LONDON — Facial-recognition technology is getting a workout in the wake of Britain’s riots, a senior police chief said Thursday, with officers feeding photographs of suspects through Scotland Yard’s newly updated face-matching program.
Chief Constable Andy Trotter of the British Transport Police said the software was being used to help find those suspected of being involved in the worst unrest London has seen in a generation.
He cautioned that facial recognition makes up only a fraction of the police-force efforts, saying tips have mostly come from traditional sources, such as still images captured from closed-circuit cameras, pictures gathered by officers, footage shot by police helicopters or images snapped by members of the public. One department was driving around a large video screen displaying images of suspects.
“There’s a mass of evidence out there,” Trotter said in a telephone interview. “The public are so enraged that people who wouldn’t normally come forward are helping us, especially when they see their neighbors are coming back with brand-new TVs.”
Prime Minister David Cameron, meanwhile, acknowledged Thursday that police were overwhelmed by the rioting that began last Saturday in London and spread across the country over five days. Mobs looted stores, set buildings aflame and attacked police officers and other people, a chaotic and humbling scene for a city a year away from hosting the Olympic Games.
At an emergency session of Parliament summoned to discuss the riots, Cameron said authorities would consider curfews, constraining smartphones and social-networking sites, and filling some police functions with soldiers to keep more officers on the street.
He also said he would consult a former New York City police commissioner, William Bratton, who presided over a record drop in crime there in the 1990s, on ways to counter criminal gangs. Cameron said there was “some evidence” that criminal gangs had been behind the wave of arson and looting. Bratton also headed police forces in Boston and Los Angeles, and is now chairman of a New York-based security company, Kroll Associates, that advises police forces around the world.
Cameron said police were authorized to use plastic-coated bullets against rioters and that plans were in place to deploy water cannons when appropriate.
“Nothing should be off the table,” he said. “Every contingency is being looked at.”
Officials under fire
The police said more than 1,200 people had been arrested, most in London, since the frenzy of violence that began Saturday. The situation eased only after thousands of police reinforcements flooded the streets of London and other major cities.
The violence prompted widespread criticism of police for an ineffective initial response and deeper failures, including corruption and collusion exposed by the broadening phone-hacking scandal.
Few members of British society were spared: Politicians came under fire for failing to break off summer vacations immediately to confront events; and they in turn denounced a society that has allowed hooliganism, public drunkenness and gang culture, including thuggish behavior toward the weak and disabled.
For the first time, Cameron said police commanders had acknowledged they had misjudged the situation at first and deployed too few officers.
“Initially the police treated the situation too much as a public order issue, rather than essentially one of crime,” he told the lawmakers, blaming a wide social breakdown for the violence.
“This is not about poverty, it’s about culture,” he said, “a culture that glorifies violence, shows disrespect to authority, and says everything about rights but nothing about responsibilities.”
Facial recognition
A spokesman for London’s Metropolitan Police, widely known as Scotland Yard, confirmed that facial-recognition technology was at authorities’ disposal, although he gave few details.
The spokesman, who spoke on condition of anonymity, said that generally, the technology would be used only to help identify those suspected of serious crimes, such as assault, and that in most cases disseminating photographs to the general public remains a cheaper and more effective way of finding suspects.
The facial-recognition technology used by police treats the human face like a grid, measuring the distance between a person’s nose, eyes, lips and other features. It has recently been upgraded, according to an article published last year in Scotland Yard’s bimonthly magazine, “The Job.”
The March 2010 article said the new program has been shown to work far better than older versions of the technology, with one expert quoted as saying it had shown promise in identifying people from high-quality, face-on shots taken off surveillance photographs, mobile phones, passports or the Internet.
A law-enforcement official said that to use the technology “you have to have a good picture of a suspect and it is only useful if you have something to match it against. In other words, the suspect already has to have a previous criminal record.”
He also spoke on condition of anonymity.
In another effort to identify suspects, police have released two dozen photos and videos to the picture-sharing website Flickr, where they’ve gathered more than 400,000 hits. Some of those photographs have also been published by Britain’s tabloid press. The Sun recently plastered them across its front page, along with a headline urging readers to report looters to the police.
The photographs on Flickr are mainly grainy images pulled from cameras, which may not be of much use to face-matching software. But detectives were scanning the Web for pictures of high-quality photographs of rioters’ faces, according to photojournalist Guilherme Zauith, who witnessed some of the disturbances in London and later posted images of clashes to the Internet.
Zauith said he was recently contacted by a London detective “saying that they saw my photos online and if I could send it to them to help to identify the people.”
Zauith said he gave the photos to the detective.
The West Midlands police were trying another approach: driving a van equipped with a large screen displaying 50 images of suspects through Birmingham.
Police said the “Digi-Van” will stop at key locations around the city to give shoppers and commuters a good look at the photographs in hopes they can help identify suspects.
Facial-recognition technology is widely employed by free-to-use websites such as Facebook and Google’s Picasa photo-sharing program.
Such programs have been of increasing interest to authorities. A person with the Olympic planning committee, speaking on condition of anonymity, said facial-recognition software was being considered for use as a security measure during the Olympic Games.