British Law Enforcement Agencies Campaign to Employ Discriminatory Face Scanning Technology

Law enforcement agencies across the UK effectively campaigned to deploy a face scanning system known to be biased against women, young people, and individuals from minority ethnic backgrounds, after complaining that a less biased version produced fewer investigative leads.

The Technology in Practice

British police utilize the national police database to carry out searches using historical face recognition. This process entails matching a “probe image” of a suspect against a database of over 19 million custody photos to identify potential matches.

Admitted Bias

The UK interior ministry admitted last week that the technology was flawed. This admission came after a study by the National Physical Laboratory (NPL) determined 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 issue of whether this technology only becomes useful if users accept biases in race and gender. Operational ease is a poor argument for overriding fundamental rights.”

Long-Standing Problem

Official papers show that this discriminatory flaw has been known about for more than a year. Furthermore, law enforcement argued to overturn an earlier ruling that was designed to mitigate the problem.

Police bosses were informed of the system's bias in late 2024. The government-ordered laboratory study concluded the system was more likely to produce false positives 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 possible hits be raised to a point where the bias was significantly reduced.

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

Severe Disparities

Although the authorities refused to say what setting is now in operation, the recent independent review found the system could produce incorrect matches for women of Black heritage almost 100 times more often than for Caucasian women at certain settings.

The Home Office stated on these findings: “The testing identified that in a specific scenarios the algorithm is has a greater tendency to incorrectly include some population segments in its match reports.”

Operational Effectiveness vs. Bias

Describing the effect of the temporary raise to the system's confidence threshold, the NPCC documents note: “The change greatly lessens the impact of bias across protected characteristics of ethnicity, age and gender but had a substantially detrimental effect on operational effectiveness”. The documents add that forces argued that “a previously useful tool returned outcomes of questionable value”.

Wider Implementation Proposals

Meanwhile, the UK administration has launched a ten-week consultation on its proposals to expand the use of facial recognition technology. Policing minister Sarah Jones has described the technology as the “most significant advance since DNA matching”.

Expert and Oversight Concerns

Abimbola Johnson, head of the advisory panel for the national policing equality strategy, said: “There was very little discussion through race action plan meetings of the technology deployment despite clear relevance with the plan’s concerns.

“This disclosure show yet again that the anti-racism commitments policing has undertaken through the equality initiative are failing to be integrated into wider practice. Independent assessments have warned that innovative tools are being rolled out in a landscape where ethnic inequalities, weak scrutiny and faulty information gathering continue to exist.

“All deployment of this technology must adhere to strict national standards, be independently scrutinised, and prove it diminishes rather than compounds racial disparity.”

Official Statement

A Home Office spokesperson stated: “The Home Office treat the conclusions of the report seriously and we have already taken action. A updated software has been externally evaluated and procured, which has demonstrated no measurable discrimination. It will be tested in the coming months and will be undergo evaluation.

“The foremost aim is protecting the public. This revolutionary tool will support police to apprehend and prosecute offenders. There is human involvement in each stage of the process and no further action would be pursued without trained officers meticulously examining the results.”