UK Police Forces Campaign to Use Biased Facial Recognition Systems

Law enforcement agencies across the UK effectively campaigned to deploy a facial recognition system acknowledged as biased against women, young people, and individuals from ethnic minority groups, following complaints that a less biased version produced fewer investigative leads.

How the System Works

UK forces use the national police database to carry out retrospective facial recognition searches. This process entails matching a reference photograph of a suspect against a repository of more than 19 million custody photos to find possible hits.

Acknowledged Discrimination

The Home Office admitted last week that the system was biased. This admission followed a study by the government's National Physical Laboratory determined it incorrectly matched people of Black and Asian heritage and women at much greater frequency than Caucasian males. The Home Office said it “had acted on the findings”.

“It prompts the question of whether this technology only becomes effective if users accept discrimination in race and sex. Convenience is a poor argument for disregarding basic freedoms.”

Known Issue

Official papers reveal that this discriminatory flaw has been recognized for more than a year. Furthermore, police forces lobbied to reverse an earlier ruling that was intended to mitigate the problem.

Police bosses were informed of the system's bias in September 2024. The government-ordered NPL review concluded the system was had a higher probability to produce incorrect matches for images depicting women, Black people, and those aged 40 and under.

A Reversed Decision

In reaction, the national police leadership body mandated that the confidence threshold required for potential matches be increased to a point where the bias was significantly reduced.

However, this directive was overturned the following month after forces complained that the modified technology was producing fewer “useful lines of inquiry”. NPCC documents show the higher threshold cut the number of queries resulting in possible identifications from over half to a just under 15%.

Profound Inequalities

Although the Home Office and NPCC declined to specify what threshold is currently used, the latest independent review discovered the system could generate false positives for women of Black heritage almost 100 times more frequently than for Caucasian women at certain settings.

The ministry commented on these results: “Our evaluation found that in a specific scenarios the software is more likely to wrongly flag some demographic groups in its search results.”

Balancing Utility and Fairness

Outlining the impact of the temporary raise to the system's accuracy setting, the NPCC documents state: “The change significantly reduces the effect of discrimination across legally safeguarded attributes of ethnicity, age and sex but had a substantially detrimental effect on operational effectiveness”. The papers add that forces argued that “a previously useful tool now delivered results of limited benefit”.

Broader Rollout Plans

Meanwhile, the government has opened a two-and-a-half-month public review 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”.

Expert and Oversight Concerns

The chair of a police oversight board, head of the advisory panel for the police race action plan, commented: “There was very little consideration in equality strategy sessions of the technology deployment despite obvious cross-over with the strategy's goals.

“These revelations show once again that the pledges to combat discrimination the police has undertaken via the equality initiative are not being translated into wider practice. Independent assessments have cautioned that new technologies are being implemented in a landscape where racial disparities, inadequate oversight and poor data collection already persist.

“All deployment of facial recognition must adhere to rigorous official guidelines, be subject to external review, and demonstrate it reduces rather than compounds ethnic bias.”

Home Office Response

A Home Office spokesperson stated: “The Home Office takes the conclusions of the study with utmost gravity and we have already taken action. A updated software has been independently tested and procured, which has no statistically significant bias. It will be trialled 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 officer review in each stage of the process and no further action would be taken without trained officers carefully reviewing the output.”