British Law Enforcement Agencies Campaign to Employ Discriminatory Face Scanning Technology

Law enforcement agencies across the UK successfully lobbied to deploy a facial recognition system acknowledged as discriminatory against women, young people, and members of ethnic minority groups, following complaints that a less biased version generated fewer investigative leads.

The Technology in Practice

British police use the national police database to conduct retrospective facial recognition searches. This procedure involves comparing a “probe image” of a person of interest against a database of more than 19 million custody photos to identify possible hits.

Admitted Bias

The Home Office admitted last week that the technology was biased. This acknowledgment came after a review by the government's National Physical Laboratory found it misidentified Black and Asian people and females at significantly higher rates than white men. The Home Office said it “took steps on the findings”.

“It prompts the question of whether this technology only becomes effective if users accept biases in race and sex. Operational ease is a poor argument for disregarding fundamental rights.”

Known Issue

Official papers reveal that this discriminatory flaw has been known about for more than a year. Furthermore, law enforcement argued to overturn an initial decision that was intended to address the problem.

Police bosses were informed of the system's bias in late 2024. The government-ordered NPL review concluded the system was had a higher probability to suggest false positives for photos of females, Black people, and those aged 40 and under.

A Policy U-Turn

In reaction, the National Police Chiefs’ Council (NPCC) mandated that the confidence threshold required for possible hits be increased to a point 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 “investigative leads”. Internal records show the stricter setting reduced the number of searches resulting in potential matches from over half to a mere under 15%.

Severe Disparities

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

The ministry stated on these findings: “The testing found that in a specific scenarios the algorithm is more likely to wrongly flag some demographic groups in its search results.”

Operational Effectiveness vs. Bias

Describing the effect of the temporary raise to the system's accuracy setting, the police records note: “The change significantly reduces the impact of discrimination across protected characteristics of ethnicity, generation and gender but had a significant negative impact on operational effectiveness”. The documents further note that police units complained that “a once effective tactic now delivered outcomes of limited benefit”.

Broader Rollout Plans

Meanwhile, the government has launched a ten-week public review on its plans to widen the use of biometric scanning systems. The minister for police the relevant minister has described the technology 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: “There was very little consideration through race action plan meetings of the facial recognition rollout despite clear relevance with the plan’s concerns.

“This disclosure demonstrate once again that the pledges to combat discrimination the police has undertaken through the equality initiative are failing to be integrated into broader operations. Independent assessments have cautioned that innovative tools are being implemented in a landscape where racial disparities, inadequate oversight and faulty information gathering already persist.

“Any use of facial recognition must meet strict national standards, be independently scrutinised, and prove it reduces rather than exacerbates ethnic bias.”

Official Statement

A Home Office spokesperson said: “The Home Office takes the findings of the study seriously and we have already taken action. A updated software 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 further assessment.

“Our priority is ensuring public safety. This revolutionary tool will assist police to put criminals and rapists behind bars. There is officer review in every step of the procedure and no further action would be taken without trained officers meticulously examining the output.”