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Police forces across the UK successfully lobbied to use a facial recognition system acknowledged as discriminatory against women, young people, and individuals from ethnic minority groups, after complaining that a less biased version produced a reduced number of potential suspects.

How the System Works

British police use the national police database to conduct retrospective facial recognition searches. This procedure entails matching a reference photograph of a suspect against a database of more than 19 million mugshots to identify potential matches.

Acknowledged Discrimination

The Home Office conceded last week that the system was flawed. This admission came after a study by the government's National Physical Laboratory determined it misidentified Black and Asian people and women at much greater frequency than Caucasian males. The Home Office stated it “took steps on the findings”.

“This raises the question of whether facial recognition only becomes useful if users tolerate biases in ethnicity and gender. Operational ease is a poor argument for overriding fundamental rights.”

Known Issue

Official papers show that this discriminatory flaw has been known about for over twelve months. Furthermore, law enforcement lobbied to reverse an earlier ruling that was intended to mitigate the problem.

Senior officers were informed of the system's bias in late 2024. The Home Office-commissioned NPL review concluded the system was had a higher probability to suggest false positives for images depicting females, Black people, and those aged 40 and under.

A Reversed Decision

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

However, this directive was overturned the following month after forces complained that the adjusted system was producing fewer “useful lines of inquiry”. NPCC documents indicate the higher threshold cut the proportion of searches that yielded possible identifications from over half to a just under 15%.

Profound Inequalities

Although the authorities refused to say what threshold is currently used, the latest independent review discovered the system could generate incorrect matches for women of Black heritage almost 100 times more often than for Caucasian women at specific configurations.

The Home Office commented on these results: “The testing identified that in a limited set of circumstances the algorithm is more likely to wrongly flag some population segments in its search results.”

Balancing Utility and Fairness

Describing the effect of the temporary raise to the system's confidence threshold, the police records state: “This adjustment significantly reduces the impact of discrimination across legally safeguarded attributes of ethnicity, age and gender but had a significant negative impact on police efficiency”. The documents add that forces complained that “a previously useful tool returned results of questionable value”.

Broader Rollout Plans

Meanwhile, the government has launched a ten-week consultation on its plans to widen the use of biometric scanning systems. Policing minister Sarah Jones has labeled the tool as the “biggest breakthrough since DNA matching”.

Expert and Oversight Concerns

Abimbola Johnson, head of the independent scrutiny and oversight board for the police race action plan, commented: “There was very little discussion through race action plan meetings of the facial recognition rollout even with obvious cross-over with the strategy's goals.

“This disclosure demonstrate once again that the pledges to combat discrimination the police has undertaken through the equality initiative are not being translated into wider practice. Independent assessments have warned that new technologies are being rolled out in a landscape where ethnic inequalities, inadequate oversight and poor data collection continue to exist.

“Any use of facial recognition must meet rigorous official guidelines, be subject to external review, and demonstrate it reduces rather than compounds racial disparity.”

Home Office Response

A Home Office spokesperson said: “We takes the conclusions of the report 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 subject to evaluation.

“Our priority is protecting the public. This revolutionary tool will support officers to apprehend and prosecute offenders. There is officer review in every step of the process and no further action would be taken without specialist personnel meticulously examining the output.”