UK Police Forces Campaign to Employ Discriminatory Face Scanning Systems

Law enforcement agencies across the United Kingdom effectively campaigned to deploy a facial recognition system acknowledged as discriminatory against women, young people, and members of minority ethnic backgrounds, after complaining that a more accurate version generated fewer potential suspects.

How the System Works

UK forces utilize the police national database (PND) to conduct searches using historical face recognition. This process entails comparing a reference photograph of a person of interest against a repository of over 19 million custody photos to identify potential matches.

Acknowledged Discrimination

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

“This raises the issue of whether this technology only becomes useful if users tolerate discrimination in race and sex. Operational ease is a poor argument for disregarding fundamental rights.”

Known Issue

Internal documents show that this bias has been known about for more than a year. Furthermore, law enforcement argued to overturn an initial decision that was intended to address the problem.

Senior officers were informed 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 photos of women, individuals of Black ethnicity, and those under 40 years old.

A Policy U-Turn

In reaction, the national police leadership body ordered that the accuracy setting required for possible hits be increased to a level where the bias was significantly reduced.

However, this decision was overturned the following month following complaints from police that the modified technology was producing a lower number of “useful lines of inquiry”. Internal records show the stricter setting reduced the number of queries that yielded possible identifications from 56% to a mere 14%.

Severe Disparities

Although the authorities refused to say what setting is now in operation, the recent NPL study found the system could generate false positives for women of Black heritage almost 100 times more frequently than for Caucasian women at specific configurations.

The Home Office commented on these findings: “Our evaluation found that in a limited set of circumstances the algorithm is more likely to incorrectly include some population segments in its match reports.”

Balancing Utility and Fairness

Describing the effect of the brief increase to the system's accuracy setting, the police records note: “The change significantly reduces the impact of discrimination across legally safeguarded attributes of ethnicity, age and sex but had a substantially detrimental effect on operational effectiveness”. The documents further note that police units complained that “a previously useful tool now delivered results of limited benefit”.

Wider Implementation Proposals

Meanwhile, the government has launched a ten-week consultation on its proposals to expand the use of facial recognition technology. The minister for police Sarah Jones has labeled the tool as the “most significant advance since genetic fingerprinting”.

Expert and Oversight Concerns

The chair of a police oversight board, chair of the advisory panel for the police race action plan, commented: “There was very little consideration in race action plan meetings of the technology deployment despite obvious cross-over with the plan’s concerns.

“These revelations demonstrate once again that the anti-racism commitments the police has made through the equality initiative are failing to be integrated into wider practice. Independent assessments have warned that innovative tools are being implemented in a context where ethnic inequalities, weak scrutiny and poor data collection already persist.

“All deployment of this technology must meet rigorous official guidelines, be independently scrutinised, and prove it reduces rather than exacerbates ethnic bias.”

Home Office Response

A government representative said: “The Home Office takes the findings of the study with utmost gravity and we have already taken action. A new algorithm 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.

“The foremost aim is ensuring public safety. This gamechanging technology will assist police to apprehend and prosecute offenders. There is human involvement in each stage of the process and no arrest or charge would be pursued without trained officers carefully reviewing the results.”