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Police forces across the UK successfully lobbied to use a facial recognition system known to be discriminatory against females, young people, and members of ethnic minority groups, following complaints that a less biased version produced fewer potential suspects.

The Technology in Practice

UK forces utilize the police national database (PND) to carry out searches using historical face recognition. This procedure entails matching a reference photograph of a suspect against a database of over 19 million custody photos to find potential matches.

Admitted Bias

The Home Office conceded last week that the technology was flawed. This admission followed a study by the National Physical Laboratory (NPL) found it incorrectly matched people of Black and Asian heritage and females at much greater frequency than Caucasian males. The Home Office stated it “took steps on the findings”.

“It prompts the question of whether facial recognition only becomes useful if users tolerate discrimination in ethnicity and sex. Operational ease is a weak argument for overriding basic freedoms.”

Known Issue

Internal documents reveal that this discriminatory flaw has been recognized for more than a year. Furthermore, police forces argued to overturn an initial decision that was designed to address the problem.

Senior officers were informed of the system's bias in September 2024. The government-ordered NPL review found the system was had a higher probability to produce false positives for photos of females, Black people, and those under 40 years old.

A Policy U-Turn

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

However, this directive was reversed the next month following complaints from police that the adjusted system was generating fewer “useful lines of inquiry”. NPCC documents indicate the stricter setting cut the proportion of queries resulting in possible identifications from over half to a mere 14%.

Profound Inequalities

Although the Home Office and NPCC refused to say what setting is now in operation, the latest independent review found the system could generate false positives for women of Black heritage almost 100 times more often than for white women at specific configurations.

The ministry stated on these findings: “The testing found that in a specific scenarios the algorithm is has a greater tendency to wrongly flag some demographic groups in its search results.”

Operational Effectiveness vs. Bias

Describing the impact of the brief increase to the system's accuracy setting, the NPCC documents state: “The change significantly reduces the impact of bias across protected characteristics of ethnicity, generation and sex but had a significant negative impact on police efficiency”. The papers add that police units argued that “a once effective tactic now delivered results of limited benefit”.

Broader Rollout Plans

Meanwhile, the UK administration has launched a two-and-a-half-month consultation on its proposals to expand the use of biometric scanning systems. Policing minister Sarah Jones has described the technology as the “most significant advance since DNA matching”.

Criticism from Advisors and Monitors

Abimbola Johnson, head of the independent scrutiny and oversight board for the national policing equality strategy, said: “There was scant consideration through race action plan meetings of the technology deployment even with obvious cross-over with the strategy's goals.

“These revelations show once again that the anti-racism commitments the police has undertaken through the race action plan are not being translated into broader operations. Independent assessments have warned that innovative tools are being implemented in a context where ethnic inequalities, weak scrutiny and poor data collection continue to exist.

“All deployment of facial recognition must adhere to strict national standards, be independently scrutinised, and demonstrate it reduces rather than exacerbates ethnic bias.”

Official Statement

A government representative stated: “We takes the findings of the study seriously and we have already taken action. A updated software has been externally evaluated and acquired, which has no statistically significant bias. It will be tested early next year and will be undergo evaluation.

“The foremost aim is ensuring public safety. This revolutionary tool will assist police to apprehend and prosecute offenders. There is officer review in each stage of the process and no arrest or charge would be pursued without trained officers carefully reviewing the results.”