Politicians and Protesters Assail British Police

Britain’s latest convulsion of rioting and looting began with a protest against the police handling of a killing in north London, but it soon turned into something much bigger — a challenge to state authority that shook the political elite, and, for the police itself, one more bleak entry in a catalog of crisis and condemnation.

In Parliament, recalled from recess on Thursday, a chorus of lawmakers denounced the police response to the riots as incompetent. One said that officers were instructed to “stand and observe looting.” Prime Minister David Cameron said he would look to an American expert for help — William J. Bratton, who helped reduce crime levels in New York City in the 1990s.

Ever since the murder of a black teenager in 1993, the British police — who once held an affectionate place in life here — have been embroiled in contentious episodes ranging from the mistaken shooting by plainclothes officers of a Brazilian electrician, Jean Charles de Menezes, in the aftermath of the July 7 London subway and bus bombings in 2005, to the death of a newspaper vendor manhandled by police at a protest against globalization in 2009.

Only weeks ago, London’s Metropolitan Police, widely known as Scotland Yard, faced public questioning over a failure to fully investigate a phone hacking scandal that led to the resignation of its two most senior officers.

Now, with images of officers standing by as parts of London burned, seemingly outwitted and outmaneuvered by masked and hooded marauders, the police are condemned by some rioters as a cause of their rage, and are the butt of public outrage at the failure to prevent the violence from spreading.

“There were simply far too few police deployed on to our streets,” Mr. Cameron said of the initial days of the riots this week, “and the tactics they were using weren’t working.”

As Theresa May, the cabinet minister responsible for policing, told Parliament, “Policing by consent is the British way, but the police only retain the confidence of the wider community if they are seen to take clear and robust action in the face of open criminality.” She added later that often “officers are damned if they do and damned if they don’t,” in cracking down on protests and riots.

The broader question, though, is this: How did a national institution once held in esteem, or at least respect, by many Britons — “bobbies on the beat” to an earlier generation — become a force of such contention, even as, in recent years, it has taken credit for shielding the country from an array of terrorist plots?

With their tall, rounded helmets, British police officers have traditionally avoided shows of strength in favor of community policing. Most British officers still do not carry guns.

Yet, in recent years the force, overwhelmingly white, has faced accusations of racism, brutality and incompetence that it has struggled to shake off.

The story of the change in their place is one of incremental missteps as the nature of society itself has changed. Britain has become more diverse and complex in an era when the smash-and-grab crime of earlier decades has been replaced by far more sophisticated law-breaking. And at the same time, the point of contact between the police and the people has been increasingly shaded with questions of race and resentment.

During the latest riots, the most violent in memory, officers were overrun by nimble, well-connected rioters using bicycles, mopeds, smartphones and social networking to organize violence and theft across the capital. At several of the riots, young men could be seen whizzing away from slowly massing riot police officers, only to gather elsewhere.

Across London, as people surveyed the wreckage of their homes and businesses, many complained that the police had done too little. On Wednesday Mr. Cameron announced new plans that would allow the British police to deploy water cannons and plastic bullets against any new violence. The Associated Press reported that facial recognition software would be used to identify looters and rioters captured on CCTV and other cameras. And Mr. Cameron added Thursday that he wanted to discuss going “further in getting to grips with gangs with people like Bill Bratton, former commissioner of police in New York and Los Angeles.”