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Law enforcement agencies across the UK successfully lobbied to deploy a facial recognition system known to be biased against females, youths, and individuals from ethnic minority groups, after complaining that a less biased version generated a reduced number of potential suspects.

How the System Works

UK forces use the police national database (PND) to carry out retrospective facial recognition searches. This procedure entails comparing a reference photograph of a person of interest against a database of over 19 million custody photos to find possible hits.

Acknowledged Discrimination

The UK interior ministry admitted last week that the system was flawed. This admission came after a study by the government's National Physical Laboratory found it incorrectly matched Black and Asian people and females at significantly higher rates than white men. The ministry stated it “had acted on the findings”.

“This raises the question of whether this technology only becomes effective if users accept biases in race and gender. Operational ease is a poor argument for overriding basic freedoms.”

Long-Standing Problem

Internal documents show that this bias has been known about for more than a year. 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 government-ordered NPL review found the system was more likely 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 raised to a level where the bias was greatly diminished.

However, this decision was overturned the following month after forces complained that the adjusted system was generating a lower number of “investigative leads”. NPCC documents show the higher threshold cut the number of searches resulting in possible identifications from over half to a just under 15%.

Severe Disparities

Although the authorities declined to specify what setting is now in operation, the latest NPL study discovered the system could produce false positives for Black women nearly a hundred 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 algorithm is more likely to incorrectly include some demographic groups in its search results.”

Operational Effectiveness vs. Bias

Outlining the effect of the temporary raise to the system's accuracy setting, the police records note: “The change greatly lessens the effect of bias across protected characteristics of race, generation and sex but had a substantially detrimental effect on police efficiency”. The documents further note that forces complained that “a once effective tactic now delivered outcomes of questionable value”.

Wider Implementation Proposals

Meanwhile, the government has launched a two-and-a-half-month consultation on its plans to expand the use of facial recognition technology. The minister for police Sarah Jones has labeled the tool 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 through race action plan meetings of the technology deployment despite obvious cross-over with the strategy's goals.

“These revelations demonstrate yet again that the anti-racism commitments policing has made through the race action plan are not being translated into wider practice. Our reports have warned that new technologies are being implemented in a context where ethnic inequalities, inadequate oversight and faulty information gathering already persist.

“All deployment of facial recognition must adhere to strict national standards, be subject to external review, and prove it diminishes rather than compounds ethnic bias.”

Official Statement

A government representative stated: “We treat the findings of the report seriously and we have implemented changes. A updated software has been externally evaluated and acquired, which has no statistically significant bias. It will be trialled early next year and will be subject to evaluation.

“Our priority is protecting the public. This revolutionary tool will support police to put criminals and rapists behind bars. There is human involvement in each stage of the process and no arrest or charge would be pursued without specialist personnel meticulously examining the output.”