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Law enforcement agencies across the UK successfully lobbied to use a face scanning system known to be biased against females, youths, and members of minority ethnic backgrounds, following complaints that a more accurate version generated a reduced number of potential suspects.

The Technology in Practice

UK forces utilize the police national database (PND) to conduct searches using historical face recognition. This procedure involves matching a reference photograph of a suspect against a repository of over 19 million mugshots to identify possible hits.

Admitted Bias

The Home Office admitted last week that the technology was biased. 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 ministry 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. Convenience is a poor argument for disregarding fundamental rights.”

Long-Standing Problem

Internal documents show that this discriminatory flaw has been recognized for more than a year. Furthermore, law enforcement argued to overturn an earlier ruling that was designed to address the problem.

Police bosses were notified of the system's bias in late 2024. The Home Office-commissioned laboratory study concluded the system was more likely to produce false positives for photos of women, individuals of Black ethnicity, and those under 40 years old.

A Reversed Decision

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

However, this decision was overturned the following month following complaints from police that the modified technology was producing a lower number of “investigative leads”. NPCC documents indicate the higher threshold reduced the proportion of searches that yielded possible identifications from over half to a just 14%.

Profound Inequalities

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

The ministry commented on these results: “The testing found that in a specific scenarios the software is more likely to incorrectly include some population segments in its search results.”

Operational Effectiveness vs. Bias

Outlining the impact of the brief increase to the system's confidence threshold, the police records state: “The change significantly reduces the effect of bias across legally safeguarded attributes of race, generation and gender but had a substantially detrimental effect on operational effectiveness”. The documents further note that police units complained that “a once effective tactic returned results of limited benefit”.

Wider Implementation Proposals

Meanwhile, the UK administration has launched a two-and-a-half-month consultation on its proposals to widen the use of biometric scanning systems. The minister for police Sarah Jones has described the tool as the “most significant advance since DNA matching”.

Expert and Oversight Concerns

Abimbola Johnson, chair of the independent scrutiny and oversight board for the national policing equality strategy, commented: “We observed very little discussion through race action plan meetings of the facial recognition rollout even with obvious cross-over with the strategy's goals.

“These revelations demonstrate yet again that the pledges to combat discrimination policing has undertaken through the race action plan are not being translated into broader operations. Our reports have warned that new technologies are being rolled out in a landscape where ethnic inequalities, inadequate oversight and faulty information gathering continue to exist.

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

Official Statement

A Home Office spokesperson stated: “We treat the conclusions of the report 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 in the coming months and will be subject to evaluation.

“The foremost aim is ensuring public safety. This revolutionary tool will support officers to apprehend and prosecute offenders. There is officer review in every step of the procedure and no further action would be taken without trained officers meticulously examining the output.”