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Police forces across the United Kingdom effectively campaigned to use a facial recognition system acknowledged as discriminatory against women, youths, and individuals from ethnic minority groups, following complaints that a less biased version generated a reduced number of investigative leads.

The Technology in Practice

UK forces use the national police database to carry out searches using historical face recognition. This process entails matching a reference photograph of a person of interest against a database of over 19 million mugshots to find potential matches.

Admitted Bias

The UK interior ministry conceded last week that the technology was biased. This admission came after a review by the government's National Physical Laboratory found it misidentified people of Black and Asian heritage and women at much greater frequency than Caucasian males. The Home Office said it “had acted on the findings”.

“This raises the issue of whether facial recognition only becomes useful if users tolerate biases in ethnicity and gender. Operational ease is a weak argument for disregarding basic freedoms.”

Long-Standing Problem

Internal documents show that this bias has been recognized for over twelve months. Furthermore, police forces lobbied to reverse an earlier ruling that was intended to mitigate the problem.

Police bosses were informed of the algorithmic discrimination in September 2024. The government-ordered laboratory study concluded the system was had a higher probability to produce incorrect matches for images depicting women, Black people, and those aged 40 and under.

A Policy U-Turn

In reaction, the National Police Chiefs’ Council (NPCC) ordered that the confidence threshold required for possible hits be raised to a level where the bias was significantly reduced.

However, this directive was reversed the next month after forces complained that the adjusted system was producing fewer “investigative leads”. NPCC documents indicate the stricter setting cut the number of searches resulting in potential matches from over half to a just 14%.

Profound Inequalities

Although the authorities refused to say what setting is currently used, the recent NPL study found the system could generate incorrect matches for Black women nearly a hundred times more frequently than for Caucasian women at certain settings.

The Home Office commented on these results: “Our evaluation identified that in a specific scenarios the software is has a greater tendency to incorrectly include some population segments in its match reports.”

Balancing Utility and Fairness

Describing the impact of the brief increase to the system's accuracy setting, the police records note: “The change greatly lessens the impact of bias across legally safeguarded attributes of race, generation and sex but had a substantially detrimental effect on police efficiency”. The papers add that forces argued that “a once effective tactic now delivered outcomes of limited benefit”.

Wider Implementation Proposals

Meanwhile, the government has launched a two-and-a-half-month consultation on its plans to widen the use of facial recognition technology. The minister for police the relevant minister has described the tool 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: “We observed scant consideration through race action plan meetings of the technology deployment despite clear relevance with the plan’s concerns.

“This disclosure demonstrate yet again that the pledges to combat discrimination the police has undertaken through the equality initiative are not being translated into broader operations. Independent assessments have cautioned that new technologies are being rolled out in a landscape where racial disparities, inadequate oversight and faulty information gathering continue to exist.

“All deployment of facial recognition must adhere to strict national standards, be independently scrutinised, and demonstrate it reduces rather than compounds racial disparity.”

Home Office Response

A government representative stated: “The Home Office takes the findings of the report with utmost gravity and we have already taken action. A updated software has been externally evaluated and procured, which has demonstrated no measurable discrimination. It will be tested early next year and will be undergo evaluation.

“Our priority is ensuring public safety. This revolutionary tool will assist officers to apprehend and prosecute offenders. There is human involvement in each stage of the procedure and no arrest or charge would be taken without specialist personnel carefully reviewing the output.”