about a week ago after a protest over the death of a local man, Mark Duggan. He was shot after a police unit that deals with gun crime stopped a cab carrying the 29-year-old father of four.
Riots and looting spread across London and other cities, at a huge cost to local businesses and communities.
London's Metropolitan Police said Saturday they had charged a man with handling stolen goods after recovering electrical products worth £40,000 ($65,000) in Tottenham.
Street gangs are "at the heart of all the violence," Cameron told an emergency Parliament session Thursday, citing evidence of their ties to police attacks and looting.
Cameron said he had asked senior government ministers to work "on a cross-government program of action to deal with this gang culture" to report back to Parliament in October.
"I also believe we should be looking beyond our shores to learn the lessons from others who have faced similar problems," he said. "That is why I will be discussing how we can go further in getting to grips with gangs with people like Bill Bratton."
Cameron's Downing Street office said he had spoken to Bratton Friday after the former police chief agreed to take part in a series of meetings on tackling gangs in the fall.
"Bill Bratton, who has long-standing links with British policing, will be providing this advice in a personal capacity and on an unpaid basis," a Downing Street statement said.
Bratton, who since 2009 has worked for private security consultancy Altegrity and its subsidiary Kroll, is seen as having taken bold steps to cut crime rates in New York and Los Angeles.
"There are many lessons from these experiences that I believe are relevant to the current situation in England," he said in a statement on Kroll's website.
Bratton said he believed the British government could overcome the problem, adding: "I support their resolve to seize upon this difficult situation as an opportunity to address the issues of gangs and gang violence and the resulting fear and disorder head-on."
While there have been sporadic incidents of disorder, London has been calm since Tuesday morning and other cities since early Wednesday.
About 16,000 officers -- many more than usual -- are expected to remain on London's streets through the weekend.
In Birmingham, where three young men were killed in a hit-and-run this week thought to be connected to the unrest, community groups are planning a "peace rally" Sunday, West Midlands Police said.
The uncle of two of the men killed, Abdullah Khan, told reporters in Birmingham on Saturday that the loss of Shazad Ali and Abdul Musavir had "left our entire family in shock and devastation."
He went on: "All they wanted to do was to protect their business and other businesses within the community. I remember talking to Shazad a few days before this tragic incident and he was excited and was looking forward to the birth of his first child in a few months' time. But that was not meant to be.
"A father will never hold his child, a child will never be held by his father, a wife without a husband, parents who have lost two sons. Words can never express what we are going through at this moment."
Khan said the family did not want anyone else to suffer in the same way and appealed for witnesses to come forward.
"All we want now is justice for our family. This was not ... about race, this was not religion. This was about a pure criminal act."
CNN's Laura Smith-Spark, Claudia Rebaza and Bharati Naik contributed to this report.