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Police forces across the United Kingdom successfully lobbied to deploy a facial recognition system known to be biased against females, youths, and individuals from ethnic minority groups, after complaining that a less biased version generated fewer investigative leads.

The Technology in Practice

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

Admitted Bias

The Home Office conceded last week that the technology was biased. This admission followed a study by the National Physical Laboratory (NPL) determined it incorrectly matched Black and Asian people and females at much greater frequency than Caucasian males. The Home Office said it “took steps on the findings”.

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

Long-Standing Problem

Internal documents reveal that this discriminatory flaw has been recognized for more than a year. Furthermore, law enforcement lobbied to reverse an earlier ruling that was intended to address the problem.

Senior officers were informed of the algorithmic discrimination in September 2024. The government-ordered NPL review found the system was had a higher probability to suggest incorrect matches for photos of women, individuals of Black ethnicity, and those under 40 years old.

A Reversed Decision

In response, the national police leadership body ordered that the accuracy setting required for potential matches be raised to a point where the disparity was significantly reduced.

However, this decision was overturned the following month after forces complained that the adjusted system was producing a lower number of “useful lines of inquiry”. Internal records show the higher threshold cut the proportion of searches that yielded possible identifications from 56% to a mere under 15%.

Profound Inequalities

Although the authorities refused to say what setting is currently used, the recent independent review discovered the system could produce false positives for Black women almost 100 times more frequently than for Caucasian women at certain settings.

The ministry stated on these findings: “The testing found that in a specific scenarios the algorithm is more likely to wrongly flag some demographic groups in its search results.”

Operational Effectiveness vs. Bias

Describing the effect of the temporary raise to the system's accuracy setting, the NPCC documents note: “This adjustment significantly reduces the effect of discrimination across protected characteristics of ethnicity, age and gender but had a substantially detrimental effect on operational effectiveness”. The papers add that forces complained that “a once effective tactic now delivered results of questionable value”.

Broader Rollout Plans

Meanwhile, the government has opened a ten-week consultation on its plans to widen the use of biometric scanning systems. Policing minister Sarah Jones has labeled the tool as the “most significant advance since genetic fingerprinting”.

Criticism from Advisors and Monitors

The chair of a police oversight board, head of the advisory panel for the police race action plan, said: “There was very little consideration through equality strategy sessions of the facial recognition rollout even with obvious cross-over with the plan’s concerns.

“This disclosure show once again that the anti-racism commitments policing has made through the race action plan are not being translated into wider practice. Independent assessments have warned that new technologies are being rolled out in a landscape where racial disparities, weak scrutiny and poor data collection continue to exist.

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

Home Office Response

A Home Office spokesperson said: “The Home Office takes the conclusions of the study seriously and we have implemented changes. A updated software has been independently tested and acquired, which has demonstrated no measurable discrimination. It will be trialled in the coming months and will be undergo further assessment.

“Our priority is protecting the public. This revolutionary tool will assist officers to apprehend and prosecute offenders. There is officer review in each stage of the process and no arrest or charge would be taken without specialist personnel carefully reviewing the output.”