UK Police Forces Lobbied to Use Discriminatory Face Scanning Systems

Police forces across the United Kingdom successfully lobbied to deploy a face scanning system acknowledged as discriminatory against women, young people, and individuals from ethnic minority groups, after complaining that a less biased version produced a reduced number of potential suspects.

How the System Works

UK forces utilize the police national database (PND) to conduct searches using historical face recognition. This procedure involves matching a “probe image” of a suspect against a database of more than 19 million mugshots to identify potential matches.

Admitted Bias

The UK interior ministry admitted last week that the system was flawed. This acknowledgment followed a study by the National Physical Laboratory (NPL) found it incorrectly matched Black and Asian people and women at significantly higher rates than white men. The ministry said it “had acted on the findings”.

“It prompts the issue of whether this technology only becomes effective if users accept biases in race and gender. Convenience is a weak argument for overriding basic freedoms.”

Known Issue

Official papers show that this discriminatory flaw has been known about for more than a year. Furthermore, law enforcement argued to overturn an earlier ruling that was designed to mitigate the problem.

Senior officers were informed of the system's bias in late 2024. The government-ordered NPL review found the system was had a higher probability to produce false positives for images depicting women, individuals of Black ethnicity, and those aged 40 and under.

A Reversed Decision

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

However, this directive was overturned the next month following complaints from police that the modified technology was generating fewer “investigative leads”. Internal records show the stricter setting cut the proportion of queries that yielded potential matches from 56% to a just 14%.

Severe Disparities

Although the Home Office and NPCC refused to say what setting is now in operation, the recent independent review found the system could produce incorrect matches for women of Black heritage nearly a hundred times more often than for white women at certain settings.

The ministry commented on these findings: “The testing found that in a limited set of circumstances the software is more likely to wrongly flag some population segments in its match reports.”

Operational Effectiveness vs. Bias

Describing the impact of the brief increase to the system's accuracy setting, the NPCC documents state: “The change greatly lessens the impact of bias across protected characteristics of ethnicity, age and gender but had a substantially detrimental effect on police efficiency”. The documents add that forces argued that “a once effective tactic now delivered outcomes of questionable value”.

Wider Implementation Proposals

Meanwhile, the government has launched a ten-week consultation on its plans to widen the use of biometric scanning systems. Policing minister Sarah Jones has described the tool as the “most significant advance 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: “There was very little discussion through equality strategy sessions of the facial recognition rollout despite clear relevance with the plan’s concerns.

“This disclosure show yet again that the pledges to combat discrimination policing has undertaken through the race action plan are failing to be integrated into broader operations. Our reports have cautioned that new technologies are being implemented in a landscape where ethnic inequalities, inadequate oversight and faulty information gathering continue to exist.

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

Home Office Response

A government representative stated: “The Home Office takes the conclusions of the study with utmost gravity and we have already taken action. A updated software has been independently tested and acquired, which has no statistically significant bias. It will be tested in the coming months and will be undergo further assessment.

“The foremost aim is ensuring public safety. This gamechanging technology will support officers to put criminals and rapists behind bars. There is human involvement in each stage of the process and no further action would be pursued without specialist personnel meticulously examining the results.”