British Law Enforcement Agencies Lobbied to Employ Discriminatory Facial Recognition Systems

Police forces across the UK effectively campaigned to deploy a face scanning system acknowledged as discriminatory against women, young people, and members of ethnic minority groups, after complaining that a more accurate version generated fewer investigative leads.

The Technology in Practice

British police use the national police database to carry out searches using historical face recognition. This procedure involves comparing a “probe image” of a person of interest against a database of more than 19 million custody photos to identify potential matches.

Admitted Bias

The Home Office admitted last week that the technology was flawed. This admission followed a review by the government's National Physical Laboratory found it incorrectly matched people of Black and Asian heritage and females at much greater frequency than white men. The Home Office said it “had acted on the findings”.

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

Long-Standing Problem

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

Senior officers were informed of the system's bias in late 2024. The government-ordered laboratory study concluded the system was more likely to produce incorrect matches for images depicting females, individuals of Black ethnicity, and those under 40 years old.

A Reversed Decision

In response, the national police leadership body mandated that the confidence threshold required for possible hits be increased to a point where the disparity was significantly reduced.

However, this decision was overturned the following month following complaints from police that the adjusted system was producing a lower number of “useful lines of inquiry”. NPCC documents show the stricter setting cut the proportion of queries resulting in possible identifications from 56% to a just under 15%.

Severe Disparities

Although the authorities declined to specify what setting is currently used, the recent NPL study discovered the system could produce false positives for Black women almost 100 times more often than for white women at certain settings.

The Home Office stated on these results: “Our evaluation identified that in a limited set of circumstances the software is has a greater tendency to wrongly flag some demographic groups in its search results.”

Operational Effectiveness vs. Bias

Outlining the impact of the brief increase to the system's accuracy setting, the police records state: “The change greatly lessens the impact of discrimination across legally safeguarded attributes of ethnicity, generation and gender but had a substantially detrimental effect on operational effectiveness”. The papers add that police units complained that “a once effective tactic now delivered results of limited benefit”.

Broader Rollout Plans

Meanwhile, the government has launched a two-and-a-half-month consultation on its plans to widen the use of biometric scanning systems. Policing minister Sarah Jones has labeled the technology as the “biggest breakthrough since genetic fingerprinting”.

Criticism from Advisors and Monitors

The chair of a police oversight board, head of the independent scrutiny and oversight board for the national policing equality strategy, commented: “We observed scant consideration in equality strategy sessions of the technology deployment despite obvious cross-over with the strategy's goals.

“This disclosure demonstrate yet again that the pledges to combat discrimination policing has undertaken via the race action plan are failing to be integrated into broader operations. Our reports have cautioned that innovative tools are being rolled out in a landscape where racial disparities, weak scrutiny and poor data collection continue to exist.

“Any use of facial recognition must adhere to strict national standards, be subject to external review, and demonstrate it diminishes rather than compounds racial disparity.”

Home Office Response

A Home Office spokesperson said: “The Home Office takes the conclusions of the study with utmost gravity and we have implemented changes. A updated software has been independently tested and procured, which has no statistically significant bias. It will be tested early next year and will be subject to evaluation.

“The foremost aim is protecting the public. This gamechanging technology will assist police to apprehend and prosecute offenders. There is human involvement in each stage of the procedure and no further action would be taken without specialist personnel meticulously examining the output.”