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Law enforcement agencies across the UK successfully lobbied to use a facial recognition system known to be discriminatory against females, youths, and members of minority ethnic backgrounds, following complaints that a more accurate version generated fewer investigative leads.

The Technology in Practice

UK forces utilize the national police database to conduct retrospective facial recognition searches. This process involves matching a “probe image” of a suspect against a repository of more than 19 million mugshots to find possible hits.

Acknowledged Discrimination

The Home Office conceded last week that the technology was biased. This acknowledgment followed a review by the government's National Physical Laboratory found it misidentified people of Black and Asian heritage and women at significantly higher rates than Caucasian males. The ministry stated it “had acted on the findings”.

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

Known Issue

Official papers show that this bias has been recognized for over twelve months. Furthermore, police forces argued to overturn an initial decision that was intended to address the problem.

Police bosses were informed of the algorithmic discrimination in September 2024. The Home Office-commissioned laboratory study concluded the system was more likely to produce false positives for images depicting women, individuals of Black ethnicity, and those under 40 years old.

A Reversed Decision

In reaction, the national police leadership body ordered that the accuracy setting required for potential matches be increased to a level where the bias was greatly diminished.

However, this directive was overturned the following month following complaints from police that the modified technology was generating a lower number of “useful lines of inquiry”. NPCC documents show the higher threshold reduced the proportion of queries resulting in possible identifications from over half to a mere under 15%.

Severe Disparities

Although the Home Office and NPCC refused to say what setting is now in operation, the recent NPL study discovered the system could generate incorrect matches for women of Black heritage nearly a hundred times more frequently than for Caucasian women at specific configurations.

The ministry stated on these findings: “The testing 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

Outlining the effect of the brief increase to the system's accuracy setting, the NPCC documents state: “This adjustment significantly reduces the impact of bias across protected characteristics of race, generation and gender but had a substantially detrimental effect on operational effectiveness”. The documents further note that forces complained that “a previously useful tool now delivered results of questionable value”.

Broader Rollout Plans

Meanwhile, the government has launched a ten-week 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”.

Expert and Oversight Concerns

Abimbola Johnson, chair of the advisory panel for the police race action plan, commented: “We observed scant discussion in race action plan meetings of the technology deployment despite clear relevance with the strategy's goals.

“These revelations show once again that the pledges to combat discrimination policing has made via the race action plan are not being translated into broader operations. Independent assessments have warned that new technologies are being rolled out in a context where ethnic inequalities, inadequate oversight and poor data collection already persist.

“All deployment of this technology must adhere to rigorous official guidelines, be subject to external review, and prove it reduces rather than compounds ethnic bias.”

Official Statement

A Home Office spokesperson stated: “The Home Office treat the findings of the study seriously and we have implemented changes. A updated software has been independently tested and acquired, which has demonstrated no measurable discrimination. It will be trialled early next year and will be subject to further assessment.

“Our priority is ensuring public safety. This revolutionary tool will support police to apprehend and prosecute offenders. There is human involvement in every step of the procedure and no further action would be pursued without trained officers meticulously examining the results.”