In 2012, a ruling by Britain's High Court found that keeping the mugshots of innocent people in police databases was unlawful. But almost six years later, the country's Home Office has defended the continued retention of such images, saying, basically, the problem is too expensive to fix.
According to a report presented to Parliament, at least 19 million facial images are in contained in the UK's Police National Database (PND), which is used to power facial recognition technology. Hundreds of thousands of these photos are believed to be of people who were never charged with or convicted of a crime. And as not every police force contributes photos to the PND, the total number of such images in the country is thought to be even higher.
After reviewing the matter, the Home Office said last year that mugshots of innocent people should be deleted by request. When pressed on why such images haven't been automatically deleted from police databases, the Home Office recently asserted that doing so would "need to be done manually," making the cost "difficult to justify."
As explained in a letter by Baroness Williams of Trafford, the Home Office minister responsible for biometrics, mugshots are stored in local police databases, then uploaded to the larger PND. While deleting the image from local storage removes it from the PND, the reverse is not true. To coordinate deleting mugshots across the UK, "it would be necessary to upgrade all 43 local systems and the PND," the letter asserts.
"Thus any weeding exercise will have significant costs and be difficult to justify," Williams writes.
Norman Lamb, chair of the House of Commons' Science and Technology Committee, was less than satisfied with this explanation.
"Innocent people should rightly expect that images gathered of them in relation to a crime will be removed if they are not convicted," said Lamb in response. "This is increasingly important as police forces step up the use of facial recognition at high profile events - including the Notting Hill Carnival for the past two years."
Lamb said his committee will continue to push for automation, noting that, without it, many innocent people will have their faces retained in police databases - sometimes without even realising it.
Across the globe, face recognition is transforming law enforcement. In the US, it's being used in airports as passengers board flights, in arenas when people attend concerts, and even in some schools to deter school shooters. Police can use the technology to quickly find suspects, but civil liberties experts are wary of normalizing face recognition, which both identifies people in public places and matches them against criminal databases. Simply walking to the corner shouldn't involve a police search. People are usually willing to bend this belief when it comes to convicted criminals, but, until these "upgrades" happen, everyone who has made contact with police is potentially caught in the dragnet in Britain.