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Law enforcement agencies across the UK successfully lobbied to use a facial recognition system acknowledged as biased against women, youths, and members of ethnic minority groups, following complaints that a less biased version generated fewer investigative leads.

The Technology in Practice

UK forces use the national police database to carry out retrospective facial recognition searches. This procedure involves matching a “probe image” of a person of interest against a database of over 19 million mugshots to find possible hits.

Acknowledged Discrimination

The UK interior ministry admitted last week that the system was biased. This admission came after a study by the National Physical Laboratory (NPL) determined it misidentified Black and Asian people and women at much greater frequency than Caucasian males. The ministry stated it “had acted on the findings”.

“It prompts the issue of whether this technology only becomes useful if users accept discrimination in ethnicity and sex. Convenience is a weak argument for disregarding fundamental rights.”

Long-Standing Problem

Internal documents show that this discriminatory flaw has been recognized for more than a year. Furthermore, police forces lobbied to reverse an earlier ruling that was designed to address the problem.

Police bosses were notified of the algorithmic discrimination in late 2024. The government-ordered NPL review found the system was had a higher probability to suggest false positives for images depicting women, Black people, and those under 40 years old.

A Policy U-Turn

In reaction, the national police leadership body mandated that the accuracy setting required for potential matches be raised to a point where the bias was greatly diminished.

However, this decision was overturned the next month following complaints from police that the modified technology was generating a lower number of “investigative leads”. Internal records show the higher threshold cut the number of queries resulting in potential matches from over half to a just 14%.

Profound Inequalities

Although the Home Office and NPCC refused to say what threshold is now in operation, the latest independent review discovered the system could produce incorrect matches for women of Black heritage almost 100 times more frequently than for Caucasian women at specific configurations.

The ministry commented on these results: “The testing found that in a specific scenarios the algorithm is has a greater tendency to wrongly flag some demographic groups in its match reports.”

Balancing Utility and Fairness

Describing the impact of the brief increase to the system's confidence threshold, the police records state: “This adjustment greatly lessens the impact of bias across legally safeguarded attributes of race, generation and gender but had a substantially detrimental effect on police efficiency”. The papers add that police units complained that “a once effective tactic 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 widen the use of facial recognition technology. Policing minister the relevant minister has described the tool as the “most significant advance since genetic fingerprinting”.

Criticism from Advisors and Monitors

The chair of a police oversight board, chair of the independent scrutiny and oversight board for the police race action plan, said: “There was very little discussion in equality strategy sessions of the facial recognition rollout despite obvious cross-over with the plan’s concerns.

“These revelations show yet again that the anti-racism commitments policing has made through the race action plan are failing to be integrated into wider practice. Our reports have warned that innovative tools are being implemented in a context where ethnic inequalities, inadequate oversight and poor data collection already persist.

“Any use of facial recognition must meet strict national standards, be subject to external review, and prove it reduces rather than compounds ethnic bias.”

Official Statement

A government representative stated: “We treat the findings of the study with utmost gravity and we have already taken action. A updated software has been independently tested and acquired, which has no statistically significant bias. It will be trialled in the coming months and will be undergo evaluation.

“The foremost aim is protecting the public. This revolutionary tool will support officers to put criminals and rapists behind bars. There is human involvement in each stage of the procedure and no arrest or charge would be pursued without trained officers meticulously examining the output.”