There are more than a million CCTV cameras in London, and it’s time for them to start paying off. The recent riots have left local police and Scotland Yard with untold hours of video footage of looters and rioters. Advanced facial recognition software that was originally planned for the 2012 Olympics is now being applied to filter through the colossal heaps of video evidence in hopes of pairing criminals with their identities. While hundreds of people have already been arrested for their actions during the riots, it’s unclear how many, if any, will be prosectured based on CCTV camera and facial recognition evidence. Amateur attempts to use commercially available face scanning software have failed despite fervent hope from the public. While the technology has grown more powerful, and more useful in controlled situations, the quality of images from CCTV cameras may be insufficient to convict many of those involved in the looting. Law enforcement enthusiasm for facial recognition is strong, but the chances of face scanning providing immediate help in the aftermath of the London riots seems slim.
Operation Withern at the Metropolitan (London) Police is an ongoing attempt to gain valuable information about those involved in the London riots. They’ve released photographs to the general public in the hopes that witnesses will come forward to identify suspects. Facial recognition may also be able to link some of these suspects with images available on Facebook and other social media sites. Despite hours and hours of CCTV camera footage associated with the riots, however, Operation Withern has published less than 200 images of persons of interest. Where are all the other pictures of suspects?
Well, CCTV footage taken during the recent riots is often quite poor. To demonstrate, here are two typical clips that have been made widely available to the public. The first shows a group of looters breaking into a T-Mobile store, stealing some products and destroying many others. Our second clip was released by the London Police. It shows a group of police officers chasing a band of rioters only to be struck by a fleeing car. Do your best to try and discern any faces in either clip:
As we mentioned two years ago when reviewing the UK’s massive investment in CCTV cameras, the video from these devices is rarely of sufficient quality to actually convict someone. Many are located high above streets, positioned to show the backs and bodies of those below much more than their faces. In those rare instances when faces are clearly seen, the resolution of the picture may not allow police officers to reliably identify perpetrators no matter what facial recognition technology they use. It’s important to remember that in the recent history of London CCTV, there was an average of only 1 crime solved per 1000 cameras. Even with the massive amounts of video accumulated during the riot, CCTV cameras simply may not make much of a difference in pursuing those responsible for crimes.
But CCTV cameras are just a single part of the equation. News crews and private surveillance often captured higher quality recordings of the violence that unfolded. Here’s a clip of a BBC camera being stolen from a news team. While many faces are covered or otherwise unseen, those captured on this video would have a much higher chance of being recognized by software:
The greatest hope for identifying rioters may come from the general public. During the riots thousands of people took footage of crimes using their personal mobile devices. That footage has been shared on Facebook, and other public forums, leading to a few arrests. A vigilante group hoped to leverage commercial facial recognition software from Face.com to help them identify people from some of the many images acquired on CCTV, mobile devices, and other cameras. However, after only a few days, the vigilantes have called it quits. While Face.com works wonders on Facebook, as we’ve seen before, it simply wasn’t reliable enough to distinguish faces captured during the riot. Facial recognition technology developed for UK law enforcement should be considerably better than Face.com, though it’s yet to be seen if it will be able to quickly identify people captured by public devices.
Facial recognition has garnered the praise and interest of police everywhere. Heathrow Airport will be employing it soon, the US is toying with taking high quality facial scans after arrests, and private companies are developing the technology for even broader applications in the near future. Yet most of these applications are in controlled environments. You rarely see someone wearing a mask and running with a lit torch in an airport (if you do, it’s probably time to leave). Face scanning and recognition programs will work best when you can pass everyone through choke points. A single archway in a bus station, the entrance to a stadium – identifying people is going to be infinitely easier to do when you can ensure that everyone’s face is uncovered, aimed towards the camera, and moving at a reasonable speed.
For now I think that means efforts by Scotland Yard and the Metropolitan Police are simply going to fall far short of expectations. Some day video resolution and facial recognition technology will be so advanced that anyone can be identified whenever they pass by a camera. That day is simply not here yet.
Which I think is evident in the behavior of law enforcement in London. Several stories have emerged in the major press that London officials are using mobile phone records, and social media activity to identify rioters rather than trying to match their faces to names. Did you call someone from inside the riot? What did you say? Did you use Facebook or Twitter to encourage others to come with you to do some looting? Well then you’re screwed. Public admissions of involvement, even just that which can be inferred, may be much more damning evidence than your blurry face taken by a CCTV camera.
Which, if you’re a privacy person, should be even more threatening. Recognizing your face (or your gait, or your body outline, or your iris, etc) is intrusive, but it can be overcome with masks and costumes. The UK is talking about shutting down mobile connectivity, and social media sites, whenever they feel such resources are being used by those opposed to law enforcement. We’ve seen similar efforts by the Bay Area Rapid Transit here in San Francisco. BART turned off phone service in its stations to deter protesters. Faced with a disquieted public, law enforcement thinks of hindering resources that empower the public. Worry about facial recognition if you want, but that technology is years away from being the repressive tool people fear it to be. Social media is already here, and it may be leveraged against the public far more readily.
[image credit: Operation Withern ]