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Police forces across the UK successfully lobbied to deploy a face scanning system known to be discriminatory against females, youths, and members of ethnic minority groups, after complaining that a less biased version produced fewer investigative leads.

The Technology in Practice

UK forces utilize the national police database to carry out retrospective facial recognition searches. This process involves matching a “probe image” 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 followed a review by the government's National Physical Laboratory found it incorrectly matched people of Black and Asian heritage and females at significantly higher rates than white men. The Home Office stated it “took steps on the findings”.

“It prompts the issue of whether facial recognition only becomes effective if users tolerate biases in race and sex. Convenience is a poor argument for disregarding fundamental rights.”

Long-Standing Problem

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

Senior officers were informed of the algorithmic discrimination in September 2024. The government-ordered laboratory study concluded the system was more likely to produce incorrect matches for photos of women, individuals of Black ethnicity, and those under 40 years old.

A Reversed Decision

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

However, this decision was reversed the next month after forces complained that the adjusted system was producing a lower number of “investigative leads”. NPCC documents indicate the stricter setting cut the number of searches resulting in possible identifications from over half to a mere 14%.

Severe Disparities

Although the Home Office and NPCC declined to specify what setting is currently used, the latest independent review discovered the system could generate incorrect matches for women of Black heritage nearly a hundred times more frequently than for Caucasian women at specific configurations.

The ministry stated on these results: “Our evaluation identified that in a limited set of circumstances the algorithm is has a greater tendency to wrongly flag some demographic groups in its match reports.”

Operational Effectiveness vs. Bias

Outlining the impact of the brief increase to the system's confidence threshold, the police records note: “This adjustment greatly lessens the effect of discrimination across protected characteristics of race, generation and sex but had a significant negative impact on operational effectiveness”. The papers further note that forces complained that “a previously useful tool now delivered outcomes of questionable value”.

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. The minister for police the relevant minister has labeled the technology as the “biggest breakthrough since genetic fingerprinting”.

Expert and Oversight Concerns

The chair of a police oversight board, chair of the advisory panel for the national policing equality strategy, commented: “There was very little consideration through race action plan meetings of the facial recognition rollout even with obvious cross-over with the strategy's goals.

“These revelations show yet again that the anti-racism commitments policing has undertaken through the equality initiative are not being translated into broader operations. Independent assessments have warned that innovative tools are being implemented in a landscape where ethnic inequalities, inadequate oversight and faulty information gathering already persist.

“Any use of this technology must adhere to strict national standards, be independently scrutinised, and prove it diminishes rather than compounds ethnic bias.”

Home Office Response

A Home Office spokesperson said: “We treat the conclusions of the report seriously and we have already taken action. A updated software has been externally evaluated and acquired, which has no statistically significant bias. It will be tested early next year and will be undergo evaluation.

“The foremost aim is ensuring public safety. This revolutionary tool will support officers to put criminals and rapists behind bars. There is officer review in each stage of the process and no arrest or charge would be pursued without specialist personnel carefully reviewing the results.”