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Biometrics: Police National Database

Answer

The Home Office is aware of the risk of bias in facial recognition algorithms and supports policing in managing that risk. Hence the Home Office, in collaboration with the Office of the Police Chief Scientific Adviser and the National Police Chiefs’ Council, commissioned independent testing of the facial recognition algorithm currently used by specially trained operators in police forces to search the Police National Database. Contracts were agreed in March 2024.

Independent testing helps to ensure algorithms are used at settings where statistically significant bias is reduced to negligible levels. Where potential bias is identified, the Home Office supports policing to ensure they have the operational processes in place to ensure the risk of any material impact is minimised.

Manual safeguards, embedded in police training, operational practice, and guidance, require all potential matches returned from the Police National Database to be checked by a trained user and investigating officer. These safeguards pre-date the National Physical Laboratory testing but they were reviewed once the results were known.

Home Office Ministers were first made aware of a bias in the algorithm used by specially trained operators in police forces to search the Police National Database in October 2024. Initial findings were shared with the Home Office between March 2024 and October 2024, and the final report was provided by NPL in April 2025 and updated for publication in October 2025.

A replacement system with a new algorithm has also been procured by the Home Office and independently tested. This testing has been published and shows that the system can be used with no statistically significant bias. It is due to be operationally tested early next year and will be subject to further evaluation.

The Home Office briefed the Information Commissioners Office on the findings of the independent report ahead of its publication and we continue to work closely with the ICO as we consult on a new legal framework for law enforcement use of biometrics, facial recognition and similar technologies.

The Home Office has also commissioned His Majesty’s Inspectorate of Constabulary and Fire & Rescue Services, with support from the Forensic Science Regulator, to conduct an inspection of police and relevant law enforcement agencies’ use of retrospective facial recognition.

Secondary information

Type

Written question

Reference

HL12796

Session

2024-26

Grouped for answer

Yes

Subjects

Biometrics Police national database

Link

View this Written question on www.parliament.uk