🔗 Share this article

Law enforcement agencies across the United Kingdom successfully lobbied to deploy a face scanning system known to be biased against females, youths, and members of minority ethnic backgrounds, following complaints that a less biased version produced fewer potential suspects.

How the System Works

British police utilize the national police database to carry out retrospective facial recognition searches. This procedure involves comparing a “probe image” of a person of interest against a repository of over 19 million custody photos to identify possible hits.

Admitted Bias

The UK interior ministry conceded last week that the technology was biased. This admission followed a review by the National Physical Laboratory (NPL) determined it misidentified Black and Asian people and females at much greater frequency than Caucasian males. The ministry stated it “had acted on the findings”.

“This raises the issue of whether facial recognition only becomes useful if users tolerate discrimination in ethnicity and gender. Operational ease is a poor argument for disregarding basic freedoms.”

Long-Standing Problem

Internal documents show that this bias has been known about for more than a year. Furthermore, police forces lobbied to reverse an initial decision that was intended to address the problem.

Senior officers were informed of the system's bias in late 2024. The government-ordered laboratory study concluded the system was more likely to suggest incorrect matches for images depicting females, individuals of Black ethnicity, and those under 40 years old.

A Policy U-Turn

In reaction, the National Police Chiefs’ Council (NPCC) mandated that the accuracy setting required for potential matches be raised to a point where the bias was greatly diminished.

However, this directive was reversed the next month after forces complained 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 56% to a just 14%.

Severe Disparities

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

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

Balancing Utility and Fairness

Describing the effect of the brief increase to the system's confidence threshold, the NPCC documents note: “This adjustment greatly lessens the effect of discrimination across legally safeguarded attributes of ethnicity, generation and gender but had a substantially detrimental effect on operational effectiveness”. The documents further note that forces argued that “a once effective tactic returned outcomes of questionable value”.

Broader Rollout Plans

Meanwhile, the UK administration has launched a two-and-a-half-month public review on its proposals to expand the use of facial recognition technology. Policing minister Sarah Jones has described the tool as the “most significant advance since DNA matching”.

Criticism from Advisors and Monitors

Abimbola Johnson, chair of the independent scrutiny and oversight board for the police race action plan, said: “We observed scant discussion through equality strategy sessions of the facial recognition rollout even with obvious cross-over with the plan’s concerns.

“These revelations demonstrate once again that the pledges to combat discrimination the police has undertaken via the equality initiative are failing to be integrated into wider practice. Independent assessments have warned that new technologies are being rolled out in a context where ethnic inequalities, inadequate oversight and faulty information gathering continue to exist.

“All deployment of facial recognition must adhere to rigorous official guidelines, be independently scrutinised, and demonstrate it diminishes rather than compounds ethnic bias.”

Official Statement

A government representative said: “We takes the findings of the report with utmost gravity and we have implemented changes. A updated software has been independently tested and procured, which has demonstrated no measurable discrimination. It will be trialled in the coming months and will be undergo evaluation.

“The foremost aim is ensuring public safety. This revolutionary tool will assist officers to put criminals and rapists behind bars. There is human involvement in every step of the procedure and no further action would be taken without trained officers meticulously examining the results.”