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Police forces across the United Kingdom effectively campaigned to use a facial recognition system acknowledged as discriminatory against females, young people, and members of ethnic minority groups, following complaints that a more accurate version produced a reduced number of potential suspects.

The Technology in Practice

UK forces utilize the police national database (PND) to carry out retrospective facial recognition searches. This procedure entails comparing a “probe image” of a suspect against a repository of over 19 million mugshots to find possible hits.

Acknowledged Discrimination

The Home Office conceded last week that the system was biased. This admission followed a study by the government's National Physical Laboratory found it incorrectly matched Black and Asian people and females at much greater frequency than white men. The Home Office stated it “took steps on the findings”.

“This raises the question of whether facial recognition only becomes effective if users accept discrimination in race and sex. Operational ease is a weak argument for disregarding fundamental rights.”

Long-Standing Problem

Official papers show that this bias has been known about for more than a year. Furthermore, law enforcement lobbied to reverse an initial decision that was intended to address the problem.

Police bosses were informed of the algorithmic discrimination in September 2024. The Home Office-commissioned NPL review found the system was more likely to suggest incorrect matches for photos of women, individuals of Black ethnicity, and those aged 40 and under.

A Policy U-Turn

In reaction, the National Police Chiefs’ Council (NPCC) mandated that the confidence threshold required for potential matches be raised 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 generating fewer “investigative leads”. NPCC documents show the stricter setting reduced the proportion of searches resulting in potential matches from 56% to a mere under 15%.

Severe Disparities

Although the authorities declined to specify what threshold is currently used, the recent NPL study discovered the system could generate incorrect matches for Black women nearly a hundred times more frequently than for Caucasian women at certain settings.

The ministry commented on these results: “Our evaluation identified that in a specific scenarios the algorithm is has a greater tendency to wrongly flag some demographic groups in its search results.”

Balancing Utility and Fairness

Outlining the impact of the temporary raise to the system's accuracy setting, the NPCC documents state: “The change greatly lessens the effect of discrimination across protected characteristics of race, age and gender but had a substantially detrimental effect on operational effectiveness”. The papers add that forces complained that “a previously useful tool returned outcomes of questionable value”.

Wider Implementation Proposals

Meanwhile, the government has opened a ten-week consultation on its proposals to expand the use of biometric scanning systems. Policing minister the relevant minister has labeled the tool as the “most significant advance since genetic fingerprinting”.

Expert and Oversight Concerns

Abimbola Johnson, chair of the advisory panel for the national policing equality strategy, commented: “There was scant discussion in equality strategy sessions of the technology deployment even with obvious cross-over with the strategy's goals.

“This disclosure demonstrate once again that the anti-racism commitments policing has undertaken through the equality initiative are not being translated into wider practice. Our reports have cautioned that new technologies are being rolled out in a context where racial disparities, inadequate oversight and faulty information gathering already persist.

“All deployment of facial recognition must meet strict national standards, be independently scrutinised, and prove it diminishes rather than compounds ethnic bias.”

Official Statement

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

“The foremost aim is ensuring public safety. This revolutionary tool will assist officers to apprehend and prosecute offenders. There is officer review in every step of the procedure and no further action would be taken without trained officers carefully reviewing the results.”