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Law enforcement agencies across the UK successfully lobbied to use a facial recognition system acknowledged as biased against women, youths, and individuals from ethnic minority groups, after complaining that a less biased version generated a reduced number of investigative leads.

How the System Works

British police use the national police database to carry out searches using historical face recognition. This procedure involves comparing a reference photograph of a suspect against a database of more than 19 million custody photos to find possible hits.

Acknowledged Discrimination

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

“This raises the question of whether this technology only becomes effective if users tolerate biases in ethnicity and gender. Convenience is a weak argument for disregarding basic freedoms.”

Long-Standing Problem

Internal documents reveal that this bias has been recognized for over twelve months. Furthermore, police forces lobbied to reverse an initial decision that was designed to address the problem.

Police bosses were notified of the algorithmic discrimination in late 2024. The Home Office-commissioned laboratory study found the system was had a higher probability to produce incorrect matches for images depicting females, Black people, and those aged 40 and under.

A Policy U-Turn

In response, the National Police Chiefs’ Council (NPCC) mandated 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 following month following complaints from police that the modified technology was producing fewer “useful lines of inquiry”. Internal records show the stricter setting reduced the number of queries that yielded possible identifications from over half to a mere under 15%.

Severe Disparities

Although the authorities refused to say what threshold is currently used, the latest independent review found the system could produce incorrect matches for Black women nearly a hundred times more frequently than for white women at specific configurations.

The ministry stated on these results: “The testing identified that in a limited set of circumstances the algorithm is has a greater tendency to incorrectly include some population segments in its match reports.”

Balancing Utility and Fairness

Outlining the impact of the brief increase to the system's confidence threshold, the police records note: “This adjustment significantly reduces the impact of discrimination across legally safeguarded attributes of race, age and sex but had a substantially detrimental effect on police efficiency”. The documents further note that police units argued that “a previously useful tool returned outcomes of limited benefit”.

Broader Rollout Plans

Meanwhile, the UK administration has launched a two-and-a-half-month consultation on its plans to widen the use of biometric scanning systems. Policing minister the relevant minister has described the tool as the “biggest breakthrough since genetic fingerprinting”.

Expert and Oversight Concerns

The chair of a police oversight board, head of the advisory panel for the national policing equality strategy, said: “There was very little discussion through race action plan meetings of the facial recognition rollout despite obvious cross-over with the plan’s concerns.

“This disclosure demonstrate once again that the pledges to combat discrimination the police has made via the equality initiative are failing to be integrated into broader operations. Independent assessments have cautioned that new technologies are being rolled out in a landscape where ethnic inequalities, inadequate oversight and faulty information gathering already persist.

“All deployment of this technology must adhere to strict national standards, be subject to external review, and demonstrate it reduces rather than compounds ethnic bias.”

Home Office Response

A government representative stated: “The Home Office treat the findings of the report seriously and we have already taken action. A updated software has been independently tested and procured, which has demonstrated no measurable discrimination. It will be tested in the coming months and will be subject to evaluation.

“Our priority is protecting the public. This revolutionary tool will support officers to put criminals and rapists behind bars. There is human involvement in each stage of the process and no arrest or charge would be taken without specialist personnel carefully reviewing the results.”