UK Law Enforcement Agencies Lobbied to Use Discriminatory Face Scanning Systems

Law enforcement agencies across the UK effectively campaigned to deploy a face scanning system acknowledged as discriminatory against females, youths, and members of ethnic minority groups, after complaining that a less biased version generated fewer potential suspects.

The Technology in Practice

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

Admitted Bias

The UK interior ministry admitted last week that the technology was flawed. This admission came after a review by the government's National Physical Laboratory found it incorrectly matched people of Black and Asian heritage and women at significantly higher rates than white men. The Home Office said it “had acted on the findings”.

“This raises the question of whether facial recognition only becomes useful if users accept biases in race and gender. Convenience is a weak argument for overriding fundamental rights.”

Known Issue

Internal documents show that this bias has been known about for more than a year. Furthermore, law enforcement lobbied to reverse an earlier ruling that was intended to address the problem.

Police bosses were notified of the system's bias in late 2024. The Home Office-commissioned NPL review found the system was had a higher probability to suggest false positives for images depicting women, Black people, and those aged 40 and under.

A Policy U-Turn

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 directive was reversed the next month after forces complained that the modified technology was generating a lower number of “investigative leads”. NPCC documents indicate the stricter setting reduced the proportion of searches that yielded possible identifications from 56% to a mere under 15%.

Profound Inequalities

Although the authorities declined to specify what threshold is currently used, the latest independent review discovered the system could generate false positives for women of Black heritage almost 100 times more frequently than for white women at certain settings.

The Home Office stated on these results: “Our evaluation found that in a specific scenarios the algorithm is has a greater tendency to incorrectly include some population segments in its search results.”

Operational Effectiveness vs. Bias

Describing the effect of the brief increase to the system's confidence threshold, the police records note: “This adjustment greatly lessens the impact of discrimination across protected characteristics of race, generation and gender but had a substantially detrimental effect on police efficiency”. The documents add that forces argued that “a previously useful tool returned results of limited benefit”.

Wider Implementation Proposals

Meanwhile, the UK administration has opened a ten-week consultation on its plans to widen the use of biometric scanning systems. The minister for police Sarah Jones has labeled the technology as the “biggest breakthrough since DNA matching”.

Expert and Oversight Concerns

Abimbola Johnson, head of the independent scrutiny and oversight board for the police race action plan, said: “There was scant discussion in race action plan meetings of the technology deployment even with clear relevance with the plan’s concerns.

“These revelations demonstrate once again that the anti-racism commitments policing has made through the equality initiative are failing to be integrated into wider practice. Our reports have warned that new technologies are being implemented in a context where ethnic inequalities, inadequate oversight and faulty information gathering already persist.

“All deployment of this technology must meet rigorous official guidelines, be subject to external review, and demonstrate it reduces rather than compounds racial disparity.”

Official Statement

A government representative 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 no statistically significant bias. It will be trialled early next year and will be subject to evaluation.

“Our priority is ensuring public safety. This revolutionary tool will support police to put criminals and rapists behind bars. There is human involvement in each stage of the process and no further action would be pursued without trained officers meticulously examining the output.”