British Law Enforcement Agencies Lobbied to Use Discriminatory Face Scanning Systems

Law enforcement agencies across the United Kingdom effectively campaigned to use a face scanning system acknowledged as discriminatory against females, young people, and individuals from ethnic minority groups, after complaining that a more accurate version generated fewer potential suspects.

The Technology in Practice

British police use 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 more than 19 million custody photos to identify potential matches.

Admitted Bias

The Home Office conceded last week that the technology was biased. This admission followed a study by the government's National Physical Laboratory determined it incorrectly matched Black and Asian people and women at much greater frequency than Caucasian males. The Home Office said it “had acted on the findings”.

“It prompts the issue of whether this technology only becomes effective if users accept discrimination in race and gender. Convenience is a weak argument for overriding basic freedoms.”

Known Issue

Official papers reveal that this discriminatory flaw has been recognized for more than a year. Furthermore, law enforcement lobbied to reverse an initial decision that was intended to mitigate the problem.

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

A Policy U-Turn

In reaction, the national police leadership body ordered that the accuracy setting required for possible hits be increased to a level where the bias was significantly reduced.

However, this directive was reversed the next month following complaints from police that the modified technology was producing a lower number of “investigative leads”. Internal records show the stricter setting reduced the number of queries that yielded possible identifications from over half to a mere 14%.

Profound Inequalities

Although the Home Office and NPCC declined to specify what setting is currently used, the latest NPL study found the system could produce false positives for Black women nearly a hundred times more often than for Caucasian women at specific configurations.

The ministry commented on these results: “The testing identified that in a limited set of circumstances the algorithm is has a greater tendency to wrongly flag some population segments in its search results.”

Operational Effectiveness vs. Bias

Outlining the effect of the brief increase to the system's accuracy setting, the police records state: “This adjustment greatly lessens the effect of discrimination across legally safeguarded attributes of race, generation and gender but had a substantially detrimental effect on operational effectiveness”. The documents add that forces argued that “a previously useful tool returned outcomes of limited benefit”.

Wider Implementation Proposals

Meanwhile, the government has launched a two-and-a-half-month public review on its proposals to widen the use of facial recognition technology. The minister for police Sarah Jones has described the technology as the “biggest breakthrough since DNA matching”.

Expert and Oversight Concerns

The chair of a police oversight board, chair of the independent scrutiny and oversight board for the police race action plan, said: “We observed scant consideration in equality strategy sessions of the technology deployment 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 equality initiative are not being translated into broader operations. Independent assessments have warned that innovative tools are being rolled out in a context where racial disparities, weak scrutiny and poor data collection continue to exist.

“All deployment of this technology must adhere to strict national standards, be independently scrutinised, and demonstrate it reduces rather than exacerbates ethnic bias.”

Official Statement

A government representative said: “The Home Office treat the findings of the report seriously and we have implemented changes. A new algorithm has been externally evaluated and procured, which has demonstrated no measurable discrimination. It will be trialled in the coming months and will be subject to evaluation.

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