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Law enforcement agencies across the UK successfully lobbied to use a face scanning system known to be biased against females, young people, and members of minority ethnic backgrounds, after complaining that a less biased version produced fewer investigative leads.

How the System Works

UK forces 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 repository of more than 19 million mugshots to find possible hits.

Acknowledged Discrimination

The Home Office conceded last week that the system was flawed. This acknowledgment came after a review by the National Physical Laboratory (NPL) found it misidentified Black and Asian people and females at significantly higher rates than Caucasian males. The ministry said it “had acted on the findings”.

“It prompts the issue of whether facial recognition only becomes useful if users tolerate biases in race and sex. Convenience is a poor argument for disregarding basic freedoms.”

Known Issue

Official papers show that this bias has been recognized for more than a year. Furthermore, law enforcement lobbied to reverse 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 incorrect matches for photos of females, Black people, and those under 40 years old.

A Reversed Decision

In response, the national police leadership body ordered that the accuracy setting required for potential matches be raised to a level where the disparity was greatly diminished.

However, this directive was reversed the next month following complaints from police that the modified technology was generating a lower number of “useful lines of inquiry”. Internal records indicate the stricter setting reduced the number of searches that yielded possible identifications from 56% to a mere under 15%.

Profound Inequalities

Although the Home Office and NPCC refused to say what setting is now in operation, the latest independent review discovered the system could produce false positives for Black women almost 100 times more frequently than for white women at certain settings.

The Home Office commented on these results: “The testing 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 impact of the temporary raise to the system's confidence threshold, the police records note: “The change significantly reduces the effect of discrimination across protected characteristics of ethnicity, generation and gender but had a significant negative impact on operational effectiveness”. The documents add that police units argued that “a previously useful tool returned outcomes of limited benefit”.

Broader Rollout Plans

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

Criticism from Advisors and Monitors

The chair of a police oversight board, head of the independent scrutiny and oversight board for the national policing equality strategy, commented: “We observed scant discussion in race action plan meetings of the facial recognition rollout despite clear relevance with the strategy's goals.

“This disclosure demonstrate once again that the anti-racism commitments policing has undertaken via the race action plan are failing to be integrated into broader operations. Our reports have cautioned that innovative tools are being implemented in a landscape where ethnic inequalities, weak scrutiny and poor data collection already persist.

“All deployment of this technology must meet rigorous official guidelines, be subject to external review, and demonstrate it diminishes rather than compounds racial disparity.”

Official Statement

A government representative said: “We takes the findings of the study seriously and we have already taken action. A updated software has been independently tested and acquired, which has demonstrated no measurable discrimination. It will be tested in the coming months and will be undergo further assessment.

“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 procedure and no further action would be taken without trained officers carefully reviewing the results.”