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Law enforcement agencies across the United Kingdom successfully lobbied to deploy a facial recognition system acknowledged as discriminatory against women, young people, and individuals from ethnic minority groups, following complaints that a more accurate version produced a reduced number of investigative leads.

How the System Works

UK forces utilize the national police database to carry out searches using historical face recognition. This procedure involves matching a reference photograph of a suspect against a database of more than 19 million custody photos to find potential matches.

Acknowledged Discrimination

The Home Office admitted last week that the technology was biased. This admission followed a review by the National Physical Laboratory (NPL) found it incorrectly matched Black and Asian people and women at significantly higher rates than white men. The Home Office said it “took steps on the findings”.

“It prompts the issue of whether this technology only becomes effective if users accept biases in ethnicity and sex. Operational ease is a poor argument for disregarding fundamental rights.”

Known Issue

Internal documents reveal that this discriminatory flaw has been known about for more than a year. Furthermore, law enforcement lobbied to reverse an initial decision that was designed to mitigate the problem.

Police bosses were informed of the system's bias in late 2024. The Home Office-commissioned NPL review concluded the system was had a higher probability to produce 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 confidence threshold required for possible hits be raised to a level where the disparity was significantly reduced.

However, this directive was overturned the following month after forces complained that the adjusted system was producing a lower number of “useful lines of inquiry”. NPCC documents indicate the higher threshold cut the number of queries that yielded potential matches from 56% to a just under 15%.

Profound Inequalities

Although the Home Office and NPCC declined to specify what setting is currently used, the latest NPL study discovered the system could generate false positives for women of Black heritage nearly a hundred times more frequently than for Caucasian women at certain settings.

The ministry stated on these findings: “Our evaluation found that in a limited set of circumstances the software is has a greater tendency to incorrectly include some demographic groups in its match reports.”

Operational Effectiveness vs. Bias

Describing the impact of the brief increase to the system's accuracy setting, the police records state: “The change significantly reduces the impact of discrimination across protected characteristics of ethnicity, age and sex but had a significant negative impact on police efficiency”. The documents add that forces argued that “a previously useful tool now delivered outcomes of limited benefit”.

Broader Rollout Plans

Meanwhile, the UK administration has launched a ten-week consultation on its plans to expand the use of biometric scanning systems. The minister for police the relevant minister has described the technology as the “biggest breakthrough since DNA matching”.

Criticism from Advisors and Monitors

Abimbola Johnson, chair of the advisory panel for the police race action plan, commented: “We observed scant discussion in race action plan meetings of the technology deployment even with obvious cross-over with the plan’s concerns.

“This disclosure demonstrate once again that the anti-racism commitments policing has undertaken via the race action plan are failing to be integrated into broader operations. Our reports have warned that innovative tools are being rolled out in a landscape where ethnic inequalities, weak scrutiny and faulty information gathering already persist.

“All deployment of this technology must adhere to strict national standards, be independently scrutinised, and demonstrate it diminishes rather than compounds racial disparity.”

Home Office Response

A government representative stated: “The Home Office takes the findings of the report 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 evaluation.

“The foremost aim is protecting the public. 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 arrest or charge would be taken without specialist personnel carefully reviewing the output.”