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Police forces across the United Kingdom successfully lobbied to deploy a face scanning system known to be discriminatory against women, youths, and individuals from minority ethnic backgrounds, after complaining that a less biased version generated a reduced number of investigative leads.

The Technology in Practice

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

Acknowledged Discrimination

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 determined it misidentified Black and Asian people and females at significantly higher rates than Caucasian males. The Home Office said it “had acted on the findings”.

“This raises the issue of whether facial recognition only becomes effective if users accept biases in ethnicity and gender. Operational ease is a weak argument for overriding fundamental rights.”

Long-Standing Problem

Internal documents reveal that this discriminatory flaw has been recognized for over twelve months. Furthermore, police forces lobbied to reverse an initial decision that was intended to address the problem.

Senior officers were notified of the algorithmic discrimination in late 2024. The government-ordered NPL review found the system was had a higher probability to suggest incorrect matches for images depicting females, Black people, and those under 40 years old.

A Policy U-Turn

In reaction, the national police leadership body ordered that the accuracy setting required for potential matches be increased to a level where the disparity was greatly diminished.

However, this decision was overturned the next month after forces complained that the adjusted system was generating a lower number of “investigative leads”. NPCC documents show the stricter setting reduced the number of searches resulting in possible identifications from over half to a mere 14%.

Severe Disparities

Although the authorities refused to say what setting is now in operation, the latest independent review found the system could produce incorrect matches for Black women almost 100 times more often than for white women at certain settings.

The ministry commented on these findings: “Our evaluation identified 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 confidence threshold, the NPCC documents note: “This adjustment greatly lessens the effect of discrimination across protected characteristics of ethnicity, age and gender but had a substantially detrimental effect on operational effectiveness”. The documents further note that forces argued that “a previously useful tool now delivered results of limited benefit”.

Wider Implementation Proposals

Meanwhile, the government has opened a two-and-a-half-month public review on its plans to expand the use of facial recognition technology. The minister for police Sarah Jones has described the tool as the “most significant advance since DNA matching”.

Criticism from Advisors and Monitors

Abimbola Johnson, head of the independent scrutiny and oversight board for the national policing equality strategy, said: “There was very little consideration through equality strategy sessions of the facial recognition rollout even with clear relevance with the plan’s concerns.

“This disclosure demonstrate once again that the anti-racism commitments the police has made through the equality initiative are failing to be integrated into wider practice. Our reports have warned that innovative tools are being implemented in a context where racial disparities, inadequate oversight and faulty information gathering continue to exist.

“Any use of facial recognition must meet strict national standards, be subject to external review, and prove it reduces rather than exacerbates ethnic bias.”

Home Office Response

A government representative stated: “The Home Office treat the findings of the report seriously and we have implemented changes. A updated software has been externally evaluated and procured, which has demonstrated no measurable discrimination. It will be tested in the coming months and will be subject to further assessment.

“The foremost aim is ensuring public safety. This gamechanging technology will support officers to apprehend and prosecute offenders. There is officer review in every step of the process and no further action would be pursued without specialist personnel meticulously examining the results.”