British Police Forces Lobbied to Employ Discriminatory Face Scanning Technology

Law enforcement agencies across the UK successfully lobbied to use a face scanning system known to be biased against females, young people, and individuals from minority ethnic backgrounds, following complaints that a less biased version produced a reduced number of potential suspects.

How the System Works

British police use the national police database to conduct searches using historical face recognition. This procedure entails matching a “probe image” of a person of interest against a database of over 19 million custody photos to find potential matches.

Acknowledged Discrimination

The Home Office admitted last week that the technology was flawed. This admission followed a study by the National Physical Laboratory (NPL) determined it incorrectly matched people of Black and Asian heritage and women at much greater frequency than Caucasian males. The Home Office said it “took steps on the findings”.

“It prompts the issue of whether this technology only becomes useful if users tolerate biases in race and gender. Convenience is a poor argument for overriding fundamental rights.”

Long-Standing Problem

Official papers reveal that this discriminatory flaw has been recognized for over twelve months. Furthermore, law enforcement lobbied to reverse an initial decision that was intended to address the problem.

Senior officers were informed of the system's bias in September 2024. The Home Office-commissioned NPL review found the system was more likely to suggest incorrect matches for photos of women, Black people, and those under 40 years old.

A Reversed Decision

In response, the National Police Chiefs’ Council (NPCC) mandated 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 next month after forces complained that the adjusted system was producing fewer “useful lines of inquiry”. Internal records indicate the higher threshold cut the proportion of searches that yielded possible identifications from 56% to a just under 15%.

Severe Disparities

Although the Home Office and NPCC declined to specify what setting is now in operation, the recent NPL study found the system could generate incorrect matches for women of Black heritage almost 100 times more often than for Caucasian women at specific configurations.

The ministry commented on these results: “The testing identified 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 police records state: “This adjustment significantly reduces the impact of discrimination across protected characteristics of ethnicity, age and sex but had a significant negative impact on police efficiency”. The papers add that forces argued that “a previously useful tool now delivered outcomes of limited benefit”.

Wider Implementation Proposals

Meanwhile, the government has launched a two-and-a-half-month consultation on its plans 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”.

Criticism from Advisors and Monitors

Abimbola Johnson, head of the advisory panel for the national policing equality strategy, commented: “We observed very little consideration in race action plan meetings of the facial recognition rollout despite clear relevance with the strategy's goals.

“This disclosure demonstrate yet again that the anti-racism commitments the police has made via the equality initiative are failing to be integrated into wider practice. Our reports have cautioned that new technologies are being implemented in a landscape where racial disparities, weak scrutiny and poor data collection continue to exist.

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

Official Statement

A Home Office spokesperson said: “We treat the findings 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 trialled in the coming months and will be undergo evaluation.

“The foremost aim is ensuring public safety. This gamechanging technology will support officers to apprehend and prosecute offenders. There is human involvement in each stage of the procedure and no arrest or charge would be taken without specialist personnel carefully reviewing the results.”