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Law enforcement agencies across the UK successfully lobbied to use a facial recognition system acknowledged as biased against females, young people, and individuals from ethnic minority groups, following complaints that a more accurate version produced fewer potential suspects.

The Technology in Practice

UK forces utilize the police national database (PND) to carry out searches using historical face recognition. This process entails comparing a reference photograph of a person of interest against a database of more than 19 million custody photos to find possible hits.

Acknowledged Discrimination

The Home Office conceded last week that the technology was biased. This acknowledgment came after a review by the National Physical Laboratory (NPL) determined it misidentified Black and Asian people and women at much greater frequency than white men. The ministry said it “had acted on the findings”.

“It prompts the question of whether this technology only becomes effective if users tolerate discrimination in ethnicity and sex. Operational ease is a weak argument for overriding fundamental rights.”

Known Issue

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

Police bosses were notified of the system's bias in late 2024. The government-ordered NPL review found the system was had a higher probability to suggest false positives for photos of females, Black people, and those under 40 years old.

A Reversed Decision

In response, the national police leadership body mandated that the confidence threshold required for potential matches be raised to a level where the bias was greatly diminished.

However, this directive was overturned the next month after forces complained that the adjusted system was generating a lower number of “useful lines of inquiry”. Internal records indicate the higher threshold reduced the number of queries resulting in possible identifications from 56% to a mere 14%.

Severe Disparities

Although the authorities refused to say what threshold is currently used, the latest NPL study discovered the system could generate false positives for women of Black heritage almost 100 times more often than for Caucasian women at specific configurations.

The ministry stated on these results: “Our evaluation found that in a limited set of circumstances the software is more likely to wrongly flag some demographic groups in its search results.”

Operational Effectiveness vs. Bias

Outlining the impact of the temporary raise to the system's confidence threshold, the NPCC documents note: “This adjustment greatly lessens the effect of discrimination across protected characteristics of race, age and gender but had a substantially detrimental effect on police efficiency”. The papers add that forces complained that “a previously useful tool now delivered results of questionable value”.

Wider Implementation Proposals

Meanwhile, the government has launched a two-and-a-half-month public review on its plans to widen the use of biometric scanning systems. The minister for police Sarah Jones has labeled the technology as the “most significant advance since genetic fingerprinting”.

Criticism from Advisors and Monitors

Abimbola Johnson, chair of the advisory panel for the national policing equality strategy, commented: “There was very little discussion in equality strategy sessions of the facial recognition rollout even with clear relevance with the strategy's goals.

“These revelations show yet again that the pledges to combat discrimination the police has undertaken through the race action plan are failing to be integrated into wider practice. Independent assessments have warned that new technologies are being implemented in a landscape where ethnic inequalities, weak scrutiny and poor data collection already persist.

“Any use of facial recognition must adhere to strict national standards, be independently scrutinised, and prove it reduces rather than compounds ethnic bias.”

Official Statement

A government representative stated: “We treat the conclusions of the report with utmost gravity 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 undergo evaluation.

“The foremost aim is ensuring public safety. This gamechanging technology will support police to apprehend and prosecute offenders. There is human involvement in each stage of the process and no arrest or charge would be pursued without trained officers meticulously examining the output.”