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Law enforcement agencies across the UK successfully lobbied to deploy a facial recognition system acknowledged as biased against females, youths, and members of minority ethnic backgrounds, following complaints that a more accurate version produced a reduced number of potential suspects.

How the System Works

UK forces utilize the national police database to carry out retrospective facial recognition searches. This process entails matching a reference photograph of a suspect against a repository of more than 19 million mugshots to find possible hits.

Admitted Bias

The Home Office admitted last week that the system was biased. This admission came after a study by the government's National Physical Laboratory determined it misidentified Black and Asian people and females at significantly higher rates than white men. The Home Office said it “had acted on the findings”.

“It prompts the issue of whether this technology only becomes useful if users accept biases in ethnicity and sex. Operational ease is a weak argument for disregarding basic freedoms.”

Long-Standing Problem

Official papers reveal that this discriminatory flaw has been recognized for more than a year. Furthermore, police forces lobbied to reverse an initial decision that was intended to address the problem.

Senior officers were informed of the system's bias in September 2024. The government-ordered laboratory study concluded the system was had a higher probability to produce false positives for photos of women, Black people, and those aged 40 and under.

A Policy U-Turn

In reaction, the national police leadership body ordered that the accuracy setting required for potential matches be raised to a point where the bias was greatly diminished.

However, this directive was overturned the next month following complaints from police that the adjusted system was producing fewer “useful lines of inquiry”. Internal records show the stricter setting reduced the number of searches that yielded potential matches from over half to a just 14%.

Profound Inequalities

Although the Home Office and NPCC refused to say what threshold is now in operation, the recent independent review discovered the system could generate false positives for Black women almost 100 times more frequently than for white women at specific configurations.

The ministry commented on these findings: “Our evaluation identified that in a specific scenarios the software is more likely to wrongly flag some demographic groups in its search results.”

Operational Effectiveness vs. Bias

Outlining the impact of the brief increase to the system's confidence threshold, the NPCC documents state: “The change significantly reduces the impact of discrimination across legally safeguarded attributes of ethnicity, generation and sex but had a substantially detrimental effect on operational effectiveness”. The documents add that forces complained that “a once effective tactic returned results of limited benefit”.

Broader Rollout Plans

Meanwhile, the government has opened a two-and-a-half-month consultation on its proposals to expand the use of facial recognition technology. Policing minister Sarah Jones has labeled the tool as the “most significant advance since genetic fingerprinting”.

Expert and Oversight Concerns

The chair of a police oversight board, head of the advisory panel for the national policing equality strategy, said: “There was very little consideration through equality strategy sessions of the facial recognition rollout even with clear relevance with the strategy's goals.

“This disclosure demonstrate yet again that the anti-racism commitments the police has made through the equality initiative are failing to be integrated into broader operations. Independent assessments have warned that innovative tools are being implemented in a landscape where ethnic inequalities, weak scrutiny and faulty information gathering continue to exist.

“All deployment of this technology must adhere to rigorous official guidelines, be subject to external review, and demonstrate it reduces rather than exacerbates ethnic bias.”

Home Office Response

A Home Office spokesperson said: “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 in the coming months and will be subject to evaluation.

“Our priority is ensuring public safety. This revolutionary tool will support officers to apprehend and prosecute offenders. There is human involvement in every step of the procedure and no further action would be pursued without trained officers carefully reviewing the results.”