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Law enforcement agencies across the UK successfully lobbied to deploy a face scanning system acknowledged as discriminatory against women, young people, and members of ethnic minority groups, after complaining that a more accurate version generated fewer potential suspects.

How the System Works

UK forces utilize the police national database (PND) 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 mugshots to identify potential matches.

Acknowledged Discrimination

The Home Office admitted last week that the system was biased. This admission followed a study by the National Physical Laboratory (NPL) determined it incorrectly matched people of Black and Asian heritage and females at much greater frequency than Caucasian males. The ministry stated it “had acted on the findings”.

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

Known Issue

Official papers show that this discriminatory flaw has been recognized for over twelve months. Furthermore, police forces argued to overturn an initial decision that was intended to mitigate the problem.

Police bosses were informed of the system's bias in September 2024. The government-ordered NPL review concluded the system was had a higher probability to suggest false positives for images depicting females, individuals of Black ethnicity, and those under 40 years old.

A Reversed Decision

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

However, this directive was reversed the following month after forces complained that the adjusted system was producing fewer “investigative leads”. NPCC documents show the stricter setting cut the proportion of searches that yielded potential matches from 56% to a mere 14%.

Severe Disparities

Although the authorities declined to specify what setting is now in operation, the recent NPL study found the system could produce incorrect matches for women of Black heritage nearly a hundred times more frequently than for white women at certain settings.

The ministry commented on these findings: “Our evaluation found that in a limited set of circumstances the software is more likely to wrongly flag some demographic groups in its match reports.”

Operational Effectiveness vs. Bias

Describing the impact of the brief increase to the system's confidence threshold, the NPCC documents note: “This adjustment greatly lessens the effect of discrimination across protected characteristics of race, age and sex but had a substantially detrimental effect on police efficiency”. The documents add that forces complained that “a once effective tactic returned results of limited benefit”.

Broader Rollout Plans

Meanwhile, the government has opened a two-and-a-half-month 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 “most significant advance 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, said: “We observed very little discussion through race action plan meetings of the technology deployment even with clear relevance with the plan’s concerns.

“This disclosure demonstrate yet again that the anti-racism commitments policing has made through the race action plan are failing to be integrated into broader operations. Our reports have cautioned that innovative tools are being implemented in a landscape where ethnic inequalities, weak scrutiny and poor data collection continue to exist.

“Any use of this technology must meet rigorous official guidelines, be independently scrutinised, and prove it reduces rather than exacerbates racial disparity.”

Official Statement

A Home Office spokesperson said: “The Home Office treat the findings of the study seriously 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.

“The foremost aim is protecting the public. This revolutionary tool will support officers to put criminals and rapists behind bars. There is officer review in each stage of the procedure and no arrest or charge would be taken without trained officers carefully reviewing the results.”