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Law enforcement agencies across the UK successfully lobbied to deploy a face scanning system acknowledged as discriminatory against females, youths, and individuals from ethnic minority groups, after complaining that a more accurate version generated a reduced number of investigative leads.

How the System Works

British police use the police national database (PND) to conduct searches using historical face recognition. This procedure entails comparing a “probe image” of a suspect against a database of more than 19 million custody photos to find possible hits.

Admitted Bias

The UK interior ministry conceded last week that the technology was flawed. This acknowledgment came after a study by the government's National Physical Laboratory found it misidentified Black and Asian people and women at much greater frequency than white men. The ministry said it “took steps on the findings”.

“It prompts the question of whether this technology only becomes effective if users accept discrimination in ethnicity and sex. Convenience is a poor argument for overriding fundamental rights.”

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 earlier ruling that was designed to mitigate the problem.

Police bosses were informed of the algorithmic discrimination in late 2024. The Home Office-commissioned laboratory study concluded the system was more likely to suggest incorrect matches for images depicting women, individuals of Black ethnicity, and those aged 40 and under.

A Reversed Decision

In response, the National Police Chiefs’ Council (NPCC) ordered that the accuracy setting required for possible hits be raised to a level where the disparity was greatly diminished.

However, this decision was overturned the next month following complaints from police that the adjusted system was generating fewer “useful lines of inquiry”. NPCC documents indicate the higher threshold reduced the proportion of searches resulting in potential matches from over half to a just 14%.

Severe Disparities

Although the authorities declined to specify what setting is currently used, the latest NPL study found the system could produce false positives for Black women almost 100 times more frequently than for Caucasian women at specific configurations.

The ministry stated on these results: “Our evaluation found that in a limited set of circumstances the algorithm is has a greater tendency to incorrectly include some population segments in its match reports.”

Balancing Utility and Fairness

Describing the effect of the brief increase to the system's accuracy setting, the police records note: “This adjustment significantly reduces the effect of bias across protected characteristics of ethnicity, age and gender but had a substantially detrimental effect on police efficiency”. The documents further note that forces argued that “a previously useful tool now delivered outcomes of limited benefit”.

Wider Implementation Proposals

Meanwhile, the government has opened a two-and-a-half-month consultation on its proposals to widen the use of facial recognition technology. Policing minister Sarah Jones has labeled the technology as the “biggest breakthrough since DNA matching”.

Expert and Oversight Concerns

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

“These revelations demonstrate yet again that the pledges to combat discrimination the police has undertaken via the equality initiative are failing to be integrated into broader operations. Independent assessments have warned that innovative tools are being rolled out in a landscape where ethnic inequalities, weak scrutiny and faulty information gathering continue to exist.

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

Official Statement

A government representative said: “We takes the conclusions of the study seriously and we have already taken action. A updated software has been externally evaluated and acquired, which has no statistically significant bias. It will be tested in the coming months and will be subject to further assessment.

“The foremost aim is ensuring public safety. This revolutionary tool will assist police to put criminals and rapists behind bars. There is human involvement in each stage of the procedure and no further action would be taken without specialist personnel carefully reviewing the results.”