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Police forces across the UK successfully lobbied to use a facial recognition system acknowledged as discriminatory against women, youths, and individuals from ethnic minority groups, following complaints that a more accurate version generated a reduced number of investigative leads.

How the System Works

UK forces utilize the national police database to carry out searches using historical face recognition. This procedure entails matching a reference photograph of a suspect against a database of more than 19 million custody photos to identify possible hits.

Admitted Bias

The UK interior ministry admitted last week that the system was flawed. This acknowledgment came after a study by the government's National Physical Laboratory determined it incorrectly matched Black and Asian people and females at much greater frequency than Caucasian males. The ministry stated it “had acted on the findings”.

“This raises the question of whether facial recognition only becomes useful if users tolerate biases in ethnicity and gender. Convenience is a weak argument for overriding basic freedoms.”

Known Issue

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

Senior officers were notified of the system's bias in late 2024. The Home Office-commissioned laboratory study found the system was had a higher probability to produce incorrect matches for photos of females, Black people, and those aged 40 and under.

A Reversed Decision

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

However, this decision was overturned the following month after forces complained that the adjusted system was generating a lower number of “useful lines of inquiry”. Internal records show the higher threshold reduced the proportion of searches that yielded possible identifications from 56% to a just 14%.

Profound Inequalities

Although the Home Office and NPCC refused to say what setting is currently used, the latest NPL study found the system could produce incorrect matches for women of Black heritage almost 100 times more frequently than for white women at certain settings.

The ministry commented 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.”

Balancing Utility and Fairness

Describing the effect of the brief increase to the system's confidence threshold, the police records state: “This adjustment significantly reduces the effect of bias across protected characteristics of ethnicity, age and gender but had a significant negative impact on operational effectiveness”. The documents add that forces complained that “a previously useful tool now delivered outcomes of questionable value”.

Wider Implementation Proposals

Meanwhile, the government has launched a two-and-a-half-month public review on its proposals to expand the use of facial recognition technology. Policing minister the relevant minister has described the tool as the “most significant advance since genetic fingerprinting”.

Expert and Oversight Concerns

Abimbola Johnson, chair of the independent scrutiny and oversight board for the police race action plan, commented: “There was scant discussion in race action plan meetings of the technology deployment even with clear relevance with the strategy's goals.

“These revelations demonstrate yet again that the anti-racism commitments the police has undertaken through the equality initiative are not being translated into broader operations. Independent assessments have cautioned that innovative tools are being implemented in a landscape where ethnic inequalities, weak scrutiny and faulty information gathering already persist.

“Any use of facial recognition must meet strict national standards, be subject to external review, and prove it reduces rather than compounds ethnic bias.”

Home Office Response

A government representative stated: “The Home Office takes the findings of the study seriously and we have already taken action. A updated software has been externally evaluated and acquired, which has demonstrated no measurable discrimination. It will be trialled early next year and will be undergo further assessment.

“The foremost aim is ensuring public safety. This gamechanging technology will support police to apprehend and prosecute offenders. There is officer review in each stage of the process and no further action would be pursued without specialist personnel carefully reviewing the output.”