British Law Enforcement Agencies Lobbied to Use Biased Facial Recognition Systems

Law enforcement agencies across the United Kingdom effectively campaigned to deploy a facial recognition system acknowledged as biased against women, youths, and members of minority ethnic backgrounds, following complaints that a less biased version produced a reduced number of investigative leads.

The Technology in Practice

British police use the national police database to conduct retrospective facial recognition searches. This process entails matching a “probe image” of a suspect against a database of over 19 million mugshots to find possible hits.

Acknowledged Discrimination

The UK interior ministry admitted last week that the system was biased. This admission followed a study by the National Physical Laboratory (NPL) found it misidentified Black and Asian people and women at much greater frequency than white men. The Home Office stated it “had acted on the findings”.

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

Long-Standing Problem

Official papers reveal that this discriminatory flaw has been recognized for more than a year. Furthermore, law enforcement argued to overturn an initial decision that was intended to mitigate the problem.

Senior officers were notified of the algorithmic discrimination in September 2024. The Home Office-commissioned laboratory study found the system was had a higher probability to produce incorrect matches for images depicting women, Black people, and those aged 40 and under.

A Policy U-Turn

In response, the National Police Chiefs’ Council (NPCC) ordered that the accuracy setting required for possible hits be increased to a point where the disparity was significantly reduced.

However, this directive was reversed the following month after forces complained that the adjusted system was producing fewer “investigative leads”. NPCC documents indicate the stricter setting reduced the proportion of queries that yielded possible identifications from over half to a just 14%.

Severe Disparities

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

The ministry stated on these results: “Our evaluation identified that in a limited set of circumstances the software is has a greater tendency to incorrectly include some population segments in its search results.”

Operational Effectiveness vs. Bias

Describing the effect of the temporary raise to the system's confidence threshold, the police records note: “This adjustment greatly lessens the impact of discrimination across protected characteristics of ethnicity, age and gender but had a significant negative impact on operational effectiveness”. The papers add that police units argued that “a previously useful tool returned results of questionable value”.

Broader Rollout Plans

Meanwhile, the UK administration has opened a two-and-a-half-month consultation on its proposals to widen the use of biometric scanning systems. Policing minister Sarah Jones has labeled the tool as the “biggest breakthrough since genetic fingerprinting”.

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, said: “There was very little consideration in equality strategy sessions of the technology deployment even with clear relevance with the strategy's goals.

“These revelations demonstrate yet again that the anti-racism commitments the police has made through the race action plan are not being translated into wider practice. Independent assessments have warned that new technologies are being implemented in a context where racial disparities, weak scrutiny and faulty information gathering already persist.

“All deployment of this technology must meet strict national standards, be subject to external review, and prove it diminishes rather than compounds racial disparity.”

Home Office Response

A Home Office spokesperson stated: “The Home Office takes the findings of the report seriously and we have implemented changes. A updated software has been externally evaluated and acquired, which has demonstrated no measurable discrimination. It will be tested in the coming months and will be undergo evaluation.

“Our priority is protecting the public. This revolutionary tool will assist officers to apprehend and prosecute offenders. There is officer review in every step of the process and no further action would be taken without specialist personnel meticulously examining the results.”