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Police forces across the United Kingdom effectively campaigned to deploy a face scanning system acknowledged as biased against women, youths, and individuals from minority ethnic backgrounds, after complaining that a more accurate version produced a reduced number of investigative leads.

The Technology in Practice

British police utilize the police national database (PND) to carry out searches using historical face recognition. This process involves matching a “probe image” of a suspect against a database of more than 19 million mugshots to find potential matches.

Acknowledged Discrimination

The UK interior ministry conceded last week that the system was biased. This admission followed a review by the National Physical Laboratory (NPL) found it misidentified people of Black and Asian heritage and women at significantly higher rates than Caucasian males. The Home Office stated it “took steps on the findings”.

“It prompts the question of whether this technology only becomes effective if users accept discrimination in ethnicity and gender. Operational ease is a poor argument for overriding basic freedoms.”

Known Issue

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

Senior officers were informed of the algorithmic discrimination in September 2024. The government-ordered laboratory study concluded the system was had a higher probability to produce incorrect matches for photos of women, Black people, and those under 40 years old.

A Reversed Decision

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

However, this decision was overturned the next month after forces complained that the modified technology was generating a lower number of “investigative leads”. Internal records indicate the stricter setting reduced the proportion of searches resulting in possible identifications from 56% to a just 14%.

Severe Disparities

Although the Home Office and NPCC declined to specify what threshold is now in operation, the recent independent review found the system could generate incorrect matches for women of Black heritage nearly a hundred times more frequently than for white women at specific configurations.

The ministry stated on these findings: “Our evaluation identified that in a specific scenarios the algorithm is has a greater tendency to wrongly flag some demographic groups in its match reports.”

Balancing Utility and Fairness

Describing the impact of the brief increase to the system's confidence threshold, the police records state: “The change significantly reduces the effect of bias across protected characteristics of ethnicity, generation and gender but had a significant negative impact on police efficiency”. The papers add that forces argued that “a once effective tactic now delivered outcomes of questionable value”.

Wider Implementation Proposals

Meanwhile, the UK administration has opened a two-and-a-half-month consultation on its proposals to widen the use of biometric scanning systems. Policing minister the relevant minister has described the technology as the “biggest breakthrough since genetic fingerprinting”.

Expert and Oversight Concerns

Abimbola Johnson, head of the advisory panel for the police race action plan, said: “There was scant discussion through race action plan meetings of the facial recognition rollout even with obvious cross-over with the plan’s concerns.

“These revelations show once again that the pledges to combat discrimination policing has made via the race action plan are failing to be integrated into wider practice. Independent assessments have warned that new technologies are being implemented in a landscape where racial disparities, weak scrutiny and poor data collection already persist.

“Any use of facial recognition must adhere to strict national standards, be independently scrutinised, and prove it reduces rather than exacerbates ethnic bias.”

Official Statement

A government representative said: “We takes the conclusions of the report seriously and we have implemented changes. 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 undergo evaluation.

“The foremost aim is protecting the public. This gamechanging technology will support police to apprehend and prosecute offenders. There is human involvement in each stage of the process and no arrest or charge would be taken without trained officers meticulously examining the output.”