British Law Enforcement Agencies Lobbied to Employ Discriminatory Facial Recognition Systems

Law enforcement agencies across the United Kingdom effectively campaigned to deploy a face scanning system acknowledged as discriminatory against women, youths, and individuals from minority ethnic backgrounds, after complaining that a more accurate version produced fewer potential suspects.

How the System Works

UK forces utilize the national police database to conduct searches using historical face recognition. This process involves matching a “probe image” of a suspect against a repository of more than 19 million mugshots to identify possible hits.

Admitted Bias

The Home Office admitted last week that the technology was flawed. This admission followed a review by the National Physical Laboratory (NPL) determined it incorrectly matched people of Black and Asian heritage and females at significantly higher rates than white men. The ministry stated it “took steps on the findings”.

“This raises the question of whether this technology only becomes effective if users accept biases in race and gender. Convenience is a weak argument for disregarding basic freedoms.”

Known Issue

Internal documents show that this discriminatory flaw has been known about for over twelve months. Furthermore, law enforcement argued to overturn an earlier ruling that was designed to address the problem.

Senior officers were informed of the algorithmic discrimination in September 2024. The Home Office-commissioned NPL review found the system was had a higher probability to produce incorrect matches for images depicting females, individuals of Black ethnicity, and those aged 40 and under.

A Reversed Decision

In response, the national police leadership body mandated that the accuracy setting required for potential matches be raised to a level where the bias was greatly diminished.

However, this decision was reversed the following month following complaints from police that the adjusted system was generating fewer “investigative leads”. NPCC documents indicate the higher threshold reduced the proportion of queries resulting in possible identifications from 56% to a mere under 15%.

Severe Disparities

Although the Home Office and NPCC refused to say what threshold is currently used, the recent NPL study discovered the system could produce false positives for Black women almost 100 times more often than for Caucasian women at specific configurations.

The Home Office stated on these findings: “The testing found that in a specific scenarios the algorithm is more likely to wrongly flag some population segments in its match reports.”

Operational Effectiveness vs. Bias

Describing the impact of the temporary raise to the system's confidence threshold, the police records state: “The change greatly lessens the effect of discrimination across legally safeguarded attributes of ethnicity, generation and sex but had a substantially detrimental effect on operational effectiveness”. The papers add that forces argued that “a once effective tactic returned results of limited benefit”.

Broader Rollout Plans

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

Criticism from Advisors and Monitors

Abimbola Johnson, chair of the advisory panel for the police race action plan, said: “There was scant discussion through race action plan meetings of the technology deployment even with obvious cross-over with the strategy's goals.

“This disclosure demonstrate once again that the anti-racism commitments policing has undertaken via the race action plan are not being translated into wider practice. Our reports have warned that innovative tools are being implemented in a landscape where ethnic inequalities, weak scrutiny and poor data collection continue to exist.

“Any use of this technology must adhere to rigorous official guidelines, be subject to external review, and demonstrate it reduces rather than compounds ethnic bias.”

Official Statement

A Home Office spokesperson said: “We treat the conclusions of the report with utmost gravity and we have already taken action. A new algorithm has been externally evaluated and acquired, which has demonstrated no measurable discrimination. 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 taken without specialist personnel carefully reviewing the results.”