UK Law Enforcement Agencies Lobbied to Employ Discriminatory Face Scanning Technology

Police forces across the UK effectively campaigned to use a facial recognition system known to be discriminatory against females, youths, and members of ethnic minority groups, following complaints that a less biased version generated a reduced number of potential suspects.

How the System Works

British police utilize the national police database to carry out searches using historical face recognition. This procedure involves matching a reference photograph of a suspect against a repository of over 19 million custody photos to find potential matches.

Admitted Bias

The Home Office admitted last week that the technology was biased. This admission came after a study by the National Physical Laboratory (NPL) found it misidentified 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 issue of whether this technology only becomes useful if users accept discrimination in race and gender. Convenience is a weak argument for overriding fundamental rights.”

Known Issue

Internal documents show that this bias has been known about for over twelve months. Furthermore, police forces argued to overturn an initial decision that was intended to mitigate the problem.

Police bosses were informed of the system's bias in September 2024. The government-ordered NPL review concluded the system was more likely to produce incorrect matches for images depicting females, individuals of Black ethnicity, and those aged 40 and under.

A Policy U-Turn

In response, the National Police Chiefs’ Council (NPCC) ordered that the confidence threshold required for potential matches be increased to a level where the disparity was significantly reduced.

However, this decision was reversed the following month following complaints from police that the adjusted system was generating a lower number of “investigative leads”. Internal records indicate the stricter setting reduced the number of queries resulting in possible identifications from over half to a mere under 15%.

Severe Disparities

Although the Home Office and NPCC declined to specify what setting is now in operation, the recent independent review discovered the system could generate incorrect matches for women of Black heritage nearly a hundred times more often than for white women at specific configurations.

The ministry stated on these results: “Our evaluation identified that in a limited set of circumstances the software is has a greater tendency to wrongly flag some population segments in its search results.”

Balancing Utility and Fairness

Describing the impact of the brief increase to the system's accuracy setting, the police records note: “The change greatly lessens the effect of discrimination across protected characteristics of ethnicity, generation and sex 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”.

Broader Rollout Plans

Meanwhile, the UK administration has launched a two-and-a-half-month consultation on its plans to expand the use of facial recognition technology. Policing minister Sarah Jones has described the technology as the “most significant advance since DNA matching”.

Expert and Oversight Concerns

The chair of a police oversight board, chair of the advisory panel for the police race action plan, said: “We observed very little discussion through race action plan meetings of the technology deployment even with clear relevance with the strategy's goals.

“This disclosure demonstrate once again that the anti-racism commitments the police has undertaken through the equality initiative are failing to be integrated into broader operations. Our reports have cautioned that new technologies are being implemented in a landscape where racial disparities, weak scrutiny and faulty information gathering continue to exist.

“All deployment 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 said: “The Home Office takes the findings of the report with utmost gravity and we have implemented changes. A updated software has been independently tested and procured, which has demonstrated no measurable discrimination. It will be tested early next year and will be subject to further assessment.

“Our priority is ensuring public safety. 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 taken without specialist personnel carefully reviewing the output.”