UK Police Forces Lobbied to Employ Discriminatory Face Scanning Technology

Law enforcement agencies across the UK effectively campaigned to use a facial recognition system known to be biased against women, young people, and members of ethnic minority groups, following complaints that a more accurate version produced a reduced number of investigative leads.

The Technology in Practice

British police utilize the police national database (PND) to carry out retrospective facial recognition searches. This process involves comparing a “probe image” of a suspect against a repository of over 19 million mugshots to find potential matches.

Acknowledged Discrimination

The Home Office admitted last week that the system was biased. This admission came after a study by the National Physical Laboratory (NPL) determined it incorrectly matched Black and Asian people and women at much greater frequency than Caucasian males. The ministry said it “had acted on the findings”.

“It prompts the question of whether this technology only becomes effective if users tolerate biases in ethnicity and gender. Operational ease is a poor argument for overriding fundamental rights.”

Known Issue

Internal documents reveal that this discriminatory flaw has been known about for over twelve months. Furthermore, police forces argued to overturn an earlier ruling that was designed to address the problem.

Police bosses were informed of the algorithmic discrimination in late 2024. The Home Office-commissioned laboratory study concluded the system was had a higher probability to produce false positives for images depicting women, Black people, and those under 40 years old.

A Policy U-Turn

In reaction, the National Police Chiefs’ Council (NPCC) ordered that the accuracy setting required for potential matches be raised to a point where the bias was greatly diminished.

However, this decision was overturned the following month after forces complained that the modified technology was producing a lower number of “useful lines of inquiry”. Internal records show the higher threshold cut the proportion of queries that yielded possible identifications from 56% to a mere under 15%.

Severe Disparities

Although the authorities refused to say what threshold is now in operation, the latest independent review discovered the system could generate incorrect matches for Black women almost 100 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 wrongly flag some demographic groups in its search results.”

Operational Effectiveness vs. Bias

Outlining the impact of the temporary raise to the system's accuracy setting, the police records note: “This adjustment significantly reduces the impact of bias across legally safeguarded attributes of ethnicity, generation and gender but had a significant negative impact on police efficiency”. The papers add that forces complained that “a previously useful tool now delivered results of limited benefit”.

Broader Rollout Plans

Meanwhile, the government has launched a two-and-a-half-month consultation on its proposals to expand the use of biometric scanning systems. Policing minister the relevant minister has labeled the technology as the “biggest breakthrough since DNA matching”.

Criticism from Advisors and Monitors

Abimbola Johnson, head of the advisory panel for the national policing equality strategy, commented: “There was scant consideration through equality strategy sessions of the technology deployment even with clear relevance with the strategy's goals.

“This disclosure show once again that the pledges to combat discrimination the police has undertaken through the equality initiative are failing to be integrated into wider practice. Independent assessments have cautioned that innovative tools are being rolled out in a landscape where ethnic inequalities, inadequate oversight and poor data collection already persist.

“Any use of facial recognition must meet strict national standards, be subject to external review, and demonstrate it reduces rather than compounds racial disparity.”

Official Statement

A Home Office spokesperson stated: “The Home Office takes the findings of the study with utmost gravity and we have already taken action. A updated software has been independently tested and acquired, which has no statistically significant bias. It will be tested early next year and will be undergo evaluation.

“Our priority is ensuring public safety. This gamechanging technology will assist police to apprehend and prosecute offenders. There is human involvement in every step of the procedure and no further action would be pursued without specialist personnel meticulously examining the results.”