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Law enforcement agencies across the United Kingdom successfully lobbied to use a face scanning system known to be biased against females, young people, and individuals from ethnic minority groups, following complaints that a more accurate version generated fewer investigative leads.

The Technology in Practice

British police utilize the national police database to carry out searches using historical face recognition. This process entails matching a reference photograph of a person of interest against a database of more than 19 million custody photos to identify possible hits.

Acknowledged Discrimination

The Home Office admitted last week that the system was biased. This acknowledgment followed a review by the National Physical Laboratory (NPL) found it incorrectly matched people of Black and Asian heritage and women at significantly higher rates than Caucasian males. The ministry said it “had acted on the findings”.

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

Long-Standing Problem

Internal documents show that this discriminatory flaw has been known about for more than a year. Furthermore, law enforcement argued to overturn an initial decision that was intended to address the problem.

Police bosses were notified of the algorithmic discrimination in late 2024. The government-ordered laboratory study found the system was had a higher probability to produce false positives for photos of females, Black people, and those aged 40 and under.

A Reversed Decision

In reaction, the National Police Chiefs’ Council (NPCC) mandated that the accuracy setting required for possible hits be increased to a point where the bias was significantly reduced.

However, this decision was reversed the following month following complaints from police that the adjusted system was producing a lower number of “useful lines of inquiry”. Internal records show the higher threshold reduced the proportion of searches resulting in potential matches from 56% to a mere under 15%.

Profound Inequalities

Although the Home Office and NPCC refused to say what setting is currently used, the latest independent review discovered the system could produce false positives for Black women almost 100 times more often than for Caucasian women at certain settings.

The Home Office commented on these results: “Our evaluation identified that in a limited set of circumstances the algorithm is more likely to incorrectly include some population segments in its search results.”

Balancing Utility and Fairness

Describing the impact of the brief increase to the system's accuracy setting, the NPCC documents note: “The change greatly lessens the impact of discrimination across protected characteristics of ethnicity, generation and gender but had a substantially detrimental effect on operational effectiveness”. The documents further note that police units argued that “a once effective tactic now delivered results of limited benefit”.

Wider Implementation Proposals

Meanwhile, the UK administration has opened a ten-week consultation on its plans to widen the use of biometric scanning systems. The minister for police the relevant minister has labeled the tool as the “biggest breakthrough since genetic fingerprinting”.

Expert and Oversight Concerns

The chair of a police oversight board, head of the independent scrutiny and oversight board for the national policing equality strategy, commented: “We observed scant discussion through race action plan meetings of the facial recognition rollout even with clear relevance with the strategy's goals.

“These revelations demonstrate yet again that the anti-racism commitments the police has undertaken via the race action plan are failing to be integrated into wider practice. Our reports have cautioned that innovative tools are being rolled out in a landscape where ethnic inequalities, weak scrutiny and poor data collection continue to exist.

“Any use of this technology must meet rigorous official guidelines, be independently scrutinised, and prove it diminishes rather than exacerbates racial disparity.”

Official Statement

A Home Office spokesperson said: “We takes the findings of the report seriously and we have implemented changes. A new algorithm has been externally evaluated and acquired, which has demonstrated no measurable discrimination. It will be tested in the coming months and will be undergo further assessment.

“Our priority is ensuring public safety. This gamechanging technology will support police to put criminals and rapists behind bars. There is officer review in each stage of the process and no arrest or charge would be pursued without trained officers carefully reviewing the output.”