British Law Enforcement Agencies Lobbied to Use Discriminatory Face Scanning Systems

Police forces across the United Kingdom successfully lobbied to use a face scanning system acknowledged as discriminatory against women, youths, and members of minority ethnic backgrounds, following complaints that a more accurate version generated fewer investigative leads.

How the System Works

British police utilize the police national database (PND) to conduct searches using historical face recognition. This procedure involves comparing a reference photograph of a person of interest against a repository of over 19 million mugshots to find possible hits.

Admitted Bias

The UK interior ministry admitted last week that the system was flawed. This acknowledgment came after a study by the government's National Physical Laboratory determined it incorrectly matched people of Black and Asian heritage and women at significantly higher rates than white men. The ministry stated it “took steps on the findings”.

“It prompts the question of whether this technology only becomes useful if users accept biases in race and gender. Operational ease is a weak argument for overriding fundamental rights.”

Long-Standing Problem

Official papers reveal that this bias has been recognized for more than a year. Furthermore, police forces lobbied to reverse an earlier ruling that was intended to mitigate the problem.

Senior officers were informed of the algorithmic discrimination in late 2024. The Home Office-commissioned NPL review concluded the system was had a higher probability to suggest incorrect matches for images depicting women, Black people, and those aged 40 and under.

A Reversed Decision

In response, the National Police Chiefs’ Council (NPCC) mandated that the accuracy setting required for potential matches be increased to a level where the disparity was significantly reduced.

However, this directive 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 higher threshold cut the number of searches that yielded possible identifications from 56% to a mere under 15%.

Profound Inequalities

Although the Home Office and NPCC declined to specify what threshold is currently used, the recent independent review found the system could generate false positives for Black women almost 100 times more frequently than for Caucasian women at certain settings.

The ministry commented on these results: “The testing identified that in a specific scenarios the algorithm is has a greater tendency to wrongly flag some demographic groups in its match reports.”

Operational Effectiveness vs. Bias

Outlining the effect of the brief increase to the system's confidence threshold, the police records note: “This adjustment significantly reduces the impact of bias across legally safeguarded attributes of race, age and sex but had a significant negative impact on police efficiency”. The papers add that police units argued that “a previously useful tool now delivered outcomes of limited benefit”.

Broader Rollout Plans

Meanwhile, the government has opened a ten-week public review on its proposals to widen the use of biometric scanning systems. Policing minister Sarah Jones has described the tool as the “most significant advance since DNA matching”.

Expert and Oversight Concerns

The chair of a police oversight board, head of the advisory panel for the police race action plan, commented: “We observed very little discussion through race action plan meetings of the facial recognition rollout even with clear relevance with the plan’s concerns.

“This disclosure demonstrate yet again that the pledges to combat discrimination the police has made through the equality initiative are not being translated into broader operations. Our reports have cautioned that new technologies are being rolled out in a landscape where ethnic inequalities, weak scrutiny and poor data collection continue to exist.

“All deployment of facial recognition must meet strict national standards, be independently scrutinised, and prove it diminishes rather than compounds racial disparity.”

Official Statement

A Home Office spokesperson said: “The Home Office treat the findings of the report seriously and we have implemented changes. A updated software has been externally evaluated and procured, which has no statistically significant bias. It will be trialled early next year and will be undergo further assessment.

“Our priority is ensuring public safety. This gamechanging technology will assist police to apprehend and prosecute offenders. There is officer review in every step of the procedure and no arrest or charge would be pursued without specialist personnel meticulously examining the output.”