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Law enforcement agencies across the United Kingdom effectively campaigned to use a facial recognition system known to be discriminatory against women, youths, and individuals from ethnic minority groups, after complaining that a less biased version produced fewer potential suspects.

How the System Works

British police use the national police database to carry out searches using historical face recognition. This process entails comparing a reference photograph of a suspect against a repository of more than 19 million mugshots to find possible hits.

Acknowledged Discrimination

The UK interior ministry admitted last week that the system was flawed. This admission came after a review by the government's National Physical Laboratory found it misidentified people of Black and Asian heritage and females at significantly higher rates than Caucasian males. The ministry said it “took steps on the findings”.

“It prompts the issue of whether facial recognition only becomes effective if users accept biases in race and gender. Convenience is a poor argument for overriding basic freedoms.”

Long-Standing Problem

Official papers reveal that this bias has been known about for more than a year. Furthermore, police forces argued to overturn an initial decision that was intended to address the problem.

Senior officers were informed of the system's bias in September 2024. The Home Office-commissioned NPL review concluded the system was more likely to produce false positives for images depicting females, Black people, and those aged 40 and under.

A Policy U-Turn

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

However, this decision was overturned the next month after forces complained that the adjusted system was generating fewer “investigative leads”. NPCC documents show the higher threshold cut the number of searches that yielded potential matches from over half to a mere under 15%.

Profound Inequalities

Although the Home Office and NPCC declined to specify what setting is now in operation, the latest NPL study discovered the system could produce false positives for Black women nearly a hundred times more often than for Caucasian women at certain settings.

The ministry commented on these results: “The testing identified that in a limited set of circumstances the software is has a greater tendency to incorrectly include some population segments in its match reports.”

Operational Effectiveness vs. Bias

Describing the effect of the brief increase to the system's confidence threshold, the NPCC documents note: “This adjustment significantly reduces the effect of bias across legally safeguarded attributes of race, age and sex but had a significant negative impact on operational effectiveness”. The papers further note that police units complained that “a once effective tactic now delivered outcomes of limited benefit”.

Wider Implementation Proposals

Meanwhile, the government has launched a two-and-a-half-month public review on its proposals to widen the use of biometric scanning systems. Policing minister Sarah Jones has described the tool as the “biggest breakthrough since genetic fingerprinting”.

Expert and Oversight Concerns

The chair of a police oversight board, chair of the independent scrutiny and oversight board for the police race action plan, said: “There was scant consideration in race action plan meetings of the technology deployment despite clear relevance with the plan’s concerns.

“These revelations show 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 warned that innovative tools are being implemented in a context where ethnic inequalities, inadequate oversight and poor data collection continue to exist.

“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 Home Office spokesperson stated: “The Home Office takes the findings of the study seriously and we have already taken action. 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 evaluation.

“Our priority is protecting the public. This revolutionary tool will assist police to put criminals and rapists behind bars. There is officer review in every step of the process and no arrest or charge would be taken without trained officers meticulously examining the output.”