UK Law Enforcement Agencies Lobbied to Employ Discriminatory Facial Recognition Technology

Law enforcement agencies across the UK successfully lobbied to use a face scanning system acknowledged as biased against women, youths, and members of ethnic minority groups, after complaining that a more accurate version generated a reduced number of potential suspects.

How the System Works

UK forces utilize the national police database to conduct searches using historical face recognition. This procedure entails matching a “probe image” of a suspect against a repository of more than 19 million custody photos to find possible hits.

Admitted Bias

The UK interior ministry admitted last week that the technology was flawed. This admission followed a review by the National Physical Laboratory (NPL) determined it incorrectly matched Black and Asian people and women at significantly higher rates than Caucasian males. The ministry said it “had acted on the findings”.

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

Long-Standing Problem

Internal documents show that this bias 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 notified of the system's bias in September 2024. The Home Office-commissioned laboratory study found the system was had a higher probability to produce false positives for photos of women, Black people, and those under 40 years old.

A Policy U-Turn

In response, the national police leadership body ordered that the confidence threshold required for potential matches be raised to a level where the bias was significantly reduced.

However, this directive was reversed the next month after forces complained that the modified technology was generating fewer “investigative leads”. NPCC documents show the stricter setting cut the proportion of queries that yielded possible identifications from 56% to a mere under 15%.

Profound Inequalities

Although the authorities refused to say what threshold is now in operation, the recent independent review discovered the system could generate incorrect matches for Black women almost 100 times more frequently than for white women at certain settings.

The ministry stated on these findings: “The testing found that in a limited set of circumstances the algorithm is has a greater tendency to wrongly flag some population segments in its search results.”

Balancing Utility and Fairness

Describing the effect of the brief increase to the system's confidence threshold, the police records state: “The change significantly reduces the effect of discrimination across protected characteristics of race, age and gender but had a significant negative impact on police efficiency”. The documents further note that police units complained that “a once effective tactic now delivered outcomes of limited benefit”.

Broader Rollout Plans

Meanwhile, the UK administration has launched a ten-week consultation on its plans to widen the use of facial recognition technology. The minister for police Sarah Jones has described the technology as the “biggest breakthrough since DNA matching”.

Expert and Oversight Concerns

The chair of a police oversight board, chair of the independent scrutiny and oversight board for the national policing equality strategy, commented: “We observed scant consideration in equality strategy sessions of the technology deployment even with clear relevance with the strategy's goals.

“These revelations show yet again that the anti-racism commitments policing has undertaken via the equality initiative are not being translated into broader operations. Our reports have warned that innovative tools are being rolled out in a landscape where ethnic inequalities, weak scrutiny 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 reduces rather than compounds ethnic bias.”

Home Office Response

A Home Office spokesperson said: “The Home Office takes the findings of the study with utmost gravity and we have implemented changes. A new algorithm has been independently tested and acquired, which has demonstrated no measurable discrimination. It will be tested early next year and will be subject to evaluation.

“The foremost aim is ensuring public safety. This gamechanging technology will assist officers to apprehend and prosecute offenders. There is human involvement in every step of the procedure and no further action would be pursued without specialist personnel carefully reviewing the output.”