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Police forces across the United Kingdom effectively campaigned to use a facial recognition system acknowledged as discriminatory against females, youths, and individuals from minority ethnic backgrounds, after complaining that a more accurate version generated fewer investigative leads.

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 person of interest against a repository of more than 19 million mugshots to find possible hits.

Acknowledged Discrimination

The UK interior ministry admitted last week that the technology was flawed. This acknowledgment followed a review by the government's National Physical Laboratory found it misidentified people of Black and Asian heritage and females at much greater frequency than white men. The Home Office said it “had acted on the findings”.

“This raises the issue of whether this technology only becomes useful if users tolerate discrimination in ethnicity and gender. Convenience is a poor argument for disregarding basic freedoms.”

Known Issue

Internal documents show that this bias has been recognized for more than a year. Furthermore, law enforcement lobbied to reverse an initial decision that was intended to mitigate the problem.

Senior officers were informed of the system's bias in September 2024. The Home Office-commissioned laboratory study concluded the system was more likely to suggest incorrect matches for photos of females, individuals of Black ethnicity, and those aged 40 and under.

A Policy U-Turn

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

However, this decision was overturned the next month following complaints from police that the modified technology was producing fewer “useful lines of inquiry”. Internal records show the higher threshold cut the proportion of queries resulting in potential matches from 56% to a just under 15%.

Severe Disparities

Although the Home Office and NPCC refused to say what setting is now in operation, the recent NPL study discovered the system could generate incorrect matches for women of Black heritage nearly a hundred times more frequently than for Caucasian women at certain settings.

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 match reports.”

Operational Effectiveness vs. Bias

Describing the impact of the brief increase to the system's accuracy setting, the NPCC documents state: “This adjustment significantly reduces the impact of discrimination across legally safeguarded attributes of ethnicity, age and sex but had a significant negative impact on police efficiency”. The documents further note that forces argued that “a previously useful tool returned outcomes of questionable value”.

Broader Rollout Plans

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

Criticism from Advisors and Monitors

The chair of a police oversight board, chair of the advisory panel for the national policing equality strategy, commented: “We observed very little consideration in equality strategy sessions of the facial recognition rollout even with obvious cross-over with the plan’s concerns.

“This disclosure demonstrate once again that the anti-racism commitments the police has made via the race action plan are not being translated into wider practice. Independent assessments have cautioned that innovative tools are being rolled out in a landscape where racial disparities, weak scrutiny and poor data collection already persist.

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

Home Office Response

A Home Office spokesperson stated: “The Home Office treat the conclusions of the report with utmost gravity and we have already taken action. A updated software has been externally evaluated and acquired, which has no statistically significant bias. It will be tested in the coming months and will be subject to evaluation.

“The foremost aim is protecting the public. This gamechanging technology will support police to put criminals and rapists behind bars. There is human involvement in every step of the procedure and no further action would be pursued without specialist personnel carefully reviewing the results.”