British Police Forces Lobbied to Use Biased Facial Recognition Systems

Law enforcement agencies across the United Kingdom effectively campaigned to deploy a facial recognition system known to be discriminatory against women, young people, and members of ethnic minority groups, after complaining that a less biased version produced fewer investigative leads.

The Technology in Practice

UK forces use the police national database (PND) to conduct searches using historical face recognition. This procedure entails comparing a “probe image” of a person of interest against a repository of over 19 million custody photos to identify potential matches.

Admitted Bias

The UK interior ministry conceded last week that the system was biased. This admission followed a review by the government's National Physical Laboratory found it incorrectly matched people of Black and Asian heritage and women at much greater frequency than white men. The Home Office said it “took steps on the findings”.

“This raises the issue of whether this technology only becomes effective if users accept discrimination in race and sex. Convenience is a poor argument for disregarding fundamental rights.”

Long-Standing Problem

Official papers show that this discriminatory flaw has been recognized for more than a year. Furthermore, law enforcement argued to overturn an earlier ruling that was designed to address the problem.

Police bosses were informed of the system's bias in late 2024. The government-ordered NPL review found the system was had a higher probability to suggest false positives for photos of women, Black people, and those under 40 years old.

A Policy U-Turn

In response, the National Police Chiefs’ Council (NPCC) mandated that the confidence threshold required for possible hits be raised to a level where the disparity was greatly diminished.

However, this directive was overturned the next month following complaints from police that the adjusted system was generating fewer “investigative leads”. Internal records indicate the higher threshold cut the number of searches that yielded possible identifications from 56% to a mere 14%.

Severe Disparities

Although the authorities declined to specify what threshold is currently used, the latest NPL study found the system could generate false positives for Black women almost 100 times more often than for Caucasian women at certain settings.

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

Operational Effectiveness vs. Bias

Outlining the impact of the brief increase to the system's accuracy setting, the police records note: “This adjustment greatly lessens the effect of discrimination across protected characteristics of ethnicity, age and sex but had a significant negative impact on police efficiency”. The documents further note that police units complained that “a once effective tactic returned results of questionable value”.

Broader Rollout Plans

Meanwhile, the UK administration has launched a two-and-a-half-month consultation on its plans to widen 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

Abimbola Johnson, head of the advisory panel for the national policing equality strategy, said: “There was scant discussion through equality strategy sessions of the technology deployment despite clear relevance with the plan’s concerns.

“These revelations demonstrate once again that the pledges to combat discrimination policing has made through the equality initiative are failing to be integrated into wider practice. Our reports have cautioned that new technologies are being implemented in a landscape where ethnic inequalities, inadequate oversight and poor data collection already persist.

“All deployment of facial recognition must meet rigorous official guidelines, be independently scrutinised, and demonstrate it diminishes rather than compounds ethnic bias.”

Official Statement

A Home Office spokesperson said: “The Home Office treat the findings of the report with utmost gravity and we have already taken action. A updated software has been independently tested and procured, which has no statistically significant bias. It will be trialled early next year and will be undergo evaluation.

“Our priority is ensuring public safety. This revolutionary tool will support police to put criminals and rapists behind bars. There is human involvement in each stage of the process and no further action would be pursued without specialist personnel carefully reviewing the output.”