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Law enforcement agencies across the United Kingdom successfully lobbied to use a face scanning system known to be discriminatory against females, young people, and members of minority ethnic backgrounds, following complaints that a less biased version generated fewer potential suspects.

The Technology in Practice

British police use the national police database to carry out searches using historical face recognition. This procedure entails comparing a reference photograph of a suspect against a database of over 19 million custody photos to identify potential matches.

Admitted Bias

The Home Office admitted last week that the technology was biased. This acknowledgment came after a review by the government's National Physical Laboratory determined it incorrectly matched Black and Asian people and females at significantly higher rates than Caucasian males. The ministry stated it “took steps on the findings”.

“This raises the issue of whether this technology only becomes useful if users accept discrimination in race and gender. Convenience is a weak argument for overriding fundamental rights.”

Known Issue

Internal documents show that this discriminatory flaw has been known about for more than a year. Furthermore, law enforcement lobbied to reverse an initial decision that was designed to address the problem.

Police bosses were informed of the system's bias in September 2024. The government-ordered NPL review concluded the system was more likely to suggest false positives for images depicting women, Black people, and those under 40 years old.

A Policy U-Turn

In reaction, the national police leadership body ordered that the accuracy setting required for potential matches be increased to a level where the bias was significantly reduced.

However, this directive was reversed the next month following complaints from police that the modified technology was producing fewer “useful lines of inquiry”. NPCC documents show the stricter setting cut the proportion of searches resulting in potential matches from over half to a mere under 15%.

Severe Disparities

Although the authorities refused to say what setting is now in operation, the recent NPL study found the system could produce incorrect matches for Black women nearly a hundred times more often than for Caucasian women at certain settings.

The Home Office commented on these findings: “The testing identified that in a limited set of circumstances the software is more likely to wrongly flag some demographic groups in its search results.”

Operational Effectiveness vs. Bias

Describing the impact of the temporary raise to the system's accuracy setting, the NPCC documents state: “The change significantly reduces the impact of discrimination across legally safeguarded attributes of race, age and sex but had a significant negative impact on police efficiency”. The papers add that forces complained that “a previously useful tool now delivered outcomes of questionable value”.

Wider Implementation Proposals

Meanwhile, the UK administration has launched a two-and-a-half-month public review on its plans to widen the use of facial recognition technology. Policing minister Sarah Jones has labeled the technology as the “biggest breakthrough since genetic fingerprinting”.

Expert and Oversight Concerns

The chair of a police oversight board, head of the advisory panel for the police race action plan, commented: “We observed very little discussion in equality strategy sessions of the technology deployment even with clear relevance with the plan’s concerns.

“These revelations show yet again that the anti-racism commitments policing has undertaken via the equality initiative are failing to be integrated into wider practice. Independent assessments have cautioned that new technologies are being rolled out in a landscape where racial disparities, inadequate oversight and faulty information gathering already persist.

“All deployment of this technology must meet strict national standards, be subject to external review, and prove it reduces rather than exacerbates ethnic bias.”

Official Statement

A Home Office spokesperson stated: “We treat the conclusions of the report seriously and we have already taken action. A updated software has been independently tested and procured, which has no statistically significant bias. It will be tested in the coming months and will be subject to evaluation.

“The foremost aim is ensuring public safety. This gamechanging technology will support officers to apprehend and prosecute offenders. There is human involvement in each stage of the process and no further action would be taken without specialist personnel meticulously examining the output.”