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Police forces across the UK successfully lobbied to deploy a facial recognition system acknowledged as biased against females, youths, and members of ethnic minority groups, after complaining that a more accurate version produced fewer potential suspects.

The Technology in Practice

British police utilize the police national database (PND) to carry out searches using historical face recognition. This process entails comparing a “probe image” of a suspect against a database of over 19 million mugshots to find possible hits.

Admitted Bias

The Home Office admitted last week that the system was biased. This acknowledgment followed a study by the government's National Physical Laboratory determined it incorrectly matched people of Black and Asian heritage and women at much greater frequency than white men. The Home Office stated it “had acted on the findings”.

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

Long-Standing Problem

Internal documents show that this discriminatory flaw has been recognized for more than a year. Furthermore, law enforcement lobbied to reverse an initial decision that was designed to address the problem.

Senior officers were notified of the algorithmic discrimination in September 2024. The Home Office-commissioned NPL review found the system was had a higher probability to produce false positives for photos of females, individuals of Black ethnicity, and those aged 40 and under.

A Reversed Decision

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

However, this directive was overturned the following month after forces complained that the adjusted system was producing fewer “investigative leads”. NPCC documents indicate the stricter setting reduced the proportion of queries resulting in possible identifications from over half to a just 14%.

Profound Inequalities

Although the authorities refused to say what setting is now in operation, the recent independent review found the system could generate incorrect matches 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 limited set of circumstances 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 accuracy setting, the NPCC documents state: “The change significantly reduces the effect of bias across legally safeguarded attributes of race, generation and sex but had a substantially detrimental effect on operational effectiveness”. The documents further note that police units argued that “a previously useful tool returned results of questionable value”.

Wider Implementation Proposals

Meanwhile, the government has opened a ten-week public review on its proposals to widen the use of facial recognition technology. Policing minister the relevant minister has labeled the tool as the “biggest breakthrough since genetic fingerprinting”.

Expert and Oversight Concerns

The chair of a police oversight board, head of the advisory panel for the police race action plan, commented: “We observed scant discussion through equality strategy sessions of the facial recognition rollout even with obvious cross-over with the plan’s concerns.

“These revelations demonstrate once again that the anti-racism commitments the police has undertaken via the race action plan are failing to be integrated into wider practice. Our reports have cautioned that innovative tools are being rolled out in a landscape where ethnic inequalities, weak scrutiny and poor data collection already persist.

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

Official Statement

A government representative said: “We treat the conclusions of the report with utmost gravity and we have already taken action. A updated software has been externally evaluated and procured, which has demonstrated no measurable discrimination. It will be tested early next year and will be subject to further assessment.

“The foremost aim is protecting the public. This revolutionary tool will assist officers to put criminals and rapists behind bars. There is human involvement in every step of the process and no further action would be taken without specialist personnel meticulously examining the results.”