British Police Forces Lobbied to Use Discriminatory Facial Recognition Systems

Law enforcement agencies across the United Kingdom effectively campaigned to deploy a facial recognition system known to be discriminatory against women, youths, and individuals from minority ethnic backgrounds, following complaints that a less biased version generated a reduced number of investigative leads.

How the System Works

UK forces utilize the police national database (PND) to carry out searches using historical face recognition. This process involves comparing a “probe image” of a person of interest against a database of more than 19 million mugshots to find potential matches.

Acknowledged Discrimination

The UK interior ministry admitted last week that the technology was biased. This admission came after a review by the National Physical Laboratory (NPL) determined it misidentified people of Black and Asian heritage and females at significantly higher rates than white men. The Home Office said it “had acted on the findings”.

“This raises the issue of whether facial recognition only becomes effective if users tolerate biases in race and gender. Operational ease is a poor argument for disregarding fundamental rights.”

Long-Standing Problem

Official papers reveal that this bias has been known about for over twelve months. Furthermore, police forces 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 government-ordered laboratory study concluded the system was had a higher probability to produce false positives for images depicting females, individuals of Black ethnicity, and those under 40 years old.

A Reversed Decision

In reaction, the national police leadership body ordered that the confidence threshold required for potential matches be raised to a point where the bias was greatly diminished.

However, this directive was overturned the following month following complaints from police that the adjusted system was producing fewer “useful lines of inquiry”. NPCC documents show the higher threshold reduced the proportion of searches that yielded potential matches from over half to a mere 14%.

Severe Disparities

Although the authorities refused to say what setting is now in operation, the recent NPL study found the system could produce false positives for women of Black heritage nearly a hundred times more often than for white women at certain settings.

The ministry commented on these results: “Our evaluation identified that in a limited set of circumstances the algorithm is has a greater tendency to incorrectly include some demographic groups in its search results.”

Balancing Utility and Fairness

Outlining the impact of the brief increase to the system's confidence threshold, the NPCC documents note: “This adjustment greatly lessens the effect of bias across protected characteristics of ethnicity, generation and gender but had a significant negative impact on police efficiency”. The documents further note that police units argued that “a previously useful tool now delivered outcomes of questionable value”.

Broader Rollout Plans

Meanwhile, the government has launched a two-and-a-half-month consultation on its proposals to expand the use of facial recognition technology. Policing minister Sarah Jones has labeled the technology as the “most significant advance since genetic fingerprinting”.

Criticism from Advisors and Monitors

Abimbola Johnson, head of the independent scrutiny and oversight board for the national policing equality strategy, said: “We observed scant consideration through race action plan meetings of the technology deployment despite obvious cross-over with the plan’s concerns.

“This disclosure demonstrate yet again that the anti-racism commitments the police has undertaken through the race action plan are not being translated into broader operations. Our reports have warned that new technologies are being rolled out in a landscape where ethnic inequalities, weak scrutiny and poor data collection already persist.

“All deployment of facial recognition must meet rigorous official guidelines, be independently scrutinised, and prove it diminishes rather than compounds racial disparity.”

Official Statement

A Home Office spokesperson stated: “The Home Office treat the conclusions of the study with utmost gravity and we have implemented changes. A new algorithm has been independently tested and procured, which has no statistically significant bias. It will be tested in the coming months and will be undergo evaluation.

“Our priority is ensuring public safety. This revolutionary tool will support police to put criminals and rapists behind bars. There is human involvement in every step of the process and no further action would be pursued without trained officers meticulously examining the results.”