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Law enforcement agencies across the UK effectively campaigned to use a facial recognition system known to be biased against women, youths, and members of minority ethnic backgrounds, following complaints that a less biased version produced fewer potential suspects.

How the System Works

UK forces use the national police database to conduct searches using historical face recognition. This procedure entails comparing a reference photograph of a suspect against a repository of more than 19 million custody photos to identify potential matches.

Admitted Bias

The Home Office conceded last week that the system was biased. This admission followed a review by the government's National Physical Laboratory determined it misidentified people of Black and Asian heritage and females at much greater frequency than white men. The ministry said 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. Convenience is a weak argument for disregarding basic freedoms.”

Long-Standing Problem

Internal documents show that this discriminatory flaw has been recognized for over twelve months. Furthermore, police forces lobbied to reverse an initial decision that was intended to address the problem.

Senior officers were informed of the algorithmic discrimination in late 2024. The Home Office-commissioned laboratory study found the system was had a higher probability to suggest false positives for photos of females, Black people, and those aged 40 and under.

A Policy U-Turn

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 decision was overturned the following month after forces complained that the adjusted system was generating fewer “useful lines of inquiry”. Internal records indicate the stricter setting cut the number of queries resulting in possible identifications from 56% to a mere 14%.

Profound Inequalities

Although the authorities refused to say what threshold is now in operation, the latest independent review found the system could generate false positives for Black women nearly a hundred times more frequently than for Caucasian women at certain settings.

The Home Office stated on these results: “Our evaluation found that in a specific scenarios the software is has a greater tendency to wrongly flag some population segments in its match reports.”

Balancing Utility and Fairness

Outlining the effect of the brief increase to the system's accuracy setting, the NPCC documents state: “The change greatly lessens the effect of discrimination across protected characteristics of race, generation and gender but had a significant negative impact on police efficiency”. The papers add that police units argued that “a once effective tactic now delivered outcomes of questionable value”.

Wider Implementation Proposals

Meanwhile, the UK administration has opened a two-and-a-half-month public review on its proposals to widen the use of biometric scanning systems. Policing minister the relevant minister has described the technology as the “biggest breakthrough since genetic fingerprinting”.

Criticism from Advisors and Monitors

Abimbola Johnson, chair of the independent scrutiny and oversight board for the national policing equality strategy, said: “There was scant discussion in equality strategy sessions of the facial recognition rollout despite obvious cross-over with the strategy's goals.

“These revelations show yet again that the anti-racism commitments the police has made through the race action plan are failing to be integrated into wider practice. Independent assessments have warned that new technologies are being implemented in a context where ethnic inequalities, inadequate oversight and poor data collection continue to exist.

“Any use of facial recognition must meet strict national standards, be independently scrutinised, and prove it diminishes rather than exacerbates racial disparity.”

Home Office Response

A Home Office spokesperson stated: “The Home Office treat the findings of the report with utmost gravity and we have implemented changes. 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 gamechanging technology will assist officers to put criminals and rapists behind bars. There is human involvement in each stage of the process and no further action would be pursued without trained officers carefully reviewing the output.”