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Law enforcement agencies across the UK successfully lobbied to use a facial recognition system acknowledged as biased against females, youths, and members of minority ethnic backgrounds, following complaints that a less biased version generated a reduced number of potential suspects.

The Technology in Practice

British police utilize the national police database to carry out retrospective facial recognition searches. This process involves comparing a reference photograph of a suspect against a repository of over 19 million custody photos to find potential matches.

Admitted Bias

The UK interior ministry admitted last week that the technology was flawed. This acknowledgment followed a review by the National Physical Laboratory (NPL) determined it incorrectly matched people of Black and Asian heritage and females at significantly higher rates than white men. The ministry said it “had acted on the findings”.

“This raises the issue of whether this technology only becomes effective if users accept biases in ethnicity and gender. Operational ease is a poor argument for disregarding basic freedoms.”

Long-Standing Problem

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

Police bosses were notified of the system's bias in September 2024. The government-ordered laboratory study concluded the system was had a higher probability to suggest incorrect matches for images depicting women, individuals of Black ethnicity, and those under 40 years old.

A Policy U-Turn

In response, the national police leadership body mandated that the confidence threshold required for potential matches be raised to a level where the bias was significantly reduced.

However, this decision was overturned the following month after forces complained that the modified technology was producing fewer “investigative leads”. Internal records show the higher threshold reduced the proportion of queries resulting in possible identifications from 56% to a just under 15%.

Severe Disparities

Although the authorities declined to specify what threshold is now in operation, the latest independent review found the system could produce incorrect matches for Black women nearly a hundred times more often than for Caucasian women at certain settings.

The Home Office commented on these results: “Our evaluation identified that in a limited set of circumstances the software is has a greater tendency to incorrectly include some population segments in its search results.”

Balancing Utility and Fairness

Describing the effect of the temporary raise to the system's accuracy setting, the NPCC documents note: “This adjustment significantly reduces the impact of bias across protected characteristics of ethnicity, generation and sex but had a substantially detrimental effect on operational effectiveness”. The papers add that forces complained that “a once effective tactic now delivered outcomes of questionable value”.

Broader Rollout Plans

Meanwhile, the UK administration has launched a ten-week public review on its plans to expand the use of facial recognition technology. Policing minister the relevant minister has described the technology as the “most significant advance since DNA matching”.

Criticism from Advisors and Monitors

Abimbola Johnson, head of the advisory panel for the national policing equality strategy, commented: “There was scant discussion in equality strategy sessions of the technology deployment despite clear relevance with the strategy's goals.

“These revelations show once again that the anti-racism commitments policing has undertaken through the race action plan are failing to be integrated into wider practice. Independent assessments have cautioned that new technologies are being implemented in a context where ethnic inequalities, inadequate oversight and poor data collection already persist.

“Any use of this technology must adhere to strict national standards, be independently scrutinised, and prove it reduces rather than exacerbates ethnic bias.”

Official Statement

A government representative stated: “The Home Office treat the conclusions of the report seriously and we have implemented changes. A new algorithm 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 ensuring public safety. 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 pursued without trained officers meticulously examining the output.”