Met police deploy facial recognition in Westminster

A necessary and proportionate deployment?

Before it can deploy facial recognition technology, the MPS must meet a number of requirements related to necessity, proportionality and legality.

For example, the MPS’s legal mandate document – which sets out the complex patchwork of legislation the force claims allows it to deploy the technology – says the “authorising officers need to decide the use of LFR is necessary and not just desirable to enable the MPS to achieve its legitimate aim”.

In response to questions about how the force decided the Westminster deployments were necessary, the MPS said “the deployment was authorised on the basis of an intelligence case and operational necessity to deploy, in line with the Met’s LFR Documents.”

In terms of the basis on which the deployment was deemed proportionate, it added “The proportionality of this deployment was assessed giving due regard to the intelligence case and operational necessity to deploy, whilst weighing up the impact on those added to the watchlist and those who could be expected to pass the LFR system.”

The MPS’s Data Protection Impact Assessment (DPIA) also says that “all images submitted for inclusion on a watchlist must be lawfully held by the MPS”.

In 2012, a High Court ruling found the retention of custody images – which are used as the primary source of watchlists – by the Metropolitan Police to be unlawful, with unconvicted people’s information being kept in the same way as those who were ultimately convicted. It also deemed the minimum six-year retention period to be not proportionate.

Addressing the Parliamentary Science and Technology Committee on 19 March 2019, then-biometrics commissioner Paul Wiles said there was “very poor understanding” of the retention period surrounding custody images across police forces in England and Wales.

He further noted while both convicted and unconvicted people could apply to have their images removed, with the presumption being that the police would do this if there was no good reason not to, there is “little evidence it was being carried out.”

“I’m not sure that the legal case [for retention] is strong enough, and I’m not sure that it would withstand a further court challenge,” he said.

Asked how it had resolved this issue of lawful retention, and whether it could guarantee every image in the 28 January watchlists were held lawfully, the MPS cited section 64A of the Police and Criminal Evidence Act 1984, which gives police the power to photograph people detained in custody and to retain that image.

It added that the custody images are also held in accordance with Management of Policing Information Authorised Police Practice (MOPI APP) guidelines.

“To comply with the MOPI APP, the MPS has simplified the Custody Image deletion process and has put in place measures to proactively facilitate custody image deletion,” said an MPS spokesperson. “Individuals can now make a formal request for their image to be deleted via a link on MPS website, or attend any MPS police station to make their request in person and the deletion decision will be made with reference to the current MOPI APP guidelines on custody images.”

Carlo told Computer Weekly that a police officer on the ground informed her there were 9,500 images on the watch list for the deployment. The MPS’ post-deployment document confirmed the watchlist contained 9,756 images.

“That’s not a targeted and specified deployment because of a pressing need – it’s a catch net,” she said.

In July 2019, a report from the Human Rights, Big Data & Technology Project based at the University of Essex Human Rights Centre – which marked the first independent review into trials of LFR technology by the Metropolitan Police – highlighted a discernible “presumption to intervene” among police officers using the technology, meaning they tended to trust the outcomes of the system and engage individuals that it said matched the watchlist in use even when they did not.

On how it has resolved this issue, the MPS said it had implemented additional training for officers involved in facial-recognition operations.

“This input is given prior to every LFR deployment to ensure officer are aware of the current systems capabilities. LFR is a tool that is used to help achieve the wider objectives of the policing operation, it does not replace human decision making,” it said. “Officer are reminded during the training of the importance of making their own decisions on whether to engage with a member of the public or not.”

Civil society groups react

In response to the Westminster deployment, policy and campaigns director at human rights group Liberty, Emmanuelle Andrews, described facial recognition as “oppressive by design” and said “its inaccuracy and intrusion will fall most hard on people of colour, especially black men who face routine police oppression”.

He added: “The Court of Appeal has agreed that this technology violates our rights and threatens our liberty. Yet the Met has trialled it repeatedly. These tools are neither necessary nor compatible with the type of society we want to live in. To keep everyone safe, we must reject divisive and oppressive surveillance technology, we must reject ever-increasing and unaccountable police powers, and demand that government works with communities to develop strategies based in fairness, participation and support.”

Carlo said the facial recognition van at Oxford Street on 28 January was accompanied by a significant police presence, including around 25 uniformed officers and 25 plainclothes officers.

“The Metropolitan Police have been mired in scandals all year, and there are serious trust issues…to see such a huge deployment of police experimenting with a very intrusive technology whilst also handing out leaflets and having to explain to members of the public why they’re standing there staring at iPads, waiting for match alerts and scanning their faces seems extraordinary and very, very misguided to me,” she said.

This story has been updated to include information and comment from the MPS that was provided after publication.