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Police forces across the UK successfully lobbied to deploy a facial recognition system acknowledged as biased against women, youths, and individuals from ethnic minority groups, after complaining that a more accurate version generated fewer investigative leads.

The Technology in Practice

British police use the national police database to carry out searches using historical face recognition. This procedure involves matching a “probe image” of a suspect against a repository of more than 19 million custody photos to identify potential matches.

Acknowledged Discrimination

The UK interior ministry conceded last week that the system was biased. This admission came after a study by the government's National Physical Laboratory found it misidentified Black and Asian people and women at much greater frequency than white men. The Home Office said it “took steps on the findings”.

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

Long-Standing Problem

Internal documents show that this discriminatory flaw has been known about for over twelve months. Furthermore, law enforcement argued to overturn an earlier ruling that was designed to mitigate the problem.

Police bosses were notified of the algorithmic discrimination in late 2024. The government-ordered NPL review concluded the system was had a higher probability to produce false positives for photos of women, individuals of Black ethnicity, and those under 40 years old.

A Policy U-Turn

In reaction, the national police leadership body ordered that the accuracy setting required for possible hits be raised to a point where the bias was greatly diminished.

However, this directive was overturned the following month after forces complained that the adjusted system was generating a lower number of “useful lines of inquiry”. NPCC documents show the higher threshold reduced the proportion of queries resulting in potential matches from 56% to a just under 15%.

Severe Disparities

Although the authorities declined to specify what setting is now in operation, the latest independent review discovered the system could generate incorrect matches for women of Black heritage almost 100 times more often than for white women at specific configurations.

The ministry commented on these results: “The testing found that in a limited set of circumstances the algorithm is more likely to incorrectly include some demographic groups in its match reports.”

Operational Effectiveness vs. Bias

Describing the effect of the temporary raise to the system's accuracy setting, the NPCC documents note: “The change greatly lessens the effect of discrimination across legally safeguarded attributes of ethnicity, generation and gender but had a significant negative impact on police efficiency”. The documents further note that forces argued that “a once effective tactic now delivered results of questionable value”.

Broader Rollout Plans

Meanwhile, the UK administration has opened a ten-week public review on its proposals to widen the use of facial recognition technology. The minister for police Sarah Jones has labeled the technology as the “biggest breakthrough since genetic fingerprinting”.

Criticism from Advisors and Monitors

Abimbola Johnson, chair of the independent scrutiny and oversight board for the national policing equality strategy, said: “We observed scant discussion in equality strategy sessions of the facial recognition rollout even with clear relevance with the strategy's goals.

“This disclosure show once again that the anti-racism commitments the police has made via the race action plan are failing to be integrated into wider practice. Independent assessments have cautioned that new technologies are being implemented in a landscape where racial disparities, inadequate oversight and poor data collection already persist.

“Any use of facial recognition must adhere to rigorous official guidelines, be subject to external review, and prove it reduces rather than compounds ethnic bias.”

Home Office Response

A government representative stated: “The Home Office treat the conclusions of the study seriously and we have implemented changes. A updated software has been independently tested and procured, which has no statistically significant bias. It will be trialled early next year and will be undergo evaluation.

“The foremost aim is protecting the public. This revolutionary tool will assist police to apprehend and prosecute offenders. There is officer review in each stage of the process and no further action would be taken without specialist personnel carefully reviewing the results.”