Facial Recognition

Facial Recognition (FR) technology can be used in a number of ways by the Met, including to prevent and detect crime, find wanted criminals, safeguard vulnerable people, and to protect people from harm – all to keep the people we serve safe.

Whilst the Met’s documents you can find linked from this page give you a lot more detail about the terms we use as well as how and where FR is used by the Met. The typical uses of FR technology for policing are:

• as a real-time aid to help officers to help them locate people on a ‘watchlist’ who are sought by the police;
• as an operator initiated tool for officers who decide they need to take an image of a person and then use Facial Recognition software to help them establish who that person is. This helps the police even if that person provides false or misleading details. This use of FR can also help provide an identification of someone who is unconscious or seriously injured and unable to communicate who they are;
• as a retrospective system to be used after an event to help officers establish who a person is or whether their image matches against other media held on databases.  

Live Facial Recognition

LFR cameras are focused on a specific area; when people pass through that area their images are streamed directly to the Live Facial Recognition system.

This system contains a watchlist: a list of offenders wanted by the police and/or the courts, or those who pose a risk of harm to themselves or others. Further details of who can be on a watchlist and how the Met carefully decides where to use LFR can be found in our Standard Operating Procedures for LFR.

LFR is not a ubiquitous tool that uses lots of CCTV cameras from across London to track every person’s movements. It is a carefully deployed overt policing tactic to help locate a limited number of people the police need to find in order to keep London safe.

Operational testing by the Met

Why are we testing?

The Met is testing its facial recognition algorithms with the National Physical Laboratory (NPL). Thanks to previous testing by the National Institute of Standards and Technology (NIST) we know that our Live Facial Recognition (LFR) system uses a high performing algorithm but we want to have an ongoing understanding of the performance of the technology we use, and to identify any impact on relevant characteristics, in particular race and sex.

This testing will further enable us to understand more about the algorithm's accuracy and if any biases have been detected. The data for these tests needs to be collected in a realistic operational policing environment and therefore this data will be collected whilst a number of LFR deployments are happening. The results of this testing will help inform the Met how we use facial recognition technology legally and fairly in order to prevent and detect crime, safeguard national security and keep Londoners safe.

What will the testing involve?

The testing will run alongside a number of authorised LFR operational deployments. Volunteers of all ages and backgrounds will walk past the facial recognition system along with members of the public. 

After the testing is complete, the data from the volunteers and the CCTV footage will be kept by the Met and for a longer period than we would normally hold it for. This retention period is currently set at three years and is then subject to review. 

This is so that after the deployments are completed, scientific and technology experts at the NPL can review the data and produce a report on how the algorithms have performed and how we may wish to use the new facial recognition algorithms in the future. We will make these findings public.

The data that has been collected may also be made available to the UK law enforcement community and its partners. South Wales Police are also going to be undertaking similar testing with the NPL as part of this study.

Further information about the testing can be found in the test strategy document and the DPIA Annex.

Please note: The PDFs on this page may not be suitable for users of assistive technology. We are in the process of updating them, but please email us to request an accessible version. See our accessibility statement.

• FRT Equitability Study Plan
• Process Summary
• Appropriate Policy Annex
• DPIA Annex
• EIA Annex

Data rights in relation to our operational testing.

Should you have questions about personal data, you can email the Met data office. Or, you can write to the data controller at:
c/o MPS Data Office
PO Box 313
Sidcup
DA15 0HH

Or see the Met Privacy Notice for more information. 

Retrospective Facial Recognition

The Met is updating the technology we will use for Retrospective Facial Recognition. We are currently working to integrate the updated capability and develop a suite of documents to ensure we have the right controls and safeguards in place to use the technology. We are in touch with the London Policing Ethics Panel and engaging with key stakeholders in this process to ensure our use is lawful, ethical and informed. Prior to operational use, we will publish documents that set out how the technology will be used.

Operator Initiated Facial Recognition

The Met keeps its need to use Facial Recognition technologies under review but does not presently use Operator Initiated Facial Recognition. Further details about Operator Initiated Facial Recognition can be found in the Met’s Live Facial Recognition Policy document where we set out the different types of Facial Recognition technology and how we refer to them.