UK Police Forces Campaign to Employ Biased Facial Recognition Systems

Police forces across the UK effectively campaigned to deploy a facial recognition system known to be biased against women, young people, and individuals from ethnic minority groups, after complaining that a more accurate version generated fewer investigative leads.

The Technology in Practice

UK forces use the national police database to conduct retrospective facial recognition searches. This process entails comparing a reference photograph of a suspect against a database of over 19 million custody photos to find potential matches.

Admitted Bias

The UK interior ministry conceded last week that the technology was flawed. This acknowledgment followed a review by the government's National Physical Laboratory determined it incorrectly matched people of Black and Asian heritage and females 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 tolerate discrimination in race and gender. Operational ease is a weak argument for disregarding fundamental rights.”

Long-Standing Problem

Internal documents reveal that this discriminatory flaw has been recognized for more than a year. Furthermore, law enforcement argued to overturn an initial decision that was intended to mitigate the problem.

Senior officers were notified of the system's bias in September 2024. The government-ordered NPL review concluded the system was had a higher probability to produce false positives for images depicting females, Black people, and those under 40 years old.

A Policy U-Turn

In response, the national police leadership body ordered that the accuracy setting required for possible hits be increased to a point where the disparity was greatly diminished.

However, this directive was overturned the following month following complaints from police that the modified technology was producing a lower number of “useful lines of inquiry”. Internal records indicate the stricter setting reduced the proportion of searches that yielded possible identifications from 56% to a mere 14%.

Severe Disparities

Although the authorities declined to specify what setting is currently used, the latest independent review discovered the system could generate false positives for women of Black heritage nearly a hundred times more frequently than for white women at specific configurations.

The ministry commented on these results: “Our evaluation found that in a limited set of circumstances the software is more likely to wrongly flag some population segments in its search results.”

Operational Effectiveness vs. Bias

Describing the effect of the temporary raise to the system's confidence threshold, the NPCC documents state: “The change greatly lessens the effect of bias across protected characteristics of ethnicity, generation and sex but had a significant negative impact on police efficiency”. The papers add that police units argued that “a once effective tactic now delivered results of limited benefit”.

Broader Rollout Plans

Meanwhile, the government has opened a two-and-a-half-month public review on its plans to expand the use of biometric scanning systems. The minister for police the relevant minister 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 independent scrutiny and oversight board for the police race action plan, said: “We observed scant consideration through race action plan meetings of the facial recognition rollout even with clear relevance with the strategy's goals.

“This disclosure demonstrate yet again that the anti-racism commitments the police has undertaken via the equality initiative are failing to be integrated into broader operations. Our reports have warned that innovative tools are being rolled out in a context where ethnic inequalities, inadequate oversight and poor data collection already persist.

“Any use of facial recognition must adhere to rigorous official guidelines, be independently scrutinised, and demonstrate it reduces rather than compounds racial disparity.”

Home Office Response

A government representative said: “The Home Office treat the conclusions of the report seriously and we have already taken action. A new algorithm has been externally evaluated and acquired, which has demonstrated no measurable discrimination. It will be tested early next year and will be undergo evaluation.

“Our priority is protecting the public. This gamechanging technology will support police to apprehend and prosecute offenders. There is human involvement in every step of the process and no further action would be taken without specialist personnel meticulously examining the results.”