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Police forces across the United Kingdom effectively campaigned to use a facial recognition system acknowledged as biased against females, young people, and members of minority ethnic backgrounds, following complaints that a more accurate version generated a reduced number of potential suspects.

How the System Works

British police use the national police database to conduct retrospective facial recognition searches. This process involves comparing a reference photograph of a person of interest against a database of more than 19 million mugshots to identify possible hits.

Admitted Bias

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 misidentified people of Black and Asian heritage and females at much greater frequency than white men. The Home Office stated it “took steps on the findings”.

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

Known Issue

Official papers reveal that this bias has been recognized for over twelve months. Furthermore, law enforcement argued to overturn an initial decision that was designed to mitigate the problem.

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

A Policy U-Turn

In response, the national police leadership body mandated that the accuracy setting required for potential matches be raised to a level where the disparity was significantly reduced.

However, this decision was reversed the following month following complaints from police that the adjusted system was generating fewer “investigative leads”. Internal records indicate the higher threshold reduced the number of searches resulting in possible identifications from 56% to a mere under 15%.

Profound Inequalities

Although the authorities declined to specify what setting is currently used, the recent NPL study found the system could produce incorrect matches for Black women nearly a hundred times more often than for white women at specific configurations.

The ministry commented on these findings: “The testing identified that in a limited set of circumstances the algorithm is has a greater tendency to incorrectly include some population segments in its match reports.”

Balancing Utility and Fairness

Describing the effect of the temporary raise to the system's accuracy setting, the NPCC documents state: “The change greatly lessens the effect of bias across legally safeguarded attributes of race, age and gender but had a substantially detrimental effect on police efficiency”. The papers add that forces argued that “a previously useful tool now delivered results of limited benefit”.

Broader Rollout Plans

Meanwhile, the UK administration has launched a two-and-a-half-month consultation on its plans to expand the use of facial recognition technology. Policing minister Sarah Jones has described the tool as the “biggest breakthrough since DNA matching”.

Criticism from Advisors and Monitors

Abimbola Johnson, head of the advisory panel for the police race action plan, said: “We observed very little 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 policing has undertaken through the race action plan are not being translated into wider practice. Our reports have cautioned that innovative tools are being implemented in a context where ethnic inequalities, weak scrutiny and poor data collection already persist.

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

Home Office Response

A Home Office spokesperson stated: “The Home Office takes the conclusions of the report 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 in the coming months and will be subject to evaluation.

“Our priority is protecting the public. This gamechanging technology will assist police to apprehend and prosecute offenders. There is human involvement in each stage of the process and no further action would be pursued without specialist personnel meticulously examining the results.”