UK Police Forces Lobbied to Employ Discriminatory Facial Recognition Systems

Police forces across the United Kingdom successfully lobbied to use a facial recognition system acknowledged as biased against women, young people, and members of ethnic minority groups, after complaining that a less biased version produced a reduced number of investigative leads.

The Technology in Practice

British police use the police national database (PND) to conduct searches using historical face recognition. This process involves matching a reference photograph of a person of interest against a database of over 19 million mugshots to find potential matches.

Acknowledged Discrimination

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

“This raises the question of whether facial recognition only becomes effective if users tolerate discrimination in ethnicity and sex. 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, police forces argued to overturn an initial decision that was intended to address the problem.

Police bosses 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 false positives for photos of women, individuals of Black ethnicity, and those under 40 years old.

A Policy U-Turn

In reaction, the National Police Chiefs’ Council (NPCC) ordered that the accuracy setting required for possible hits be raised to a point where the disparity was greatly diminished.

However, this decision was reversed the following month following complaints from police that the modified technology was producing a lower number of “useful lines of inquiry”. NPCC documents show the higher threshold cut the proportion of queries that yielded potential matches from 56% to a just under 15%.

Severe Disparities

Although the Home Office and NPCC refused to say what threshold is now in operation, the latest NPL study discovered the system could produce incorrect matches for Black women almost 100 times more often than for Caucasian women at specific configurations.

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

Operational Effectiveness vs. Bias

Describing the effect of the temporary raise to the system's accuracy setting, the NPCC documents note: “The change greatly lessens the impact of discrimination across legally safeguarded attributes of ethnicity, age and gender but had a substantially detrimental effect on police efficiency”. The papers further note that police units argued that “a previously useful tool now delivered results of limited benefit”.

Broader Rollout Plans

Meanwhile, the government has opened a ten-week public review on its plans to expand the use of facial recognition technology. The minister for police Sarah Jones has described the tool as the “biggest breakthrough since DNA matching”.

Expert and Oversight Concerns

Abimbola Johnson, chair of the independent scrutiny and oversight board for the police race action plan, said: “We observed very little consideration through race action plan meetings of the facial recognition rollout even with obvious cross-over with the plan’s concerns.

“This disclosure demonstrate once again that the anti-racism commitments the police has undertaken via the race action plan are not being translated into broader operations. Our reports have warned that new technologies are being rolled out in a context where racial disparities, weak scrutiny and faulty information gathering continue to exist.

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

Official Statement

A Home Office spokesperson said: “The Home Office takes the conclusions of the report with utmost gravity and we have implemented changes. A updated software has been independently tested and procured, which has no statistically significant bias. It will be tested in the coming months and will be subject to evaluation.

“The foremost aim is protecting the public. This revolutionary tool will assist 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 trained officers meticulously examining the output.”