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Police forces across the UK successfully lobbied to use a face scanning system acknowledged as discriminatory against women, youths, and members of minority ethnic backgrounds, following complaints that a more accurate version generated fewer investigative leads.

How the System Works

UK forces utilize the police national database (PND) to conduct searches using historical face recognition. This process entails comparing a reference photograph of a suspect against a database of over 19 million custody photos to identify potential matches.

Acknowledged Discrimination

The UK interior ministry admitted last week that the technology was flawed. This acknowledgment came after a review by the National Physical Laboratory (NPL) determined it incorrectly matched people of Black and Asian heritage and women at significantly higher rates than white men. The ministry said it “took steps on the findings”.

“It prompts the issue of whether facial recognition only becomes effective if users accept biases in race and gender. Convenience is a poor argument for overriding basic freedoms.”

Known Issue

Official papers reveal that this bias has been recognized for over twelve months. Furthermore, police forces lobbied to reverse an initial decision that was intended to address the problem.

Senior officers were informed of the algorithmic discrimination in late 2024. The Home Office-commissioned laboratory study concluded the system was more likely to produce false positives for images depicting women, Black people, and those aged 40 and under.

A Policy U-Turn

In reaction, the National Police Chiefs’ Council (NPCC) mandated that the accuracy setting required for possible hits be raised to a point where the bias was greatly diminished.

However, this decision was reversed the next month following complaints from police that the adjusted system was generating fewer “useful lines of inquiry”. Internal records indicate the higher threshold reduced the number of searches that yielded potential matches from 56% to a mere under 15%.

Severe Disparities

Although the Home Office and NPCC declined to specify what setting is currently used, the recent NPL study discovered the system could generate incorrect matches for women of Black heritage nearly a hundred times more often than for white women at certain settings.

The Home Office stated on these findings: “The testing found that in a limited set of circumstances the algorithm is has a greater tendency to incorrectly include some demographic groups in its search results.”

Operational Effectiveness vs. Bias

Outlining the impact of the brief increase to the system's accuracy setting, the NPCC documents state: “This adjustment significantly reduces the effect of discrimination across legally safeguarded attributes of ethnicity, age and gender but had a significant negative impact on operational effectiveness”. The documents add that forces complained that “a once effective tactic now delivered outcomes of questionable value”.

Wider Implementation Proposals

Meanwhile, the UK administration has opened a two-and-a-half-month consultation on its proposals to widen the use of facial recognition technology. Policing minister Sarah Jones has labeled the technology as the “most significant advance since DNA matching”.

Expert and Oversight Concerns

Abimbola Johnson, chair of the advisory panel for the police race action plan, commented: “There was very little discussion in equality strategy sessions of the technology deployment despite clear relevance with the strategy's goals.

“This disclosure demonstrate yet again that the anti-racism commitments policing has undertaken through the race action plan are failing to be integrated into broader operations. Independent assessments have cautioned that new technologies are being implemented in a context where racial disparities, inadequate oversight and faulty information gathering already persist.

“All deployment of this technology must meet strict national standards, be independently scrutinised, and prove it reduces rather than exacerbates racial disparity.”

Home Office Response

A government representative said: “We treat the conclusions of the study with utmost gravity and we have already taken action. A updated software has been externally evaluated and procured, which has no statistically significant bias. It will be trialled in the coming months and will be undergo further assessment.

“Our priority is ensuring public safety. This revolutionary tool will support officers to put criminals and rapists behind bars. There is officer review in every step of the process and no further action would be pursued without trained officers carefully reviewing the results.”