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Law enforcement agencies across the UK successfully lobbied to deploy a facial recognition system acknowledged as discriminatory against females, young people, and members of minority ethnic backgrounds, following complaints that a more accurate version produced fewer investigative leads.

How the System Works

British police utilize the national police database to carry out searches using historical face recognition. This procedure entails 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 biased. This admission followed a study by the government's National Physical Laboratory determined it incorrectly matched Black and Asian people and women at significantly higher rates than white men. The ministry said it “had acted on the findings”.

“It prompts the question of whether this technology only becomes effective if users tolerate biases in race and sex. Operational ease is a weak argument for overriding basic freedoms.”

Long-Standing Problem

Internal documents show that this discriminatory flaw has been recognized for more than a year. Furthermore, law enforcement argued to overturn an initial decision that was intended to mitigate the problem.

Senior officers were notified of the algorithmic discrimination in late 2024. The government-ordered NPL review concluded the system was had a higher probability to suggest false positives for photos of women, individuals of Black ethnicity, and those aged 40 and under.

A Policy U-Turn

In response, the National Police Chiefs’ Council (NPCC) mandated that the confidence threshold required for potential matches be increased to a point where the bias was greatly diminished.

However, this directive was overturned the next month following complaints from police that the adjusted system was producing fewer “investigative leads”. Internal records show the higher threshold reduced the proportion of searches resulting in possible identifications from over half to a mere 14%.

Profound Inequalities

Although the Home Office and NPCC declined to specify what setting is now in operation, the recent NPL study found the system could produce incorrect matches for women of Black heritage nearly a hundred times more often than for Caucasian women at certain settings.

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

Operational Effectiveness vs. Bias

Describing the impact of the brief increase to the system's confidence threshold, the police records note: “This adjustment significantly reduces the effect of bias across legally safeguarded attributes of race, generation and sex but had a significant negative impact on police efficiency”. The papers add that forces argued that “a once effective tactic now delivered results of questionable value”.

Broader Rollout Plans

Meanwhile, the government has opened 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, chair of the advisory panel for the national policing equality strategy, said: “We observed scant discussion in equality strategy sessions of the technology deployment despite clear relevance with the strategy's goals.

“This disclosure demonstrate once again that the pledges to combat discrimination the police has undertaken through the race action plan are not being translated into broader operations. Independent assessments have warned that new technologies are being rolled out in a context where ethnic inequalities, inadequate oversight and poor data collection already persist.

“Any use of this technology must meet strict national standards, be subject to external review, and demonstrate it diminishes rather than compounds racial disparity.”

Official Statement

A government representative said: “We takes the conclusions of the study seriously and we have implemented changes. 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 further assessment.

“The foremost aim is protecting the public. This gamechanging technology will support police to apprehend and prosecute offenders. There is officer review in each stage of the process and no arrest or charge would be pursued without specialist personnel carefully reviewing the results.”