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Police forces across the UK successfully lobbied to deploy a facial recognition system acknowledged as discriminatory against women, youths, and members of minority ethnic backgrounds, following complaints that a less biased version generated a reduced number of potential suspects.

How the System Works

British police utilize the national police database to conduct retrospective facial recognition searches. This process entails matching a reference photograph of a suspect against a database of more than 19 million custody photos to find potential matches.

Acknowledged Discrimination

The UK interior ministry admitted last week that the technology was flawed. This admission came after a study by the National Physical Laboratory (NPL) found it misidentified Black and Asian people and women at significantly higher rates than white men. The Home Office stated it “took steps on the findings”.

“This raises the issue of whether this technology only becomes effective if users tolerate discrimination in race and sex. Operational ease is a weak argument for disregarding basic freedoms.”

Known Issue

Official papers reveal that this discriminatory flaw has been recognized for more than a year. Furthermore, police forces lobbied to reverse an earlier ruling that was designed to mitigate the problem.

Police bosses were informed of the system's bias in late 2024. The Home Office-commissioned laboratory study concluded the system was had a higher probability to suggest incorrect matches for images depicting women, individuals of Black ethnicity, and those under 40 years old.

A Policy U-Turn

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

However, this directive was overturned the following month after forces complained that the modified technology was generating fewer “investigative leads”. NPCC documents indicate the stricter setting cut the number of queries that yielded potential matches from over half to a just under 15%.

Severe Disparities

Although the authorities refused to say what threshold is currently used, the latest NPL study discovered the system could generate incorrect matches for women of Black heritage almost 100 times more frequently than for Caucasian women at certain settings.

The Home Office stated on these findings: “Our evaluation found that in a limited set of circumstances the software is has a greater tendency to wrongly flag some population segments in its match reports.”

Operational Effectiveness vs. Bias

Outlining the effect of the brief increase to the system's confidence threshold, the NPCC documents note: “The change significantly reduces the impact of discrimination across legally safeguarded attributes of race, generation and gender but had a significant negative impact on operational effectiveness”. The documents further note that forces complained that “a previously useful tool returned outcomes of questionable value”.

Broader Rollout Plans

Meanwhile, the government has opened a ten-week consultation on its plans to widen the use of facial recognition technology. The minister for police Sarah Jones has described the technology as the “biggest breakthrough since genetic fingerprinting”.

Expert and Oversight Concerns

Abimbola Johnson, head of the independent scrutiny and oversight board for the police race action plan, commented: “There was very little discussion in 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 anti-racism commitments policing has undertaken via the race action plan are not being translated into wider practice. Our reports have cautioned that new technologies are being rolled out in a context where racial disparities, weak scrutiny and faulty information gathering already persist.

“Any use of this technology must meet strict national standards, be subject to external review, and demonstrate it diminishes rather than exacerbates ethnic bias.”

Home Office Response

A Home Office spokesperson said: “The Home Office takes the findings of the report seriously and we have already taken action. A updated software has been independently tested and acquired, which has demonstrated no measurable discrimination. It will be trialled early next year and will be subject to evaluation.

“Our priority is protecting the public. This gamechanging technology will support police to apprehend and prosecute offenders. There is human involvement in every step of the process and no further action would be pursued without trained officers carefully reviewing the output.”