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Law enforcement agencies across the UK successfully lobbied to use a facial recognition system acknowledged as discriminatory against females, youths, and members of ethnic minority groups, after complaining that a less biased version generated a reduced number of potential suspects.

How the System Works

British police utilize the police national database (PND) to carry out searches using historical face recognition. This process involves comparing a reference photograph of a suspect against a database of over 19 million mugshots to identify possible hits.

Admitted Bias

The Home Office admitted last week that the technology was flawed. This acknowledgment came after a study by the government's National Physical Laboratory found it misidentified people of Black and Asian heritage and women at much greater frequency than Caucasian males. The ministry stated it “had acted on the findings”.

“This raises the issue of whether facial recognition only becomes useful if users tolerate discrimination in ethnicity and gender. Operational ease is a poor argument for overriding fundamental rights.”

Long-Standing Problem

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

Police bosses were informed of the system's bias in September 2024. The government-ordered laboratory study concluded the system was more likely to produce incorrect matches for photos of females, Black people, and those under 40 years old.

A Reversed Decision

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

However, this directive was reversed the following month following complaints from police that the modified technology was producing fewer “investigative leads”. NPCC documents indicate the higher threshold cut the number of searches that yielded potential matches from over half to a mere 14%.

Profound Inequalities

Although the Home Office and NPCC refused to say what threshold is now in operation, the recent independent review found the system could generate false positives for women of Black heritage nearly a hundred times more frequently than for white women at specific configurations.

The ministry stated on these findings: “The testing found 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 temporary raise to the system's accuracy setting, the NPCC documents state: “This adjustment significantly reduces the impact of discrimination across protected characteristics of race, generation and gender but had a substantially detrimental effect on police efficiency”. The documents further note that police units complained that “a previously useful tool returned results of questionable value”.

Wider Implementation Proposals

Meanwhile, the UK administration has launched a two-and-a-half-month consultation on its proposals to expand the use of facial recognition technology. The minister for police Sarah Jones has labeled the tool as the “biggest breakthrough since DNA matching”.

Expert and Oversight Concerns

Abimbola Johnson, head of the independent scrutiny and oversight board for the national policing equality strategy, said: “There was very little consideration through race action plan meetings of the technology deployment even with clear relevance with the plan’s concerns.

“These revelations demonstrate once again that the pledges to combat discrimination the police has made through the equality initiative are failing to be integrated into broader operations. Independent assessments have warned that new technologies are being implemented in a landscape where racial disparities, inadequate oversight and poor data collection already persist.

“Any use of this technology must adhere to strict national standards, be subject to external review, and prove it reduces rather than exacerbates ethnic bias.”

Home Office Response

A Home Office spokesperson said: “We takes the conclusions of the report seriously and we have already taken action. A new algorithm has been externally evaluated and acquired, which has no statistically significant bias. It will be trialled early next year and will be undergo 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 each stage of the process and no further action would be pursued without trained officers carefully reviewing the results.”