British Law Enforcement Agencies Lobbied to Employ Biased Face Scanning Systems

Law enforcement agencies across the United Kingdom successfully lobbied to use a facial recognition system acknowledged as discriminatory against females, young people, and members of minority ethnic backgrounds, after complaining that a more accurate version generated a reduced number of potential suspects.

The Technology in Practice

UK forces utilize the national police database to conduct retrospective facial recognition searches. This procedure involves comparing a “probe image” of a suspect against a repository of over 19 million mugshots to identify possible hits.

Acknowledged Discrimination

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

“It prompts the question of whether facial recognition only becomes useful if users tolerate discrimination in ethnicity and gender. Operational ease is a weak argument for disregarding fundamental rights.”

Known Issue

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

Police bosses were notified of the system's bias in September 2024. The Home Office-commissioned laboratory study found the system was had a higher probability to produce false positives for photos of females, individuals of Black ethnicity, and those under 40 years old.

A Policy U-Turn

In reaction, the National Police Chiefs’ Council (NPCC) mandated that the confidence threshold required for potential matches be raised to a point where the disparity was significantly reduced.

However, this directive was reversed the following month following complaints from police that the modified technology was generating a lower number of “useful lines of inquiry”. Internal records indicate the higher threshold reduced the proportion of queries resulting in potential matches from 56% to a mere 14%.

Severe Disparities

Although the authorities declined to specify what setting is now in operation, the recent NPL study discovered the system could produce false positives for women of Black heritage nearly a hundred times more frequently than for white women at specific configurations.

The ministry stated on these findings: “Our evaluation identified that in a limited set of circumstances the algorithm is has a greater tendency to incorrectly include some population segments in its match reports.”

Balancing Utility and Fairness

Outlining the impact of the temporary raise to the system's accuracy setting, the police records state: “The change significantly reduces the effect of bias across legally safeguarded attributes of ethnicity, age and gender but had a substantially detrimental effect on police efficiency”. The papers further note that police units argued that “a once effective tactic now delivered outcomes of limited benefit”.

Broader Rollout Plans

Meanwhile, the government has opened a two-and-a-half-month public review on its proposals to expand the use of biometric scanning systems. Policing minister Sarah Jones has described the technology as the “most significant advance since genetic fingerprinting”.

Criticism from Advisors and Monitors

The chair of a police oversight board, head of the advisory panel for the national policing equality strategy, commented: “There was very little consideration in equality strategy sessions of the facial recognition rollout despite obvious cross-over with the strategy's goals.

“These revelations show yet again that the pledges to combat discrimination policing has made through the race action plan are failing to be integrated into wider practice. Our reports have warned that innovative tools are being implemented in a landscape where racial disparities, inadequate oversight and poor data collection already persist.

“All deployment of this technology must adhere to strict national standards, be independently scrutinised, and prove it diminishes rather than compounds racial disparity.”

Official Statement

A Home Office spokesperson stated: “We treat the findings of the study with utmost gravity and we have implemented changes. A updated software has been externally evaluated and acquired, which has demonstrated no measurable discrimination. It will be tested in the coming months and will be subject to evaluation.

“The foremost aim is protecting the public. This revolutionary tool will support police to apprehend and prosecute offenders. There is human involvement in every step of the process and no arrest or charge would be taken without trained officers carefully reviewing the results.”